Channel 11-khou 11-Tv Interview Midtown Auto Service 2008-houston-tx
November 21st, 2008JUNE 2008 FEATURED ARTICLE-BEST AUTO REPAIR SHOP HOUSTON-MIDTOWN AUTO SERVICE
June 11th, 2008Award-Winning Shop Lives by Golden Rule
Posted 6/1/2008
By Leona Dalavai Scott

Shop Stats
Name: Midtown Auto Service
Location: Houston, Texas
Web site: www.midtownautoservice.net
Square footage of shop: 6,000 square feet
Repairs per week: 150 cars
No. of years in business: 21 years
On his success rate with retaining technicians: “I offer my technicians two weeks of paid vacation during Christmas and New Year’s after they’ve been employed with me for a year. Also, I treat them and their spouses to dinners and lunches on random occasions. I try to let them take care of family or personal business without penalties. All of my techs have their own computers with Internet access to Alldata and Identifix. Things like that really make a person want to stay.”
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Mikey credits his prime location for business staying strong even during tough economic times. |
Mikey Yu is not your average shop owner. With a criminal justice degree from the University of Houston, he always wanted to be a cop.
But when his dad retired in 1998, Mikey thought that it would be a smart move to buy the shop from him. Within four years of taking over the shop, he expanded the facility from 2,900 square feet to 6,000 square feet. Along the way, he earned his ASE
certification to become an auto technician.
Mikey is also a state-certified inspector and his shop, Midtown Auto Service, is a state-certified emissions and repair facility. The shop is known in the community for its engine and emissions diagnostic capabilities and for solving electrical driveability issues for all makes and models.
Mikey says his shop’s strength stems from the way it treats its customers and its technicians. He conducts his business by the golden rule: “Do to others as you would have them do to you.” He believes you should treat your customers and employees the way you would want to be treated.
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ASE certified master tech Richard Kline working on a 2004 Lexus ES 300 timing belt. |
“And if you treat your employees as family members instead of just a number, I think that productivity increases,” Mikey says. Midtown Auto Service employs two L1 master auto techs and another master auto tech. Mikey’s wife, Sharon, handles all of the administrative work in the office while Mikey takes care of the “heart of the business,” which he sees as fielding questions and calls from customers and handling technician concerns and problems.
“Our line of work is difficult,” Mikey explains. “The customers who bring their cars and trucks to us normally know nothing about repairing their cars but have heard horror stories about other automotive service shops in the past. So, you start building a rapport with customers and listen to issues about their car. Just listen. Listening is very important. That can help break the barrier of customer distrust from the beginning.”
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Master ASE Certified Tech Byung Young working on a car using his 1/2 cordless SnapOn gun. |
As a result of his business philosophy, Mikey has experienced great success with Midtown Auto Service. In 2007, the shop was named the “Best Auto Shop” by Citysearch, a popular Web site that enables users to post opinions on just about anything, including recommendations for services such as auto care. In 2006, the shop was named “Best Auto Repair Shop” by the local newspaper. In addition, the shop is a AAA-approved auto repair facility and a recognized emissions repair facility.
Mikey also shares his knowledge and expertise of cars through articles in Undercar Digest and Automotive Report. He has also been featured on “Car Talk,” an entertaining radio show about automotive service issues that is broadcast on National Public Radio.
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ASE L1 MASTER AUTO TECHNICIAN; Panda Lee is working on an electrical drain/short on a 2006 Jaguar S-type. |
As he looks toward the future, Mikey would like to expand his shop. He is currently trying to acquire the land next to his so he can double his shop size to 12,000 square feet or more. However, real estate in his area has skyrocketed so he is proceeding on those plans with caution. Despite the downturn in the economy, Mikey says Midtown Auto Service’s business has been good as a result of its prime location between downtown and the medical districts of Houston.
As Mikey celebrates the success of Midtown Auto Service, the thing he is most proud of, he said, is the teamwork his employees exhibit in working with the motoring public. As his accolades and accomplishments show, this teamwork is paying off nicel
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AAA APPROVED AUTO REPAIR FACILITY HOUSTON-MIDTOWN AUTO SERVICE
March 13th, 2008We are a Texas Approved AAA Auto Repair Facility in Houston. Also, we are an Independent Auto Care/Repair Factory Dealer Service Center for AC Delco in Houston, with ASE Certified Technicians. Recognized by the state of Texas, Midtown Auto Service & Repair is licenced to issue auto inspections on all types of vehicles.
Being a State Recognized Emmission Repair Facility we offer low income waivers, low milage waivers, individual vehicle waivers, to everyone who failed their state / emmission inspections. Also, some of our services include, auto engine diagnostics, auto engine repair, auto engine misfires, auto check engine light on, auto overheating problems, auto emissions failures, auto drivability issues, brakes,alignments,complete exhaust repairs,tire balancing & rotations, timing belts, waterpumps, auto electrical troubleshooting, doors & windows, oil changes,shocks/struts,A/C work,state inspections and much much more.
We have been featured in magazines such as Undercar Digest, Tech Shop and Automotive Report. These magazines were contacted by other auto repair shop owners and customers who reported us worthy as a featured story. Midtown Auto Service is honored by these recognitions of these auto technical trade magazines. Which is considered a great achievement from our peers.
Also, Citysearch has awarded Midtown Auto Service as Best Auto Repair Shop 2006-2007. Citysearch awarded us with a plaque, “Best Auto Repair 2006 – Audience Winner.” In 2007, Citysearch again awarded us with two rewards, “Best Auto Repair 2007 – Audience Winner & Editorial Winner.” Thus, making Midtown Auto Service the only auto service care facility in Houston, Texas to win two years in a row by Citysearch.
In addition, Midtown Auto Service have won other coveted national recognitions, such as, “Yahoo 2005 Best & Trusted Auto Care Facility” and by “The Local Newspaper – The Best Auto Service 2006.” We are also listed in a national radio broadcast, “Car Talk” as listed as a good repair shop to visit in Houston in their “mechanics file.”
Come and try us out and see the difference, we are conveniently located between the downtown & medical center, also known as Midtown.
In conclusion, we service all foreign, domestic and most european cars. In addition, we take checks and all 4 major credit cards,( checks, MasterCard, Visa, Discover, & American Express)
CHECK US OUT ON OUR WEBSITE:
Contact: (713) 523-2886
AUTO REPAIR SERVICE HOUSTON-MIDTOWN AUTO SERVICE
March 6th, 2008Welcome! It’s our goal at Midtown Auto Service & Repair Shop in Houston to always provide great service and high-quality workmanship at a fair price. Midtown Auto Service & Repair is a family-owned business that has specialized in providing personalized service to our customers.
Since 1987, Midtown Auto Service & Repair Shop in Houston has been committed to providing the highest quality automobile repair service at affordable prices. We have established our auto repair business on sound ethical and moral principles. Simply put, our Houston auto repair business focuses on customer service, and your satisfaction is paramount. We want you to be pleased with our services so that you will continue to use us for your automobile repair-service needs in the future and tell your friends.
Our skill and knowledge about automobiles enable us to address a broad range of auto repair-services of mechanical issues, which means you’ll experience a higher, more comprehensive level of service and greater value with us.
How do we do it? We listen. Hearing your opinions, observations and concerns make it possible for us to work with you as a team. By earning your trust, we can better guide you toward solutions that meet your specific needs about your car auto repair services.
At Midtown Auto Service & Repair , you’ll always get a clear explanation of what’s happenings with your car, as well as whatever options you should be aware of when making your maintenance and auto repair decisions. That’s our commitment to you. Please browse around our website to learn more about us and our commitment to provide you with the best service possible.
One of the highest recognitions for an auto repair shop in Houston is given by the State of Texas to be a Recognized Auto Repair and Emmissions Repair Facility. In turn, it gives us privileges from the State of Texas for issuing Automotive Repair and Replacement Assistance in Houston & the surrounding areas. In 2007, there were less than 100 automotive repair shops in Houston that had this license by the State. That is a big disproportion considering there are over 3400 auto repair shops in Houston and the surrounding areas. Another factor to being a highly recognized Houston auto repair shop is being chosen by General Motors Inc. as an independent Auto Repair Service Center: AC Delco Factory Houston Auto Repair Facility. NAPA Auto Parts also endorses our company as an Approved Napa Auto Car Care Repair Center in Houston which means that their company certifies us to do their repair warranties or any needed repairs. Also, our shop is an AAA Approved Auto Repair Facility that employs only ASE certified auto technicians. Operating since 1987, we are conveniently located between the downtown & medical center, also known as Midtown.
CHECK US OUT ON OUR WEBSITE:
Contact: (713) 523-2886
STEERING GEARS RACK AND PINION STEERING GEARS-STEERING ASSIST-DIAGNOSTIC TIPS AUTO REPAIR HOUSTON,TX
February 5th, 2008Diagnostic Solutions
STEERING GEARSKeeping Your Customers’ Vehicles on The Straight & Narrowby Gary Goms, Import Specialist ContributorModern automotive steering gears evolved from the quaint tiller-controlled steering systems used in the first automobiles to the hydraulically controlled systems now used in most import vehicles. Unfortunately, steering tillers that attached to axles with little or no steering geometry didn’t provide much steering feedback from the road surface. When vehicle speeds approached 20 mph, auto manufacturers began to incorporate more sophisticated steering systems to help the driver keep the vehicle traveling in a straight line.As vehicles became heavier and more difficult to steer, auto manufacturers developed different types of steering gears designed to change the rotating motion of the steering wheel and shaft into a lateral motion transmitted through the steering linkage to the steering knuckles and front wheels. This system has prevailed to this day.KINGPIN INCLINATION
As steering gear technology progressed, innovations in steering geometry also aided steering gear functions. The popular introduction of kingpin inclination (KPI) during the early 1920s, for example, eased steering effort by tilting the kingpin inward at the top, so that a line drawn through the kingpin angle intersects with the center of the tire tread. KPI is also present in ball joint or MacPherson strut systems, with the angle of the upper and lower ball joints or MacPherson strut intersecting with the center of the tire tread. KPI actually accomplishes three separate, but related, steering functions. First, KPI reduces steering effort by allowing the tire to pivot on the center of its tread rather than be swung around the axis of a vertical kingpin. Second, KPI greatly reduces the probability that a wheel striking a pothole may suddenly spin the steering wheel out of the driver’s hands. Third, KPI actually lifts one side of the vehicle and lowers the other as the wheels are turned. This lifting effect, combined with caster angle, forces the front wheels to return to a straight-ahead position. For all of the above reasons, steering effort increases and the steering wheel becomes more sensitive to road shock whenever offset custom wheels are installed on a vehicle.
THE ROLE OF CASTER ANGLE
Caster angle also plays a function in all steering gear systems. Positive caster angle can be easily visualized in the backward tilt of a bicycle’s front fork. Positive caster angle, of course, allows the bicycle to steer itself when the rider takes his hands off the handlebars. Although some auto manufacturers may employ negative caster angle to accomplish the same purpose, caster helps force the front wheels to return to center when the driver releases the steering wheel.
CONVENTIONAL STEERING GEARS
Although conventional parallelogram steering linkage systems are being replaced by the more modern rack and pinion steering gears, many heavier vehicles such as luxury sedans and pickup trucks still use conventional steering gears. Early steering gears were crude, bronze-bushed units that required a great amount of steering effort to turn the wheels. As vehicles became heavier, ball and needle-roller bearings were used to reduce friction in the steering gear assembly. In addition, a recirculating ball-bearing worm gear assembly was introduced that greatly reduced friction between the worm gear mounted on the steering gear input shaft and the sector gear mounted on the steering output shaft.
As vehicle speeds increased, it became very important for the steering gear to transmit a sense of “road feel” to the driver. Without a fine-tuned sense of steering wheel center, it became difficult for a driver to drive in a straight line at high speed. To accomplish this, engineers designed a worm and sector gear that would develop zero clearance or lash when the steering gear operated in the centered or straight-ahead position. The fact that the steering gear ‘tightens” up when the front wheels are in the straight-ahead position gives the driver a much finer sense of when the vehicle is tracking in a straight line.
As the wheels are turned, the steering gear rolls off the “high spot” and develops clearance between the worm and sector gears. This added clearance reduces friction and helps the front wheels return to the straight-ahead position when the driver releases the steering wheel. In addition, the high spot in the steering gear tends to stop or hold the steering gear in the straight-ahead position by increasing friction between the worm and sector gears. This particular feature helps prevent the driver from over-steering the vehicle.
RACK-AND-PINION STEERING GEARS
Rack and pinion steering gears were popularly introduced into the import market during the 1950s because they provided fast steering wheel response and had fewer parts. In this system, a rack gear is attached to the right and left steering knuckles by tie rods that swivel to allow vertical movement in the suspension system. The pinion gear, of course, is attached to the steering shaft and moves the rack in a lateral direction in response to steering wheel input. Like the conventional steering gear, the rack and pinion is machined to decrease gear lash as the steering wheel returns to the center position.
STEERING ASSIST
Steering assist systems incorporate a hydraulic pump driven by an engine accessory drive belt to provide pressure to a steering assist cylinder attached to the sector gear in conventional systems or the rack gear in rack and pinion systems.
To provide full steering assist, the power steering pump must produce at least 1,000 psi pressure upon demand. Because a power steering pump is used only a small percentage of time, the pump is equipped with a hydraulic boost or computer-controlled, pulse-modulated valve assembly that allows it to free-wheel during highway driving. To fine-tune steering wheel response, the steering gear shaft is equipped with a torsion bar that opens a metering valve as torque is applied to the steering wheel. Due to the action of the torsion bar, the amount of oil pressure metered to the steering assist cylinder is directly proportional to the torque being applied to the steering wheel.
The metering valve assembly is very sensitive because it’s often equipped with compressible reaction discs that further increase the steering gear’s sensitivity to steering wheel torque. Some manufacturers, such as Honda, have used axle-driven mechanical systems that limit power steering assist to low-speed driving situations. In other applications, steering pump pressure may be controlled by using a pulse-width modulation system that varies pressure in response to steering wheel demand and highway speed.
DIAGNOSTIC TIPS
On high-mileage vehicles with a steering wander complaint, the sector gear lash might require adjusting to eliminate excessive lash between the worm and sector gears. Early manual rack and pinion gears also have a similar adjustment that reduces lash between the pinion and rack gears.
A steering gear may also transmit steering feedback to the driver only when it’s installed in the centered position. In most cases, a four-wheel alignment may be required to recenter the steering gear. The first step is to always make sure that indexing marks on the steering wheel and steering shaft are aligned. The last step is to adjust front and rear toe angles to correspond with the vehicle’s centerline or thrust angle. When removing the steering wheel, always follow the manufacturers’ instructions regarding the disarming of the air bag and preventing damage to the air bag clock spring.
Any power steering gear can develop a “lack of assist” complaint. Generally speaking, a worn power steering pump is usually indicated if steering assist deteriorates as the steering oil begins to warm up and lose viscosity. In contrast, some rack and pinion steering gears may develop an intermittent condition called “morning sickness.” This particular lack of steering assist is caused by the metering valve oil seals wearing grooves into the soft aluminum steering gear housing. As the steering gear oil warms up, the valve assembly reseals itself to the housing and restores steering assist. Because special tools and expertise might be required to rebuild a steering gear, it’s more cost-effective to install a new or remanufactured gear than to repair or rebuild an old one.
Last, it’s always important to use application-specific power steering fluid in import applications. In the case of Honda, using non-OE specification fluid can ruin the steering gear seals. In other applications, using the wrong fluid or mixing fluids can cause the steering fluid to foam, which may cause a howling noise and temporary reduction of steering assist.
CAR-AUTO-ENGINE P0401 ENGINE CODES EGR PROBLEMS-NOx EMMISSIONS PROBLEMS-HOUSTON,TX
February 1st, 2008
EGR ISSUESDealing with P0401 Codesby Bob DowieExhaust gas recirculation (EGR) has been used for years to control combustion temperature to prevent spark knock as well as control NOx emissions. For the most part, these systems were trouble-free and required service only if you were dealing with a spark knock issue, or if the valve opened too early, resulting in a tip-in acceleration stumble, or the more common, bad idle quality caused by the valve not closing completely at idle. ![]() We’ll start with the four-cylinder Accord engines. While there have been some reports of problems with the Civic, problems with the Accord have been the most prevalent. Driveability complaints are more common than check engine lights on these models through the ‘90s. What you’ll be faced with is a stumble complaint, which is actually a misfire at part-throttle, that’s most prevalent on initial acceleration when the EGR valve is commanded to open. It feels almost like a bad wire and happens just when you’d expect a secondary ignition problem — part-load acceleration. The cause of the misfire is an excess of recycled exhaust gasses in one or more cylinders. The cause of this excess flow is actually plugged passages in the manifold leading to the other cylinders. When there is no flow to those cylinders, the remaining cylinders receive all the exhaust gasses, which cause the miss. This problem has caused a great deal of frustration with techs, resulting in a lot of misdiagnosis. That’s not very surprising considering how well this problem mimics a secondary ignition problem. Then, to further confuse the issue, if there is a CEL, it’s often for the misfire and not the EGR system. Up until 1998, when the electronically controlled EGR valves were introduced, Honda looked at the EGR lift sensor to confirm that the valve received vacuum and opened, and that flow was taking place. Since the valve is opening, the ECU figures all is well there, but it’s well trained to pick up a misfire and is quick to report any problem that would hurt the catalytic converter. MISDIAGNOSIS WOES You’ll probably get a check engine light but, if the miss is gone, you’ll know for sure that the EGR system is the culprit. But don’t overlook checking the ignition components. It’s good to know the miss is fixed, but there’s never a bad time to bring the car up-to-snuff on maintenance items. Plus, you wouldn’t want the car coming back with a bad cap, wires or plugs next week if you could’ve taken care of those items now. If disabling the EGR eliminated the miss, it’s time to clean out the passages. The procedure differs slightly depending on the year of the vehicle. The early cars used a blind core plug to seal the manifold runner EGR port after machining. We’ve found that the best way to remove these plugs is to drill a small hole partially into the plug, and using a self-tapping screw, or tapping the hole for a machine screw and using a small slide hammer, to pull them out. Partially drilling them will allow you to reuse the plugs if no replacements are on hand. Replacement plugs are available and there’s actually a kit from Honda that includes the tools and plug. Needless to say, caution is required when drilling or tapping. Grease up the drill bit and tap to catch as many of the chips as possible. Using a shop vac is a much better choice than compressed air to keep the area clean as you work. With the plugs removed, the blockage will be obvious and can be easily dislodged using a stiff wire and carb cleaner. Be sure to clean the entire port again to keep the vacuum running. This procedure is well outlined in service bulletin #98-074, which should be available on your service information system. The next era of four-cylinder cars saw the plugs replaced by a plate covering the EGR channel as well as the ports. This was a big improvement that eliminates the need to drill and allows us to better clean out any carbon buildup in the channel and the ports. Accessibility isn’t a problem, but the injectors will have to be removed. To be safe, you may want to have injector seals available, but they can often be reused. The latest of the four cylinders use a two-piece intake plenum with the EGR passages cast into the upper section. These cars don’t seem to suffer from the misfire problems of the earlier cars, but are more apt to have flow problems that will be picked up by the more observant OBD system setting a check engine light. To access the EGR ports and channel on these engines, split the intake and use a stiff wire to clean out the ports — a very similar procedure to the V6s that we’ll talk about next. In recent years, EGR problems seem to be most prevalent on V-6 engines used in the popular Odyssey minivan, Accords and SUVs; only the worst cases will present driveability symptoms. It will be the check engine light providing the motivation for the customer, using the same enhanced code-setting criteria as the late-model four cylinders. When Honda went to the electronically controlled sensor, they were now able to command the amount of lift, monitor the actual amount of lift and look at the MAP sensor making sure it had the expected effect on air flow. If anything unexpected happens on two trips, the check engine light will let the customer know. The EGR passages on the six cylinders are in the upper section of the intake manifold. Some of the gaskets are reusable, but if you’re going in, the safe bet is to at least have a throttle body gasket on hand. To get started:
CAUSES OF A P0401 CODE With the electrical connecter unplugged from the switching valve, introduce battery voltage to the black/yellow wire and apply ground to the red wire at the valve side of the electrical connector. If all is well, you’ll show vacuum on the gauge. As I said, these valves have a reputation for being intermittent, so repeat the test in quick succession looking for slow or no response on the gauge.
On the reporting side, the yellow and blue is the 5V reference signal from the ECU for the position sensor, the green and black is ECU ground, with the white and black sending the signal back to the ECU, letting it know how the EGR is responding to direction. An increase in operational duty cycle should result in a smooth increase in reporting voltage with no dropouts. Many scan tools will let you look at and log command and reporting data on a road test. Otherwise, with good access, it’s not difficult to back-probe the connector and get the same info on a multi-channel graphing meter. We can also use what we know about the wiring to check for blocked passages and the basic operation of the valve. With the electrical connector disconnected, the valve will open by putting battery power to the terminal that the pink wire is connected to and grounding the black wire terminal. If the ports are clear and the valve is working, the engine should quickly get rough or stall, and smooth out when the valve is closed. When diagnosing a driveability problem, it’s important to keep in mind if you have a problem on light acceleration at low RPM, when the EGR is commanded on, suspect the EGR system. Or, an intermittent rough idle may be the result of the valve not completely closing. Otherwise, the EGR system shouldn’t be suspected. If I can leave you with one solid tip for diagnosing and repairing EGR problems on the Honda line of vehicles, it’s to check your service information system for service bulletins. Honda does a great job of making this information available to the aftermarket, and it’s just foolish not to take advantage of it. If you’re not going online, checking for bulletins and making full use of services like iATN, import-car.com and OEM info like that available from Honda (www.techinfo.honda.com), you’re just leaving too much good information untapped. The way things are going, you won’t be able to afford doing that much longer. |
AUTO-CAR-FUEL-INJECTORS-DIAGNOSTIC-SERVICE-ENGINE PROBLEMS-HOUSTON,TX
February 1st, 2008
Is There Enough Pressure?Fuel Injection Diagnosis & ServiceBy Larry Carley, technical editorOne of the first questions that should always be asked — and answered — when diagnosing a fuel-related complaint on a fuel injected engine is, “What is the fuel pressure?” All too often, technicians assume fuel pressure is “good” without actually measuring it with a gauge. If the engine runs, they assume the injectors are getting adequate fuel pressure. If the engine cranks but won’t start, and they depress the service valve on the fuel rail and some fuel squirts out, they assume the injectors have pressure. They do, but the question remains, “How much pressure?” For the engine to start and run smoothly with no stalling, hesitation or misfiring, the injectors have to deliver the proper amount of fuel with every squirt. This is especially important on late-model engines with sequential fuel injection. One bad injector will cause a noticeable misfire and usually set a P030X misfire code (where X represents the cylinder that is misfiring). On older engines where the injectors are all fired simultaneously, the good injectors can often compensate for one or two bad injectors. Even so, for the engine to run right, fuel pressure to the injectors is critical as is the volume of fuel delivered by each injector when it fires.
It’s All About Fuel Pressure On certain Jaguar engines, for example, the factory spec calls for 37 psi of fuel pressure. If you see 36 psi or 38 psi, you need to replace the fuel pressure regulator. Fuel Volume Is Just As Important The old rule of thumb that says a “good” fuel pump will flow about a pint of fuel in 15 seconds (half a gallon per minute) still holds true, but some engines need more than this. So the fuel delivery specifications also need to be looked up to see if the pump is delivering an adequate supply of fuel to the engine.
The flow meter can be hooked up to the supply line that runs to the fuel rail to measure flow. But Linder says a better method for checking fuel flow and pump capacity is to hook up the flow meter to the return line that runs from the fuel pressure regulator back to the fuel tank. Then check the return flow at idle, 2,500 rpm and 5,000 rpm. The volume of fuel flowing through the return line will drop as engine speed increases because more fuel is flowing through the injectors. Even so, the return flow for a good fuel pump with adequate pumping capacity at 5,000 rpm should still be about half the volume it had at idle (say 0.23 gpm versus 0.46 gpm). If the return flow at 5,000 rpm drops to 10% or less of the idle return flow rate, the fuel pump probably does not have enough reserve capacity to keep up with the engine when the engine is under load. The weak pump will starve the engine for fuel, causing it to misfire and lose power. Get The Right Replacement Pump What’s more, some parts suppliers have over-consolidated their fuel pump lines to reduce the number of SKUs needed to provide broad market coverage. Pump capacities can always be higher than specifications, but should never be lower. So if you get a pump that is flow rated at 0.4 gpm and you install it in a vehicle that requires 0.5 or 0.6 gpm, the pump may supply enough fuel at idle and low rpm, but may starve the engine at higher loads and speeds. Yet it is not a “bad” pump — just an under-rated pump for the application. Fuel Pressure Regulator Problems If fuel pressure is low, disconnect the vacuum hose to the regulator. You should see an increase in pressure if the regulator is not leaking. No change would indicate a bad regulator. Likewise, you can pinch or block the return line temporarily to see if pressure goes up. If it does, it means the regulator is bypassing too much fuel back to the tank and needs to be replaced. Also, check the vacuum hose to the regulator for the presence of fuel inside the hose (there should be none). Fuel in the hose means the diaphragm inside the regulator is leaking and the regulator needs to be replaced. Dirty Injectors It doesn’t take much of a restriction in an injector to lean out the fuel mixture. Only an 8% to 10% restriction in a single fuel injector can be enough to upset the air/fuel mixture and cause a misfire. Gasoline contains waxy compounds that can leave varnish deposits in the injectors when the fuel evaporates. These deposits tend to form after the engine is shut off. Heat from the engine causes residual fuel in the injector tips to evaporate.
On four cylinder engines, the #2 and #3 injectors are in the hottest location and tend to clog up faster than the end injectors on cylinders #1 and #4. The same applies to the injectors in the middle cylinders in six- and eight-cylinder engines. The hotter the location, the more vulnerable the injector is to clogging from heat soak. The cure for dirty injectors is to clean them (on-car, or off-car with special injector cleaning machine), or to replace them if cleaning fails to restore normal flow rate and nozzle pattern. Fuel Injector Electrical Checks One way to check the injectors is with an ohmmeter (key off). Disconnect the wiring connector from each injector, and measure the resistance between the injector’s terminals. Look up the specifications, don’t guess. Some specs may call for 2 to 3 ohms of resistance (typical for “peak and hold” injectors) while others require 12 to 16 ohms of resistance (“high resistance” injectors). The specs are fairly narrow, and with good reason. So if the factory specifications call for 12 to 16 ohms of resistance, and you find several injectors that are only a few ohms higher or lower, the injectors should probably be replaced. And if the injector resistance readings are significantly higher or lower than specifications, there’s no question they need to be replaced. On GM vehicles with Multec injectors, the minimum resistance must be at least 12 ohms. Anything less means the injector is bad and needs to be replaced. Another method for finding weak injectors if you don’t have specs is to measure and compare the resistance of all the injectors. If you find one or two that are noticeably higher or lower than the others, they probably need to be replaced. Injector Scope Checks When the PCM energizes the injector, current starts to flow through the circuit. This causes the waveform on the scope to ramp up. When current reaches about 70% of maximum, the injector usually opens, creating a bump in the pattern. When the PCM opens the ground circuit to turn the injector off, the pattern drops back to zero. On engines that have the low resistance peak-and-hold style injectors, the scope will typically show a pattern with a sharp peak that drops to a plateau until the injector turns off, then it spikes again (two peaks total in the pattern). The peak is typically at 4 amps, and the hold (plateau portion of the pattern) is at 1 amp. On high resistance injectors, a shorted injector that fails to open won’t produce a bump in the pattern. And if you see a sharp vertical rise in the current pattern, it means the injector is bad. A shorted injector can sometimes pull down the PCM driver circuit, preventing other injectors from firing depending on how the PCM driver circuits are configured. On most vehicles, the injectors receive battery voltage when the ignition is on, and the PCM driver circuit provides the ground connection to turn the injectors on and off. If you have a dead injector, therefore, one of the first things to check would be voltage at the injector terminal. If it is less than battery voltage, there may be high resistance in the connector or wiring harness. If more than one injector is getting low voltage, the fault may be a bad injector power supply relay. When the PCM energizes (grounds) the injector circuit, the voltage reading on the supply side should drop to zero as long as the injector is energized. This verifies the PCM ground drive circuit is working and that current is flowing through the injector. When the PCM opens the injector circuit, it creates a momentary voltage spike, which can be seen on an oscilloscope if you hook up the scope to the injector circuit. When the injector pintle closes, it creates a little bump in the scope pattern, which should be consistent from one pulse to the next. If the scope shows multiple bumps or the pattern is changing, it means the injector pintle is sticking, or the injector is dirty. Flow Matching Injectors Subaru Fuel Injector Removal Procedures ![]() to the injector(s).Applicability: All Legacy, Impreza and SVX models. Note: Pliers or any other tools not specified in these instructions should not be used under any circumstances to prevent damage to the fuel injector(s). Fuel Injector Removal:
Fuel Injector Installation:
Courtesy of ALLDATA. |
ELECTRICAL CIRCUIT SHORTS PARASITIC DRAW BATTERY-CAR-REPAIR-HOUSTON,TX
February 1st, 2008
Exterminating Electrical ParasitesBy Glen Beanard, technical contributorAny electrical circuit that is wired “hot at all times” has the potential to become a parasite to the battery. There are some wanted parasites on the vehicle that are necessary to have, and some that are not. We’re going to find out how to “fingerprint” and track down the unwanted ones systematically.A parasitic draw on the battery means that, while the key is in the off position, something is pulling amperage from the battery. Like a glass of water that is slowly sipped on, it will run dry. The symptoms of a parasitic draw, or the customer complaints, can vary depending on the situation. Not every vehicle with a parasitic draw will come towed in with a dead battery. In fact, some may not even require jump starting to bring them in. It just depends on how low the battery is allowed to get before the next start. Intermittent electrical issues like:
When the customer experiences one of these issues that could be caused by a weak battery, possibly from a draw, it can be helpful to perform a full body code scan. Clues can be found in various modules such as a P1000 in the PCM, or “battery voltage low” codes found in air bag, ABS, instrument cluster and various body controller modules. A vehicle with a battery voltage low code stored in any module should be tested for a parasitic draw. Prepping the Patient
Next, set your ammeter up at the easiest to access (and cleanest) battery terminal. Though you could just snatch the cable off and put your ammeter in-line, I suggest some care is taken at this point. With most top post batteries anyway, it is possible to set your ammeter up without breaking the circuit with just a few simple and quick steps.
Step 2: Lift the battery cable up, the ammeter will be completing the circuit if the cable loses contact with the post. Then slide the cable over to the pointed probe that is on the top of the post. Push the eye of the battery cable down so that it is in contact with the battery post. See Photo 3.
Step 4: Pull the battery cable away from the post and drag the pointed probe back to the mounting dent that you made in the top of the battery post. A few twists of the probe into the soft lead post, and the probe will stand up and hold itself in place for testing. See Photo 5.
Ever have an alarm system lock out the starter and find out that the customer has no key fob for it? That’s real fun. Granted, with the nature of the problem that we might be looking for next, we just might wipe OK, so now the ammeter is set up and we have a value showing on the meter. Wow, the meter is showing 0.59 amps. See Photo 6.
If you know the signature amperage, and you’ve narrowed the suspect down, you might be able to prove to yourself what the draw is by manually stimulating a suspect module to see if its signature draw matches what you were hunting for before it “healed” itself. You can’t do that accurately with a test light.
That’s better; some modules have gone to sleep, but still something is sneaking electron sips from the battery and we have its fingerprint. The next step is to isolate the circuit where the offender is hiding. A great way to do this is remove and reinsert underhood fuses one by one while monitoring the draw amperage. However, keep in mind, that while you do this, you will often wake up modules when you reinsert When fuse 1 was pulled, the current dropped to zero. Looking at the fuse explanation chart (Photo 10) for the under Pulling these fuses one at a time in the interior fuse panel hit pay dirt when fuse 3 was removed, the current draw dropped to (nearly) zero once again. See Photo 11. Looking at the fuse chart for the interior fuse panel found three suspects listed. See Photo 12.
With the amplifier disconnected (still shown as connected in Photo 14), the amperage dropped instantly. The cause of this draw was that the amplifier was not going to sleep. A new amplifier fixed this vehicle. Let’s try another one. This is a 2005 Ranger 3.0L. At first, battery draw was 0.34 amps. See Photo 15. After only a few minutes, the draw dropped to the guilty item’s signature draw of 0.14 amps. See Photo 16.
The charts show that fuse to power the “Smart Junction Box” (SJB), which is the interior fuse panel. An SJB is not only a fuse panel, it is also a GEM module (BCM) combined into one unit. This 50A fuse may power a laundry list of items, and the underhood chart is not much help this time since it only says the SJB. So, it’s off to the power distribution charts to see what is powered by that fuse.
The removal and installation of the SJB’s fuse will awaken the supposedly sleeping module. So, the flasher fuse and the amplifier fuses were pulled. The draw remained. Pulling fuse 11 for the SJB’s logic circuitry dropped the ammeter to zero.
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