Dirty Fuel-Injected Engine May Prevent Smooth Start
Question: My 1987 Ford Taurus station wagon has recently begun to die when I try to start it up in the morning. It has a fuel-injected engine with 41,000 miles on it. Please tell me what is the proper tuneup for a fuel-injected engine? --L.B.K.
Answer: Your problem is probably caused by a dirty fuel-injection system, a common problem in mid-1980s cars that is becoming less frequent with newer designs.
The fuel-injection system has tiny injectors, nozzles that squirt the correct amount of fuel for each cylinder into the intake manifold. The problem occurs after the engine has been shut off and the temperature begins to rise, something called heat soak.
The injector still has a minute amount of fuel in it that turns into a resin by the high heat. After a period of time, the resin builds up and restricts the flow of fuel into one or more cylinders.
In severe cases, the injectors must be replaced, but often a chemical cleaning will solve the problem. A mechanic can route a cleaning fluid through the injectors while the engine is running.
As part of a regular maintenance program, you can also use injection cleaners sold at retail stores. One good product that I have mentioned in the past is Chevron’s Clean Up with Techron.
Engineers have solved some of the problems with clogged fuel injectors on newer models. On the new Ford engines, for example, the injector has a special clean-up system constructed of a metering plate and four tiny holes that force fuel through the injector at very high pressure to clean off any buildup.
Q: The windows on our new Toyota Cressida keep fogging up all the time. The only way we can avoid this is to turn on the air conditioning and roll down the windows. What’s the problem? --J.W.S.
A: You’re probably not using the pricey climate control system on your car properly. On the automatic climate system, the air conditioning compressor turns on whenever the control is set on defrost or on air conditioning.
The compressor will dehumidify the air and eliminate the fog. So, try setting the controls on defrost and on outside air, rather than recirculation.
Q: Please explain if it is ever advisable to add STP to an old car engine using straight 30-weight oil. The engine, which has about 100,000 miles on it, isn’t burning oil. --J.G.
A: STP is a treatment that increases the viscosity or thickness of your motor oil by about 5 to 10 SAE weight, depending on the capacity of your engine’s lubrication system. Using a heavier oil sometimes can help reduce oil consumption in an extremely worn engine. You can achieve about the same effect as STP provides by selecting a heavier weight oil, such as SAE 40.
A recent column advised the owner of a 1978 Toyota Celica that her clutch or transmission may need repair because she had difficulty shifting into first gear.
Another reader with the same problem reports that after spending considerable money on the problem, he discovered on his own that the difficulty was caused by a template on the floor that guides the shifting lever. A flange fell out of place because of a loose screw, blocking the shift lever. With no degree in rocket science, he fixed it in 10 minutes.
