Warranty Won’t Cover Costly Repair
Question: Since the onset of cold weather, I have experienced starting problems with my four-cylinder Toyota Camry. When the engine is cold, the gas pedal seems to stick. I thought all I needed was some lubricant on the throttle linkage, but the dealer said it was a carbon buildup in the fuel injection throttle body. I was told it would have to be removed and boiled out, a costly service not covered by my warranty. Is this a rip-off?
--J. N. M.
Answer: It’s not a rip-off, but Toyota’s unwillingness to cover it under warranty is in a gray area. Because this problem affects the engine emissions and is caused by emissions, it could be covered under the car’s five-year warranty on the emissions system.
But Toyota has obviously tried to sidestep the problem by saying only the three-year standard drive train warranty applies. If you yell loud enough, you might get the dealership or a Toyota representative to cover the repair under the five-year warranty.
No doubt, however, the problem and the diagnosis are valid. The fuel injection system has a part called the throttle body, which regulates the intake of air with a butterfly valve, not unlike the choke plate on a carburetor.
The fuel injection system also has a feature that recirculates crankcase gases with the fresh air taken into the system, something called positive crankcase ventilation.
The port where the dirty crankcase gas enters the throttle body is very near the butterfly valve, and an oily buildup has probably caused the butterfly valve to stick. It seems that the throttle linkage is sticking, but the problem is a little more complex.
You might avoid this problem by more frequent oil changes and by using a better brand of gasoline to to keep your engine running cleaner.
Q: I recently had to take my 1978 Cadillac Sedan DeVille in for a smog check. Before the test, I pulled the plugs and regapped them from around .06 inches to .035 inches. The car runs beautifully and passed the test.
But I am wondering whether the different gap could damage my engine or affect my gas mileage? --H. L. C.
A: You have the wrong gap on your plugs and at least theoretically you are degrading your fuel economy, increasing your output of engine emissions and running the risk of fouling your spark plugs.
A spark plug gap should be as wide as possible to allow the ignition spark to reach as large a volume of fuel as possible. The limitation to ever larger gaps is that the engine would need an inordinate amount of electrical energy as the gap gets wider and wider.
In cars going back to the early 1970s, when ignition systems had points and condensers, gaps were routinely set at .035. Electronic ignition systems that appeared in the 1970s meant that gaps could get much larger. Ford and General Motors cars have plugs with gaps that range from .044 to .08.
The spark plugs with the larger gaps are not the same plug with a different adjustment. If you take a small-gap plug and attempt to set it at a large gap, the side electrode will be at an angle to the center electrode and cause uneven wear.
Conversely, you have apparently taken a large-gap spark plug and set it at a small gap, also resulting in an abnormal angle between the two electrodes. You could very well get premature wear on the plug and eventual misfiring in the engine. Although the car seems to run fine, you will eventually have trouble for your tampering.
