Date: Sun, 16 Nov 1997
Glenn,
I've got two more questions or problems...
1. During the summertime, I usually start the car, maybe idle for 20 seconds and then just drive off. Since L.A. has been getting much colder now, I realized when I drive the car off in the morning with 20 seconds idling, I seem to lose power occasionally when I'm accelerating. It's like when I press on the accelerator pedal, the car would accelerate one second, then the car shakes (read: decelerate) a bit from the engine losing power, then I get power again. It resembles a car about to stall (vigorous shaking) from an inexperienced stick-shift driver.
This occurs only during the first 5 minutes. Afterwards, the engine is fine, runs smoothly. I suspect that it is NOT the clutch because as I was idling at a stoplight, the engine wanted to stall, too. Do you think it's just the weather and I need to warm the car up in the morning? How long do you warm up your car? Or do you think it has something to do with the fuel injection? Or is it the clutch?
2. The other question is about nauseating fumes inside the car. Do these fumes usually originate from a bad exhaust system? Mine is really rusty but no noticeable holes yet. Or is this just typical of an engine that's over 26 years old with 95,000 miles on the clock? Do you think it's time to have the engine looked at in detail?
Thanks for your help!
Oliver
Oliver -
I usually warm up the car for twenty or thirty seconds before putting it in gear, and I drive it very lightly until the temperature gauge reads normal. If the weather is very cold (below freezing), I let it warm up for a few minutes.
The problem you're experiencing is often called hesitation, and there are various causes for it. Since you are noticing it now that the weather is cold, and since you say it goes away when the engine is warmed up, I would first suspect an air leak in the induction system, possibly bad fuel injector seals. There is a story about fixing this on my web page under "Fuel System." Before you go to this trouble, be sure all hoses and plugs attached to the intake manifold are secure and in good condition, and do the same with the manifold and its gasket.
Other possible causes are ignition timing or distributor contact points out of adjustment, or maybe the engine air filter is very dirty and not letting enough air through. Although ignition problems normally affect engine performance at any temperature, cold weather can aggravate them.
Nauseating fumes are almost always caused by exhaust leaks. This could be hazardous, so you should check into it soon. With the engine running, look and listen carefully where the exhaust manifold bolts up to the engine, and especially check the headpipes where they bolt to the manifold. Sometimes these need to be tightened and sometimes they need new gaskets. From there, follow the exhaust system back and check every place where the exhaust pipes are joined together. Sometimes it is possible to see exhaust fumes leaking by placing a light behind the area you suspect. Of course, the exhaust system is extremely hot with the engine running, so be careful.
Another place to check is the trunk. If the rubber trunk seal is badly decomposed, exhaust fumes may seep into the trunk and from there enter the cabin.
Crankcase fumes are normally fed back into the engine via the PCV system. Check the hose leading to the oil filler cap to be sure it is in good condition and securely connected. Do the same with the hose leading to the flame trap (located forward of the distributor).
If the fumes smell like gasoline, check the fuel lines, especially the hoses connecting the injectors to the distribution pipe atop the engine.
Hope this helps. -Glenn.