Engine Performance problem
1999 Toyota Camry 4 cyl Front Wheel Drive Automatic 70000 miles
I have a 1999 Toyota Camry 4 cyl with 70,000 miles on it. On really hot days when I stop at a light, the idle can suddenly drop and bounce suddenly. During stop and go driving in summer I have never seen the temp gauge go beyond half way. On a hot day (above 95 deg) the temp gauge can hit the half way mark within a mile or two of in town driving. Soon after it reaches half way mark the idle speed at a light will usually drop to 600 RPM. Usually after the first time I noticed the rpm at 600 at a stop, at anytime while stopped the idle can suddenly drop to 400 and bounce back up to 1000. It feels like the engine is about to quit and the idle is real rough. At a stop when this occurs, I shift into neutral or park and accelerate slightly to keep the rpms above 600 rpm. If I use the conditioner the idle problem will show up sooner. During the idle problem the check engine light never comes on. Also after the idle problem first appears while driving at a stop, at any time while driving I can lose power during acceleration. It kind of has symptoms of vapor lock but the fuel filter under the hood is always cool enough to touch. I have taken it to shops and they checked the computer, fuel pressure, etc. And couldn't find anything wrong. This problem never occurs in winter or when the temp gauge is below the half way mark. I had the EGR replaced, new plugs, cleaned the throttle body and had the injectors flushed. This didn't solve the problem.
This has been happening the last three summers. Any ideas what could be causing the problem and how to resolve it.
Wednesday, June 25th, 2008 AT 3:02 PM