Q: My wife drives a 1995 Toyota Camry (four-cylinder engine) with approximately 96,000 miles. About a month ago she drove the car for about 20 minutes, the car then sat for an hour. It started right up, she drove for about five minutes, then stopped for a traffic light. When the light turned green, she stepped on the gas and nothing happened. After a short pause, the car finally started to go. She made it home with no problems. I changed the air filter two days later, thinking it might be a hesitation problem. Over a couple of weeks the car acted up three more times with the same symptoms — hesitating when she stepped on the gas. None of the dashboard warning lights came on. Finally, the car stalled while she was waiting at a red light. She was able to get it started and drive home. The car has now been at the dealer for three days and, being unable to duplicate the problem, they have not been able to fix the car. What would cause this? Is there a sticking valve someplace that needs to be lubricated? Your thoughts, please.
A: A few diagnostic techniques to think about would be to pull the timing belt cover and check for a loose timing belt. If that checks out good, then on to the next test, which is a little bit tricky but not that hard for a do-it-yourself guy. Locate the EGR valve. There will be a single vacuum hose going to it. Unplug the vacuum hose, then put a golf tee in it. Drive the car for a few weeks. If the problem disappears, you simply need a new EGR vacuum regulator.
If all the above checks out, then pull the fuel filter and look for pieces of plastic in it. Plastic would indicate that the fuel tank lining is falling apart due to ethanol gas. It’s as simple as that.