Questions and Answers

Chevy Cavalier Z24 No Hot Restart Q. Hi, We have a 1991 Chevy Cavalier Z24 with a 3.1 liter MFI OHV with manual transmission. 276,000, ABS brakes and P/S. The engine starts fine when cold. It idles a little high at first, as it should, until it warms up and then drops down to normal idle, approximately 1,000 RPM. I can drive the car around all day, without overheating, or any kind of fluctuation in the idle speed when parked.

The engine doesn't sputter or gasp/lurch in any way when accelerating or decelerating. If the car is shut off, when at normal operating temperature, and you try to restart it within a few minutes, the car turns over normally but won't start.

If we wait for the engine to cool down to approximately 40°C on the temperature gauge, the car will start. It seems like the warmer the engine is, the rougher the start, if it will start at all. With summer approaching, it's taking longer and longer for the engine to cool enough to start properly.

A few months ago, before this problem started, I put Penzoil fuel injector/fuel system cleaner additive in the gas tank and did a minor tune-up before taking the car through a government emissions check, which it just barely failed, due to an unacceptable hydrocarbon level.

I filled up with premium, high octane, 10% ethanol blended gas at Mohawk and took it through again and it passed with acceptable emissions.

Shortly after, on a warm sunny day, the engine failed to start when warm, for the first time. Could these be related/did I maybe damage or disturb something with the additive or high octane, or is it just coincidence because of the warmer weather?

Thanks in advance, for any help or suggestions,
Sean and Danielle

A. You need to find out what is missing when it won't start. Maybe the fuel pressure isn't enough to fire it or the ignition is cutting out. You need a fuel pressure gauge installed & maybe even a scan tool to look at all the data when it won't start. Possible a bad Crank Angle Sensor or fuel pump.