1997 2.2 Cavalier Starting and Idling Problems

I've got a 1997 Cavalier with a 2.2.
About a month ago, the car started to idle rough and and became hard to start, or stay running at an idle. Would run good once going down the road, or highway. It would tend to start better when it was cold out, here in Wisconsin.


Replacing the wires and spark plugs seemed to help a little, if any.

I also changed the coolant sensor and the 02 sensor, at the same time.

I noticed that it seems to surge up and down at a idle and spew some black smoke out of the exhaust like it is running rich. The plugs are also black like it is running way to rich.

It has good power going down the road.

It will surge up and down if you hold the throttle down up until about 1500rpm's at which point it seems to run steady.

Any ideas?

Perhaps the Throttle Position Sensor?

Does that cause it to run rich?

It turned out it was a bad fuel pressure regulator. The codes came up with an 02sensor, coolant temp sensor, and a Throttle Position Sensor.

I replaced both 02 sensors, the coolant temperature sensor and the fuel pressure regulator, and it seems allright now.

I also changed the plug wires and the plugs.

I knew something was wrong when it wouldn't start at all one day in the garage and I took out the plugs and they were soaked with gas. So I decided I would turn the car over with the plugs out. When I did that tons of gas shot out of all the plug holes. So when I pulled the vacuum line off the Fuel Pressure Regulator it had gas in it. So I realized then the diapraghm in the regulator had broke and was allowing gas to get sucked into the throttle body through the vacuum line.

Problem solved.

For now at least. LOL

I hope this helps some other poor sap out in the future. LOL