Hello All,

I have been reading about what might be the problem on this site but I cannot figure it out at all. My car is an all original 93 Bonneville that has a wicked idle upon start-up. It will do it for about 1-3 minutes and then it will go away. My mom gave me the car so I know that it has been babied, I made her for the most part. It has 150,000 miles on it and runs great except for this problem. I have talked with a few mechanic friends and they are telling me that these cars are notorious for having the fuel pressure regulator go out on them, but that seems a little strange to me. I have also read that it might be something to do with the throttle body. I was going to take it off and look at it but that particular area looks to be a big mess and without step by step directions I am not going to tear into it. Does anyone know what might be the problem with it? I know that it isnt the fuel pump because when you give it gas the car will actually rev and also once you leave it for a short time it does not happen again until the car has been sitting for a while. Any help on this would be greatly appreciated. Thanks.

How high is the idle upon startup?

It will bounce from 1200 down to almost stall, which it actually did this morning, and then back up again.

Use the procedure in Techinfo to extract any codes. All you need is a paperclip.

Does the ECM pull codes without flashing the SES? I have not had a code on this problem at all.

I am not familar with these cars at all, I delt with nothing but my Camaro and now it is time to branch out. These cars run an OBD1 correct? If so jumping the terminals will just pull stored codes and like I said the SES has not been tripped at all.

Not all stored codes will set the SES.

I will pull those out tonight when I am by the car and put it here.

Edit: It is a good thing I looked out there for the code retrieval, it is the same as my Camaro and the codes are very simliar as the Camaro. If there is actually a code it will at least be easy to diagnose it. Thanks.

93 is the last year that feature worked on the Bonnevilles. This is very basic. Further troubleshooting will require a scantool to do it right. Check Techinfo for a scantool registry. We may very well have someone near you with one.

I know most GM cars will idle high upon startup, like even up to 1500 sometimes. You need to see what your computer is requesting the idle to be set at.