Ok! I have a 1993 chevy caprice classic.I believe it was a police intercepter.Runs great at 60 to 100 plus mph.When I slow down to make an exit it sometimes stalls. When driving in the city it stalls out at red lights at times, especially with a/c on.

Jeff,

What engine size?

We have a very similar posting already in progress. We want to handle yours separately but I would like you to read this other posting to see if there is info that is helpful to you. If you are on the home page you can scroll down and click "all questions and answers". You can then scroll down and continue viewing other pages by clicking the page number at the bottom. It is currently at the bottom of page two but this will change. PLEASE DO NOT POST ON THE OTHER POSTING! Post back here with any other questions or info. If you have a problem finding it tell me and I will put it back closer to the top. We'll be glad to help.

I'm gonna try and put everyone on the same page since there are three separate postings for this vehicle.

Jeff stated "93 chevy-cont. It's a 5.0 w/air rail going into each cylinder. I changed out fuel filter(nasty),egr part,tune up 3 yrs ago.runs great otherwise."

And

"93 chevy-cont. new air filter,does'nt burn oil,gets about 28 highway-21 city(mpg).Would like to fix,or maby trade out for car for wife."

Sounds like the vehicle is in pretty good working order. Although there are many things that should be checked the first thing that comes to mind is a dirty throttle body and IAC valve.

I told you that there was another user with a similar problem. I'm gonna drag the info from that posting over to this one...

I have a 1993 chevy caprice classic. It stalls at times when I come to a stop, especially while having the a/c on. For years it did it once in a while, now it's doing it alot. can someone help?

Submitted by jeff zentmyer Fri 08/05/2011

Submitted by drivability on Fri, 08/05/2011 - 01:12.

There are a number of possible problems. One of the most common is a dirty throttle body and IAC (idle air control) valve. There are other things you can check for such as vacuum, ignition, fuel, compression, charging system, A/C and exhaust problems. Have you checked the computer for codes (if so what are they)?
Is the check engine light on?
What is the engine size?
Tell us if there have been any repairs done lately (if so what?).
Tell us what you have checked already (if anything).
Please post your response back here. We'll be glad to help.

Submitted by Big Block 409 on Fri, 08/05/2011 - 05:20.

In addition to what's already been posted you should throughly clean out the throttle body and replace the air and fuel filters. You should also try a few applications of "Sea Foam". Don't just pour the sea foam into the fuel tank. Read the instructions on the can, and introduce the sea foam into the engine through a vacuum port.

Submitted by drivability on Fri, 08/05/2011 - 15:20.

If and when you clean the throttle body, it is important that you do as Big Block said (thoroughly clean the throttle body). There are three ports on top of the throttle body. 2 large ports (for the main air intake) and 1 small port (for the IAC). Clean all three. If there is any oil in the throttle body, you might want to check for vacuum at the PCV valve with the engine running. If there is no vacuum there (a common problem) and there is not a vacuum leak, you might want to remove the throttle body and clean the ports underneath. All of this is very easy to do and pretty cheap. If you need to remove the throttle body you should be able to get a base gasket at the local parts store. The seafoam is great stuff. If you introduce it through a vacuum line, just make sure the engine doesn' stall. It is not hard to perform this service but you don't want too much cleaner at one time. It can hydraulically lock the engine and cause damage.

Hope this info helps. Please post back here. We'll be glad to answer anymore questions you may have.

Mileage on car?
Last time fuel filter was replaced?
Last time fuel pump was replaced?

Attach a fuel pressure gauge to the fuel rail and drive with the gauge attached. Drive at different speeds and different engine loads. You gotta know that regardless of the speed and engine load that fuel PSI has to remain constant. If while drivin you see the needle on the fuel gauge fluctuating you know that the fuel pump is breakin up.