When I first start engine it will rev between 600 and 1100 rpm as if it constantly searching, I've been told it could be a intake manifold gasket or hose. This advise was given to me by a non-vette owner and then I found out about your forum. Please give me your opinion. If you agree, how many gaskets are involved, where can I purchase a full set (might as well do them all) and is this a project that a non gear head should attempt?

Thanks

 

Barry,
Try this forum; they specialize in our x-fires..might be some other issues related to TBI
http://www.crossfire.homeip.net/cftest/

 

you more than likely have a vaccum leak. the crossfire is prone to vaccum leaks and the leaks reak havic on the system causing unstable idle. The intake manifold is gasket with RTV sealant only. Check your vaccum hoses for cracks, splits and pin hole leaks. Make sure your check valve has not been pulled out. Do your head lights raise and lower? Also check and make sure your EGR valve is not clogged and is functioning correctly. The throttle bodies may be worn causing a small vaccum leak and if the plates have any play at all it will cause them to flutter which will also give you unstable idle. The coolant temp sensor (CTS) located above your water pump on the front of the block could need replacing it sends a lot of critical info to the computer that will effect how your car runs. Buy a shop manual for your car. I am assuming it is an 82. You can find them on ebay all day long usually. also take a look at this link it is very usefull:

http://www.corvettefever.com/techart...ing/index.html

My 82 idled at 1500 rpm when I bought it. I changed the CTS sensor, the O2 sensor, cleaned the intake and throttle bodies, changed the fuel filter, fuel pump and tuned the car using the method in the above link. Now my car idles at 1200 rpm at initial cold start up and drops to 700 rpm in park once the car warms up and in gear the car idles at 600-650. My car has slightly worn throttle bodies so my idle does fluctuate a little. All in all my car is very close to being right and runs a lot better.

Good luck

 

It will probably be one of 3 things.1) Vaccum leak as you suspect. 2) fuel pump. 3) coolant temp sensor.

On cold start the computer takes a reading from 2 things. Coolant sensor and MAP sensor. If its searching for an idle from the get go its one of the three things I out lined above.

I would change the coolant sensor first. Its cheap and easy to do. Make sure your rad is full.

If the temp sensor doesn't do it. Change the intake gasket. For the time being you can check the bolts on the intake plate. make sure they are tight. They tend to loosen.

If the CTS and intake gasket doesn't do it consider the fuel pump. If it is the fuel pump you should have other symtoms. On excelleration the car should hesitate or rpms should hang....feels like its getting stuck at a point.

Jim

 

 

I spent a lot of time on the crossfire forum when I had my 84, good group. Does an 82 have an IAC?