You need to answer most of the questions above before I can help any more. Otherwise it's all speculation.

 

When I turn the key to on the check engine light comes on so I know it works. When I start the car the check engine light goes out. However, while I'm trying to keep it running at about 2500rpm the check engine light intermittently flashes. It will come on for a fraction of a second and go out. The car will not idle.

 

You need to check for stored codes. Do you know how? The connector is under the ashtray. Bend a paper clip into a "U". Insert the paper clip into holes A and B. turn the key to "on". Have a pen and paper.Watch the engine light.

It will flash 12. 12 is one flash followed by a pause then two quicker flashes. It will pause and flash 12 two more times. So in total it flashes 12 three times. Stored codes come after that. The number coup be as high as 55. When done it will flash 12 three more times.

So let's say the codes 22 and 43 are stored. It will flash as follows:

12 12 12 22 43 12 12 12

See the three 12's saying start, codes in the middle and 12 three more times to signal end.

You can't mess it up. If you lose count just turn the ignition off and start over.

Grab the codes and report back.

If it flashes 12 six times that means no codes are stored.

 

Looking at the plug under the ash tray there are two rows of six holes. The upper row only has a pin in the right one while the bottom row has all six pins. I used the first two holes on the left side in the bottom row. The check engine light flashes 12, nothing else. I actually let it flash 36 times and 12 is the only number that comes up. I actually have the GM code reader, which obviously is nothing more than a paper clip in a plastic housing but I couldn't find it. So, if no codes are up and it's running so very rich I'm still thinking it's a bad vacuum leak such as intake manifold. Any guesses?

 

Thats a good sign...no codes.

Changing the lid gasket is the very first thing I did. It goes and will create all kinds of problems. I suggest you do the same. Vac leaks are real bad for these engines. The EGR could also be leaking...source of another maassive leak.

Check the bolts on the lid are they loose? Tighten them down a bit.

If its not a vaccum leak only a couple of things could cause the problem you are having. As mentioned the CTS could be bad, The TPS maybe out of adjustment. The timing maybe out. the 02 may be bad.

I suspect its one of the above and something else. You are getting a engine light flash wich suggests something else....like maybe the rotor in the distributor. It could also be a flat spot on the TPS.

Check the TPS. Its easy to do. See if its set to .525 and as you move the arm climbs smoothly to 4.5 volts. With a meter set to the third decimal point probe wires marked A and B on the TPS with the ignition on. If you don't have a jumper use two paper clips, tap one to the end of each meter wire, insert the end of the paper clips into the spots marked A and B on the TPS plug. Get as close to .525 as possible, max variance of .08. Eliminate the TPS as the problem. Hopefully your timing is on or close to right.

You can also try starting the car with the CTS unplugged and see if it makes a difference.

 

By lid gasket are you referring to the plate that the TBI's are bolted to? If I've got to remove the plate and TBI's I might just as well change the intake manifold gasket if I'm in that far.

I unplugged the temp sensor and it didn't seem to make any difference. I revved it good a few times but I only let it run a minute or less because I'm trying not to foul the new plugs with fuel.

 

CTS is the one at the front.

Don't remove the intake. Just the TBI plate.Yes its the plate the TBI's sit on.Clean all the carbon out under there once you are in.

The TBI plate comes up with the TBI's on it. Just disconnect everything.

If you want to change the gaskets at the base of the TBI's undo the bolts on both. Lift them up together...the one linkage that connects the two does not come off easily. You will see what I mean.

Get the proper gaskets. No silicon!

Jim

 

The big gasket is the one I'm talking about.

https://pontiworld.com.au/usgmsp/pop...e.php?pID=8216

 

Thanks. That's what I thought it was. I just figured that while that plate was off it wouldn't be that much more work to change the intake manifold gasket as well.

 

Your looking at 1 1/2 hours to change the gasket.

Unless you have other problems I'd leave the manifold alone

 

It couldn't be as bad as when I changed the intake gasket on my 90 Corvette.

 

change the sensor first .you can check the gasket with starter fluid .i would find a leak before i changed the gasket.

 

Much much easier.

After thought unplug the TPS and see if it starts and idles in limp mode.

 

I thought I'd share a funny one today. I had about 5 extra minutes this afternoon before I left for work so I thought I'd start the 82 Corvette to see if I could get it to idle even for a minute. I started it up, revved it a couple of times and suddenly it cleared right up. Smoothed right out and the black smoke started to diminish. I looked at the two TBI's and only a little fuel was coming out. Wow I thought. Then it quit running and I realized it had just run out of gas. So, as it ran out of gas it got real lean and briefly it ran ok.

Maybe this weekend I'll get to pull the plate with the TBI's on it and replace the gasket.

 

Maybe it's bad gas. If you were that low on fuel chances are you were sucking up water. Try fresh gas and a can of seafoam. While you are at it pour a can of seefoam into the TBI's while it's running.

 

Well whatever happened??

 

I have not had a chance to get back to it, I've been too busy with my 1001 other projects and jobs.

 

I hear ya but let us know. Interesting thread...Especially when you own a crossfire.

 

My 1972 is the easiest, points distributor, carb, no electronics, then came the 1990 with all electronic, and now the infamous Crossfire.

 

When a CFI engine is unplugged it takes a few cycles on the engine for the ECM to adjust. My 82 has had very minor common problem that were minor with well over a100,000 miles that were simple to fix with basic fuel injection knowledge. And the felpro plenum gasket NEEDS TO BE REPLACED!!! It was just silicon from the factory.