92 caprice stalling problem

Hello MY caprice stalls out (usually after the engine has reached operating temperature) when ever I put it into gear D OR R. It is not consistent it just does it sometimes, maybe 1 or 2 times a week. And when it stalls out it usually happens repeatedly 2-3 times in a row. It also has died out after a quick de-acceleration. And also the Idle has bounced a few times in park or at a stop. It revs up then almost stalls out. My car has new plugs, cap, rotor, Fuel filter, Air filter, Idle Air Control motor (IAC), PCV valve, and new Intake manifold gasket (It was leaking). Does Anyone Have an Idea? I was thinking about replaceing the EGR valve or EGR solenoid or both. Or the Throttle Position sensor(TP) Hope someone knows. :banghead:

Is the MIL (Service Engine Soon) light on the dashboard lit up, and if so, can you obtain the codes and post them back to us here?

No the MIL light is not lit

Any Ideas???????

Have you tested the EGR?

I personally have not tested it, (I had a mechanic check it & he said Every thing seems fine) I belive the EGR may be the problem but I'm not sure.

Hello MY caprice stalls out (usually after the engine has reached operating temperature) when ever I put it into gear D OR R. It is not consistent it just does it sometimes, maybe 1 or 2 times a week. And when it stalls out it usually happens repeatedly 2-3 times in a row. It also has died out after a quick de-acceleration. And also the Idle has bounced a few times in park or at a stop. It revs up then almost stalls out. My car has new plugs, cap, rotor, Fuel filter, Air filter, Idle Air Control motor (IAC), PCV valve, and new Intake manifold gasket (It was leaking). Does Anyone Have an Idea? I was thinking about replaceing the EGR valve or EGR solenoid or both. Or the Throttle Position sensor(TP) Hope someone knows. :banghead:

Hey bud,

I've had the very same problem recently with my '93 LT1, quick de-celleration stalling, usally, and put an empasis on that, "usally" is caused by the EGR valve not returning to it's seat, or sticking, or a list of other problem's that must be ruled out, one by one, try manually, or with a hand operated vacuum pump, disconnect the vacuum line and cap it off while running, try pulling the EGR valve up with the vacuum from the hand pump, it should, if working properly, lift, and stall or at least stumble the engine at idle, you can do the same by lifting it with your finger but that won't tell you if the EGR diaphram is ruptered like the pump would do, while the car is idling, use your finger to lift the diaphram on the EGR valve itself, it should not stick, or be frozen in place, while doing this the engine should stumble or just die, this is normal operation, EGR is ok.

Now going from open while accelerating to closed at idle and de-cellerating when the engine is at operating temp, this means that the system is operating normally, since there is no codes makes this one a real problem for a home mechanic, a code 32 should show up as a EGR system problem in this case, a scan tool is needed to be absolutly sure what all the sensors are doing while this is happening, to do what you can in the meantime, disconnect the negitive terminal on your battery first before doing anything electrical to protect the system from a disaster while your working on it.

Before you disconnect the battery, Check the EGR as above, then go over all the vacuum lines, making sure there is no dry rot, or cracking in the hard plastic lines, battery terminal off, remove the IAC and use some quality carb cleaner to blast out the valve seat, clean the port as best you can without damaging the seat, now, also blast the throttle plates, open and shut, empahsis on the rods the the plates are screwed on to, checking them also for loose or worn blade shaft's, then taking your IAC, spray the pintle cleaning it as best you can , "do not allow it to soak in carb cleaner" as it is a sensitive electrical component, before you re-install the IAC, gently wiggle the pintle from side to side using a slight pressure to depress the pintle as it will probably be fully extended, and replacing it without doing this can destroy it.

Test your EGR solenoid for resistance in OHM's, using a digital multi-tester, it's a cheap tool, usally around $30 for a good one, to rule it out, the value is easily availble in your manual, as you become used to using this tool, it will become invaluble as a tester on all your sensors and many other things, well worth the cash.

A good manual is also a must have, it can be dull reading but if you want to find your problem, all the resistance values of your sensors, trouble code listings, ect, are in there, without draining your wallet, some things are nessesary.

Replace the negative terminal after all is gone over, everything is routed and connected properly as best you can do, start your engine and let it rev at approxomatly 2000 rpm for 15 seconds or so at operating temp, to allow the ecm to "re-learn it's idle setting", you will need to hold this with your foot until the ecm takes over, then if all goes well, turn off the ignition for a couple seconds, restart, and the IAC should be set along with all the other sensors in tandem as they should be, if not, deeper diagnostic's are needed.

Hopefully this helps you, as more sensor testing and or the scan tool is needed after this point, 80% of these problems are related to the simple things like vacuum leaks, incorrecly connected wiring, or shorts in the same, btw my problem was solved by replacing a cracked hard plastic vacuum line that at first "looked" ok.

Thanks for all the info... As soon as the weather gets better I'll give it a shot. Thanks again!!!!!!!!!

Update: I have now taken my car to 3 mechanics one of which is a chevy dealer. No one could figure it out. I have now replaced the Ignition control module, the Ignition coil, the TPS throttle position sensor and the MAP sensor. Nothing helped except for the ignition coil which now keeps the car running when it would usually die out. However it still dies out on occasion usually below 6mph. The car now runs fine cold, but at operating temp at 6-14mph if i accelerate about 2mph then let off the car stumbles and tries to die out. Now I'm thinking of replacing the EGR valve or the distributor or maybe the EGR solenoid. Anyone know or have a better Guess?

I have the same problem and I could not se anything wrong with the ERG valve, I thougt it could be the fuel pump, am I wrong, what do you think.

or the fuel filter

If you have the same problem change Your fuel filter it is cheap and easy to replace I changed mine but did not help the problem. It is reccommended every other year. My fuel pump is fine and was tested @13 psi, usually the fuel pump is dead or fine, rarely are they barely working. I know my problem is not with fuel delivery.

Changing the EGR valve is easy and not expensive. Better to try something relatively inexpensive yourself before spending bigger bucks seeing a mechanic, most of which are glorified parts changers.

It might be caked up below the valve in the manifold, so be prepared to dig out some carbon. You might have to hit the bolts with some spray lube in advance to make them come out easier. I always replace these with stainless steel bolts and never seize.

Good luck, Bob