My engine stalls at idle?

It sounds like you have a vacuum leak but to be sure lets run down these guides

https://www.2carpros.com/articles/stall-at-idle

and

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Please run down these guides and report back.

You are welcome

Clean and test the idle air control valve and also the EGR valve-CEL on?

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

You can bring it in to an auto parts store and have the computer checked out or the dealership-

This sounds like you have a vacuum leak or the IAC valve is gummed up or not working here are two guides to help you see whats going on and fix the problem.

https://www.2carpros.com/articles/stall-at-idle

Please run down this guide and report back

Cheers

Welcome to 2CarPros.

When it starts, are you able to keep it running if you hit the throttle?

Take a look through this link and see if anything helps. Also, let me know if anything else was done. For example, was fuel pressure tested, have you checked for vacuum leaks, has the catalytic converter been checked for plugging, and so on. Anything you can think of that may help.

https://www.2carpros.com/articles/stall-at-idle

Let me know.

Joe

Hello jeepmanjr

On Behalf of 2carpros, I wish you happy new year.

When an engine suddenly quits running, but then starts again and runs few seconds and quits running again ,the cause may be the loss of an important sensor signal such as the ignition trigger signal (engines with distributors)
Older GM HEI ignition modules also were prone to this disorder - especially if someone replaced the module in the distributor and forgot to apply the heat sink grease underneath to prevent the module from overheating.
your engine is a 4.3 L I believe and please correct me if I'm wrong so we can be on the right path.

Here is what we can do
start with ignition coil.

Disconnect the distributor lead and wiring from the coil.

Set the ohmmeter to the HIGH scale, then connect it to the coil as shown in Step 1 of the illustration. The reading should be infinite. If not, verify a proper test connection to be assured of a true test result and if still not infinite, replace the coil.

Set the ohmmeter to the LOW scale, then connect it as shown in Step 2 of the illustration. The reading should be very low or zero. If not, verify a proper test connection and replace the coil.

Set the ohmmeter on the HIGH scale, then connect it to the coil as shown in Step 3 of the illustration. The ohmmeter should NOT read infinite. If it does, verify the connection and replace the coil.

Reconnect the distributor lead and wiring to the coil.

print this for your diagnosis.

pick up coil testing

Disconnect the negative battery cable.

Remove the distributor cap and disconnect the pick-up coil connector from the module

Connect an ohmmeter to either pick-up coil lead and the housing as shown in Step 1 of the illustration. The reading should NOT be infinite. If the reading is infinite, replace the coil.

Connect an ohmmeter to both pick-up coil leads as shown in step 2 of the illustration. Flex the wires by hand at the coil and the connector to locate an intermittent opens.

The ohmmeter should read a constant number in the 500-1500- range. If not, replace the pick-up coil.

print this for your diagnosis

If you "pump" the throttle as you put the trans in drive, does the engine still die? Does the engine start and idle normally before you put it in drive?
My first thought is with the idle speed control unit(ISC). This little valve is supposed to compensate for added engine loads such as power steering, AC and transmission. You may want to have this unit checked. Hope this helps.