part by part

I bought a 1992 jimmy 4.3 tb vin z 4x4 it has 150k on it.
it stalls at idle but runs perfect(for high rpm) if you give it a lot of gas.
I've replaced the spark plugs*, spark plug wires*, distributor cap*, (yes the firing order is right I checked and rechecked it many times 165432 clock wise), rotor*, fuel filter, fuel regulator*, both temp sensors*, tps, swapped iac motors with one I know works but it still has the same problem!!!!!:banghead:
please someone help! I've searched all post with this problem and tried most but am ready to push this thing off a cliff.
I noticed the iac pindle is about and inch away from being seated when I took the tb off, is that normal? and inside the distributor cap its building up copper to the side of the pins, can this be a simple timing issue? also when I took the distributor cap off it was really rusty inside. it looks like it has a new iac motor and ignition control module.

please help I'm going insane trying all these things!

all parts with an * after it definitely needed to be replaced.

I'm not sure if you have one, but when I had the exact problem on my 91 Camaro it was the ignition pick-up.

it has a Distributor Pick-Up this the same thing?

here is a link to a picture...

http://partimages.genpt.com/partimages/512616.jpg

or

http://partimages.genpt.com/partimages/50867.jpg

thanks for the quick reply!

yep, thats it, after much headache thats what solved my problem

EGR valve stuck open would cause this. Clean it , replace it or block it off just for testing purpose.

sorry I haven't posted back until now.

when I went to replace the distributor pickup the plate it sat on broke into 10 or 20 pieces(because it was rusted through for some reason) so I replaced the whole distributor and it runs like a top now!!!

thanks for all the suggestions!