so i conducted a little search and i still can't figure out a thing about my EGR system, can anybody show me a guiding picture or something, like i said it's a 90' k5.

yarin.

 

i know this is kind of foolish to suggest, but worth a shot. have you checked all the electrical for any kind of nicks or burs? maybe you have an intermittent short somewhere. i wish i could help with the EGR, but my k5 is a 79, very few (if any) components are computer controlled.

 

i might be way off base here .....but the transmission has a lock up converter ....if its locking up at low rpms it could cause the engine to stall....but doesnt make sense for the highway speed driving as it should be locked anyways.

 

check fuel filter also the egr is a funny looking thing that bolts directly to the intake manifold has one vacuum line going top it. it is mounted slightle behind the throttler body on the passenger side

 

You try changing your coolant temp sensor. The computer uses it to base most of the engine controls on it. Had the same problem that you have now. cheap fix.