good evening,
I have a 94 gmc jimmy 4x4 4.3 auto I am have an issue that i thought i had fixed I had it problems with hesitation hard starting then one morning I went out to start it and nothing just cranked had spark and fuel pump worked. So i did some research found out that the cpi had issues with this truck. so i put a new spider and new feed lines in put it all back together started it a presto it was running good still had a high idle issue but it ran so when to school this morning came out to go home and bam it would not start so i towed it home
started checking things out to the ignition module had it tested it was fine checked pickup coil it ohmed OK but the wire's were cracked and had bear spots so i just got a rebuilt distributor put it all back together and no start condition still so i gave it a shot of ether and it started and ran but still have that high idle but it stated to stall and just before it died it caught itself and ran but the idle jumped up high and never came down
things changed
fuel tank (had pin holes in it)
fuel pump(twice)
fuel filter
spider
distributor(cap & rotor as well)
checked fuel pump pressure KOEO 60 Psi when pump turned off pressure drop immediately but my gauge leaks fuel have to fix it and try again
truck running pressure it at 55psi.
im at a loss still having a fuel issue i believe any suggestions or advice and sorry for the long post

 

sounds fuel pump to me,although its been done twice. Is it a aftermarket $40 pump? these blazers hate em! thing is online you can get a official ac delco pump for the same cost.

 

high idle vac leak or isc motor stuck

 

Check the codes.