For the ones who dont know me,im a blazer veteran. I know most of blazers,especially cpi and tbi injection. But this has me stumped.

Started of as hesitation. Said,k blazers got 170k on it. time to do the spider. at the same time the pump was weak. changed both reman spider(2nd one in a few months),and a delphi pump. Ran decent for a few weeks. Started a bucking like someone slapping the brakes every 2 secs. Did the coil,distributor,ecm coolant sensor,knock sensors,tps,and iac.

Not much change. lower intake was leaking vacuum after doing a ether test. Changed em. Bucking stopped, did plugs too (ac delco) then now random misfire. Put,put put....put...misfire at idle and light acceleration.plugs gapped yes. wires new.

woke up this morning. she started up,still with the darn random misfire. hit reverse then drive. She died. no start afterwards. I checked coil plug wire with a old plug,got spark. replaced cap,no change. Removed the pcv valve line,and poured some gas into the intake. she fired right up,and ran as long as i gave it 3k rpm or more. stilled skipped but it ran as long as i left off the rpm.. Fuel pressure. 58-60 key on,holds decent. My gauge seal leaks a lil. but it doesnt plunge to its death.

Im stressed bad. im bumming rides and barely getting by. If anyone Professional has any advice if you know these systems, or has a cuircut for that spider....it'd help alot.

 

I'm thinking crank sensor

 

In all of the work that you did in and around the intake manifold & injection system, did you ever replace the electrical connector to the spider? I have lost track of the number of people that have replaced just about everything relating to the ignition & fuel system to have the problem be a sub-$20 electrical connector.

 

^I am wondering if this isn't my issue as well?!?! I am battling a similar issue except I have a no start issue all the time. I'm going to look into this myself!

 

The connector on the '95 and older CPI engines is a simple two pin connector that is known to grow weak over time especially if removed a few times.

The 96+ SCFI/MFI engine uses a 12 pin connector that is external to the intake and isn't subjected to the same punishment, nor is it really known for failure due to operating conditions. So your '96 shouldn't have this concern.

 

Bummer