I would say injector issue...(poppets) injectors are aweful. Not the same engine, but we had a 98 van with a 305 (yes i am sure it was a 305) It had a similar coolant leak issue. When we got it all together it was missing bad. After testing everything possible and loosing our *** on the intake job, we used a spare injector assembly just for ***** (again we had already lost out ***) and VROOM. Also if all else fails. I have a 05 4.3 with 51K out of my silverado ill sale you with all accessories and harness .

Best of luck figuring this out.

Dustin

 

A wasted weekend, and $360.00 later it finally runs. I installed a new spider assembly from Napa, and it fired right up The Napa spider is a much better design than the original, it does away with the shitty poppet style injectors. Looks like it might impead airflow a bit but this pos has no power anyway. Thanks everyone for your help, and ideas. I should have doubted GM's shitty engineering over my own work in the first place.

 

From GM the injectors are 180 a piece buyers cost. So you got off good, and that unit looks alot nicer.

Dustin

 

Youve got a newer GM Multec 2 MPFI spider. It replaces the older CSFI poppet spider.
The newer S10's and 4.3's got the newer MPFI Multec 2 spider. They flow the same 19 pph(at 43.5psi) as the CSFI poppets do.
GM was replacing the poppet spiders in Vortec 305/350's in California with a V8 MULTEC 2 spider assembly for free at 1 time.

peace
Hog

 

I took the truck for a drive, and it runs a lot better, between the bad lifter, and failing spider it was getting robbed bad. Runs like a whole new truck now

I know some guys with a dealership in Ca, I will have to check into that, but Im probably screwed because this is a Co, truck and a V6. Would be nice if I could get a new spider from Gm, I could sell it on Ebay and recoop some of my cost.

 

Ill still sell you a new 4.3 haha

Dustin

 

If the 4.3shitter comes out an LS1 will be going back in

 

Damnit...ok then well...know anyone who needs one?

Dustin