OK, heres the story. I just bought a 94 s-10 blazer tahoe 2wd with a 4.3 vortec W code. The guy I got it from said it only needs a fuel pump and it would run great (yea right, nothings ever that simple). Got it home and changed the pump and now thats working. Still wont run. So I check the filter and got sprayed in the eyes with high pressure gas (not exactly fun crawling to the house with your eyes on fire!!!!!!). Next I check the schrader valve and got gas there. So gas it getting up to the engine. No fire. Replaced the ngk spark plugs (which were nasty fouled) with ac delco's. It tries to fire but without much luck. The wires appeared to be off so I go online and look up the firing order & wire position. Redo the wires and now its worse than before. So at this point I'm stumped and my dad is ready to ventilate the truck with his 41 mag. HELP!!!!
Oh, I should mention that I talked with the previous owners (2 owners ago) and they told me that they had the truck parked for ~5 years and previously replaced the "central injection unit". What kind of injector set-up does this truck have? Central injection, MPFI, SPFI, throttle body????? Also the vac. system is screwed up but that shouldnt keep the truck from starting should it?
I've owner numerous blazers/ jimmy's before but this is my first vortec and I'm at a loss. Please help!!!!

 

Test the fuel pressure. The truck needs at least 55psi to properly start and it should not drop much at all after the pump shuts off.

Your engine is the CPI engine.

 

Great, Thanks! Played around with it some more today and replaced the plugs, cap and rotor. Still wouldnt start. Took a break and came back with fresh eyes and found that I inserted the rotor 180* out (which explained the back firing through the intake). Fixed that and it actually fired up!! Still runs rough as shizz but I suspect the vac. hoses are to blame. Does anyone have a vac. diagram for this truck?

AuSSenseiter

 

This is the best I could find:

 

Thanks, swartlkk. Thats a start for me.