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4.3 won't run


Biker920
12-10-2008, 12:51 AM
Evening Folks, a little info on my prob. 94 s15 jimmy,4.3L W code 4x4 4spd auto cpi-repl due to leak fuel pump-repl took hike. fuel filter-repl map sensor-repl. Fuel press 55psi KO relay on,sometimes starts, no power idles ok will turn top rpm when run up slowly. bogs& stumbles when accelerated quickly. No SES or Codes. New cap rotor wires new cat pvc & plugs in oct.08 Ran fair for 120K miles until original fuel pump quit. Any assist gets attaboy award. Thanks ps get me outta this (wife's truck)

MT-2500
12-10-2008, 08:28 AM
Evening Folks, a little info on my prob. 94 s15 jimmy,4.3L W code 4x4 4spd auto cpi-repl due to leak fuel pump-repl took hike. fuel filter-repl map sensor-repl. Fuel press 55psi KO relay on,sometimes starts, no power idles ok will turn top rpm when run up slowly. bogs& stumbles when accelerated quickly. No SES or Codes. New cap rotor wires new cat pvc & plugs in oct.08 Ran fair for 120K miles until original fuel pump quit. Any assist gets attaboy award. Thanks ps get me outta this (wife's truck)

Airtex fuel pump?
If the problem started with fuel pump replacement.

Check that fuel pressure real good/Specs are 55/61
You should see 60 with load on engine running down the raod and 60 on cold cranking.
If not work on that fuel pressure.

If so go over secandary ign system.
What is engine vacuum reding at idle and at 2K rpm?

Biker920
01-03-2009, 06:02 PM
Airtex fuel pump?
If the problem started with fuel pump replacement.

Check that fuel pressure real good/Specs are 55/61
You should see 60 with load on engine running down the raod and 60 on cold cranking.
If not work on that fuel pressure.

If so go over secandary ign system.
What is engine vacuum reding at idle and at 2K rpm? note to MT-2500 Replacement fuel pump blew ecmb fuse & quit took sender assy back to Carquest Auto parts found original purchase was wrong part no. was for tbi. unit not cpi. exchange was made with so sorry for wrong part lookup truck now running better than when bought used 1 year ago thanks 4 feed back.ps.word from friend who runs own repair shop there is GM TSB on hard start involves conversion kit from cpi to sfi no ecm change needed approx cost 4 part $250

MT-2500
01-03-2009, 06:20 PM
note to MT-2500 Replacement fuel pump blew ecmb fuse & quit took sender assy back to Carquest Auto parts found original purchase was wrong part no. was for tbi. unit not cpi. exchange was made with so sorry for wrong part lookup truck now running better than when bought used 1 year ago thanks 4 feed back.ps.word from friend who runs own repair shop there is GM TSB on hard start involves conversion kit from cpi to sfi no ecm change needed approx cost 4 part $250

Thanks for posting back how it went.
I hope the gave you some discount for giving you the wrong part.
If it is running good and starting good I would not worry about the TSB on change over.
Good Luck

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