dakota440

I bought a 1988 d100 4x4 SC SB with a 318 tbi no A/C automatic. Anyway I knew it needed a fuel pump so I installed a new one, and fuel filter. Now I can start it and it runs for about 45 seconds then it stalls. It will start right back up but stall again. I checked the fuel pressure which is around 15 to 20 psi consistently. It never loses spark. There is fuel spraying from the injectors at all times. If I spray carb cleaner in the TB it will run longer, but its rough. I also swapped computers with a new one, but still no luck. I could not get a reading off either computer, everything comes up at 0 except the temp reading which reads -178. I disconnected the temp wire, but no luck there. I am running out of ideas and would appreciate some suggestions. Thanks.

Silverick

Maybe the catalytic converter is shot and full of........? If it unbolts, unbolt it, remove it, start the truck and see what happens.

78D200

What are you using for a reader? Being an 88 it would need to be able to communicate with OBD I.

You could have a plugged cat like silverick said. Also check to make sure that you have good, level commpression across all eight cylinders. Did the truck run like this before?

dakota440

has a newer cat on it, i am sure it is not plugged, it has good compression on all cylinders (within 3 or 4 psi of each other). I was using a snap-on scanner that plugs in by the drivers side inner fender. the truck run great before the fuel pump went out, though it did sit for 6 months before I got it. Not a spot of rust on it either, its a shame I cant drive it.

78D200

Is the Snap-On scanner designed to read, or have the right card in it to read, ODB I? If it does, I can't imagine why everything is reading 0 even on two PCMs.

dakota440

It had the correct card and plug. So far all the wiring looks good as well.

78D200

Check to see if you have voltage at the pump the entire time its running and when it stalls. The injectors may still be squirting fuel but only due to the pressure build-up in the line.

I just find it hard that the truck ran fine before the pump went and now that you replaced the pump it only want to run for 45 seconds.

ryuku tatsu

Did you check your pcv valve? should be in the valve cover. My 97 dodge ram, would run and die, replaced the pcv valve and it was good to go, cost all of three dollars. Good luck.

b89raming

I'm having the same problem.. I replaced the FPR, ICS, and the FI. still died out after running about 45 seconds. Also would cut out when pressing the gas pedal.. What was your fix for the issue? Thank you in advance..