No fuel new pump

[rob cole]

I have an 88 g-10 with the 4.3 v 6 TBI I Have no fuel at the throttle body so I thought fuel pump . I replaced the pump and filter and still no fuel . I can see the throttle body and not a drop is coming out. pressure tested ok nothing is going to return line and strangely the pump runs 15 seconds after the key is turned off, (after trying to crank) I don’t remember hearing it run after key off before. I can pour some gas down the hatch and it runs good for long enough to burn that up not sure what to try next. any suggestions would be most helpful

[MT-2500]

Originally Posted by rob cole

I have an 88 g-10 with the 4.3 v 6 TBI I Have no fuel at the throttle body so I thought fuel pump . I replaced the pump and filter and still no fuel . I can see the throttle body and not a drop is coming out. pressure tested ok nothing is going to return line and strangely the pump runs 15 seconds after the key is turned off, (after trying to crank) I don’t remember hearing it run after key off before. I can pour some gas down the hatch and it runs good for long enough to burn that up not sure what to try next. any suggestions would be most helpful

First make sure fuel pressure is up to specs.
9-13 lbs key on and engine cranking.
If good there check for 12 volt power to positive side of injectors.

If no power there check fuse.

If 12 volt power there and still no start check for injector pulse while cranking.

Post back what you find.

[rob cole]

Thanks I will do the pulse check today. the pump tested at 14 lbs so that looks good and I disconected the line and got soaked with fuel so I know its getting up there good. If the pulse is not getting power what next?

[MT-2500]

Originally Posted by rob cole

Thanks I will do the pulse check today. the pump tested at 14 lbs so that looks good and I disconected the line and got soaked with fuel so I know its getting up there good. If the pulse is not getting power what next?

The pulse is a ground pulse.
But do not go grounding the circuits.
That can blow PCM.

Only check for pulse with a injector tester noide light.

One step at a time.
1- fuel pressure while CRANKING.
2- 12 VOLTS TO INJECTOR CRANKING.
3- INJECTOR PULSE WHILE CRANKING

IF ALL 3 IT SHOULD START.

Are you getting 12 volts to neg side of injector?
If so then check pulse with injector pulse noid light.

Let us know what you find.

[rob cole]

Thanks for the info I will post my findings tomorrow

[rob cole]

Got 12 volts no pulse now what this thing needs to go. THANKS !!!

[rhandwor]

Originally Posted by rob cole

Got 12 volts no pulse now what this thing needs to go. THANKS !!!

A junkyard distributor should get you going.

[rob cole]

Why would a distributor need replaced checked the icm inside it was ok. I am slow to post I may also be slow understanding this thing fires right away when primed till fuel gets burned. Thanks for your reply/s

[rhandwor]

Originally Posted by rob cole

Why would a distributor need replaced checked the icm inside it was ok. I am slow to post I may also be slow understanding this thing fires right away when primed till fuel gets burned. Thanks for your reply/s

http://www.ehow.com/how_7419690_1988-gmc-pickup-coil-installation.html I don't understand how it fires with no pulse which you stated earlier.

[dorfboy]

If your pump is working nd you are getting fuel up to the injectors, I would focus on this portion of the problem. I would check your fuse for the the injectors and see if you get power and ground.

[rob cole]

All fueses good power at the injectors no ground pulse as I said before looks like its probably the ecm its letting it fire but thats all only 100.00 bucks but what if I buy that and it doesnt fix the pulse ( broken wire someplace? ) Then I will call tow truck to haul it off ( so frustrated) I have been working on this sence there was 15 inches of snow on the ground tomorrow its 80