GMC Truck Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
I recently helped my dad with a 454 rebuild in a 1988 chevy 1 ton dually. I have everything back in the truck and I can not get the fuel pump or throttle body injectors to fire. Any help would be appreciated.
 

·
Registered
Joined
·
4,874 Posts
Re: Camaro Jack

have you checked the pressure in the fuel line?

also, you generally put a description of your topic in the title, not your name. its more helpful.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
Re: Camaro Jack

Sorry,
I'm new to the forums...I have no fuel at the throttle body unless I run a hot wire directly to the pump.Then it runs fine with plenty of fuel, but it will not try to run by itself.
 

·
Registered
Joined
·
4,874 Posts
Re: Camaro Jack

sounds like something with your fuel pump wiring then. does it make a sound when you prime the truck?
 

·
496BB
Joined
·
1,749 Posts
I'd check the relay and fuze on the firewall


Sent from my Big Block iPhone using Tapatalk
 

·
This place sucks dicks
Joined
·
4,938 Posts
LS mod :imo
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #10 ·
OK, I have changed the fuel pump relay, the oil pressure sensor that goes to the ECM, I've checked ground wires ( All that I can find ) and still can't get the throttle body to spray fuel.. I can feel the fuel pump try to run when the key is turned on , but it only makes a click sound. Everyone I talk to says it is a ground of some type. This thing was running fine before the engine was removed for rebuild, it was just pouring oil from the rear seal.. Is there a way to check that the oil pressure sensor is sending the signal to the ECM? or any other check I can perform???
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #11 ·
Follow up:::

It turned out to be a grounding issue..I have no idea where the actual problem was, so I took a schematic and tied in a new ground at the ECM..Problem solved. Thanks for all the advice.
 

·
Registered
Joined
·
729 Posts
i was going to say check for grounding wire on the frame rail,
when i repainted the frame on mine i missed reconnecting a black ground wire on driver's side frame rail in middle of truck, that prevented the fuel pump from working.

when pulling a motor, it's easy and common to undo a ground strap and completely forget about it during the reinstall.

ideally you want 3 grounds to the frame from the motor, one from each head and one from the starter/block mounting point. the importance of having each head grounded is especially important for aluminum heads, where there might not be a good ground patth for spark plug current to make it to the block which has the ground strap making it's way to the frame and back to battery neg. there can be poor conductance between the head and block due to composite head gaskets, rtv sealant on head bolt/stud threads, and so on, and that'll cause damage. last thing would be to make sure alternator is grounded well in some manner to block either through mounting frame or with a ground strap from stud on alternator housing to truck frame. battery negative goes to either frame or engine block at starter.
 
1 - 12 of 12 Posts
Top