Hello,
Hoping I can get some help .
I just picked this truck up it’s been sitting for a few years . I first noticed fuel leaking out of the high pressure fuel pump , I replaced the pump .
then on the way home it stalled out on me , I had to sit for 15 minutes let it cool down and it restarted . So it likes to run for a little bit until it warms up then dies , after it cools down it starts back up .
This happens on both tanks .
I rigged a volt meter to the high pressure fuel pump and it seems to loose power right when the truck stalls drops from 13.5 to zero . I’ve also hooked up a fuel pressure dial to the rail and it idles at 35 .
Other things I’ve tried :
tested the fuel pump relay by jumping the pins.
Put in a new distributor with ignition module .
the timing is adjusted properly .
if anybody has any ideas the would be appreciated !

 

The power path comes from the fuel pump relay.
When you first turn the key on the ECA provides the ground for the fuel pump relay to close, but only for 1-2 seconds.. If the ECA receives an RPM signal it will keep the relay energized. If no signal - no fuel. Have you found the diagnostic plug ?

 

Thanks for the reply
I have not found the port .
I guess i should try and read those codes ?

 

The reason I asked about the plug is there is a terminal port on there that if grounded with the key on the fuel pump will run.

The thought here is if something is causing the fuel pump to stop, we can verify one or two things just by making the pump run when we want it to..

When was the last time the fuel filter was changed?

 

Got ya . Sounds like I can run some tests there . I have not changed the fuel filter , I have no idea the last time it was changed , I took it off and blew through it , it was flowing free. But that’s probably the simplest thing to change, I’m sure it could use it . That’s not explaining the power loss at the high pressure fuel pump . Or could that cause the volts to go down to zero ?

 

Sorry I didn't answer that question earlier. BUT if the engine wasn't running providing an RPM signal the fuel pump relay opens and results in no power to pumps.

If we can make the pumps run , we can answer if the problem is fuel or ign.

If the pimps run and it still won't start, should not be fuel, but ign system problem.


Something you might want to check and that is, the multiple pin plug on the passenger side under the battery. That plug goes to the computer and many times corrosion gets in there. If you remove the battery the plug is easier to access.need a 10mm socket to loosen the screw that holds the plug to the ECA.

Something else I didn't ask, when it quits running does it stop just like you shut the key off or does it idle down and then quit like running out of gas?

 

It idles down like it’s running out of gas .
I would like to chat with you more about these possible issues , just pulled up to work, I’ll have to get back to you this evening.
thanks again

 

Does the volt meter you hooked up to hi press pump show any voltage when cranking engine to start after stall ?

Did you check if spark was available after engine quits and won't restart ?

 

I’m starting to think this a fuel delivery issue not an electrical issue, after the truck dies and it doesn’t want to start , if I hit it with starting fluid it fires back up .

 

I agree with you. Keep in mind when you are cranking it over that RPM signal is being generated..

The result MAY be fuel problem, but that can be the result of an electrical problem in the fuel supply system.

Can you try to get a voltage reading at the hi press pump when cranking the engine over and it won't start?