Fuel pump issue

[dssranger]

I have 86 4x4 with twin tanks. It suddenly went out sputtered and will not start. definately the fuel delivery. I have checked the reset on the ertia, nothing. I think I will put a jumper wire just to make sure. But I do hear at least the tank pump come on then I hear the the fuel relay click and then nothing. Could it be the relay that fails or something on the pump side forcing the relay to click off? Any ideas or just start with the ertia jumper? I was wondering if the high pressure pump failed if the tank pump would shut down?

 

[Earl43P]

When "key to Run, no crank", the fuel pumps "prime" for about 3 seconds.

If you can't hear the frame rail pump, it's the problem. Check for power (remember, it's only there for those 3 secs.) and ground at its connector, if present = bad pump.

 

[Psychopete]

With a no start, you should check to make sure that you have spark or fuel. Spraying starting fluid into the upper intake manifold and seeing if it will start temporarily seems to be a good way to check. If it starts on that, definitely fuel delivery and the ignition is not the problem.

Should be a frame pump that fires up too, but they are run through the same relay and wiring. Best way to check on the fuel system is with a fuel pressure tester. System should run for 1-2 seconds 2 times each and prime to around 35-40 PSI. A fuel pressure tester is a good tool to have in your arsenal if you work on your own vehicles, one of the first thing I check on diagnosing a lot of stuff to make sure that system is working as it should. If you don't know it will have you working in circles if it's not in spec.

Pete

 

[79F1504X400]

When "key to Run, no crank", the fuel pumps "prime" for about 3 seconds.

If you can't hear the frame rail pump, it's the problem. Check for power (remember, it's only there for those 3 secs.) and ground at its connector, if present = bad pump.

Not tryin' to hijack... but when I pull the connector apart on the front pump, the one in the tank starts to run with key off. I was thinking about applying 12v right to the Hi vol. pump. to see if it would run. Also, is the fuel supply line blue and the return line clear?