1991 YJ Fuel pump electrical issue

[inhouston2]

[FONT=&quot]1991 YJ 4.0 Automatic. Fuel pump was not working and, by the way, I think it was actually dead. [/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]Before I get there, though, the orange striped wire to the pump is, I understand, supposed to provide about 2 seconds of juice to prime the pump. I could only get it to provide an instant of power, a literal flash with a test light, then nothing. If you move on to cranking, it is powered up during that phase. A rebuilt ecu and changing relays around were no help. Any thoughts? [/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]I would imagine priming is important so it will fire right up. I sure want it is all right before the tank goes back. [/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]Many thanks!
John[/FONT]

 

[JPNinPA]

If the line pressure is at or above 35 psi it will kick off in 1-2 seconds.

If it primes longer and pressure does mot reach 35 psi there is a leak. Maybe a injector stuck or the check valve is bad. If its a new pump it likely has the check valve in the assembly and likely good.

Never look down on anyone unless you are helping them up - Jesse Jackson

 

[inhouston2]

If the line pressure is at or above 35 psi it will kick off in 1-2 seconds.

If it primes longer and pressure does mot reach 35 psi there is a leak. Maybe a injector stuck or the check valve is bad. If its a new pump it likely has the check valve in the assembly and likely good.

Never look down on anyone unless you are helping them up - Jesse Jackson

Makes sense but no line pressure at all since the pump is disconnected and out. It is not kicking off, it is not priming at all. Thanks, John