I have a 92 xj with a 4.0. it will start run for about 2 seconds and die. with key on I have g
ood fuel pressure as soon as it starts the pressure drops to 0 and it dies then the pressure goes back to normal. I removed the return fuel line to see if the regulator was Letting it to bleed off and its not. any thoughts?

 

Bypass the fuel pump ballast resistor and see if it stays running. It's in the engine bay screwed to the inside of the fender. Power to the fuel pump goes thru the ign switch for the first 3 secs, the the ecm/pcm switches power to pump thru the resistor. It's supposed to lower the noise from the pump. Was deleleted on later models. Jump/bypass the resistor with a test lead to test it.

 

that was,it. thank you very much. is that something. that I can just eliminate or is it necessary.

 

If I remember correctly you can delete it.

 

You can ditch it. Fuel pump may be a bit louder.