I am having fuel delivery issues on my 89 trooper (2.6L).

When the ignition switch is on I am not getting power to the fuel pump, it basically kills the #11,12,13 block of the fuse box (therefore the blower fan for A/C doesn't work, etc.). When I pull the engine relay, then I can get power to these items, so I know that all the circuits are working okay and there isn't a loose ground somewhere, but it makes me think there is a malfunctioning switch or sensor somewhere.

The diagnostic codes do not reveal any problems, the fuel pump is brand new and I hardwired it to test (it worked fine).

I have heard of an oil level sensor in these vehicles and if it detects low oil level or goes bad it will cut the fuel pump off, but i don't know where this might be and there is nothing about it in my shop manual.

At this point my brain is totally stuck with this problem, so if anyone has experience with this or a fresh idea that would be great.

 

the fuel pump is controlled by the computer, it will run a few secounds when you turn on the key then stop, then when the engine starts the pump will runn again and continue to run as the demand is there, if the engine staalls it shuts the pump off again.

Jack been here with this one on my 89 as well