OT: Jeep fuel problem

[jim97gst]

OK, I hope the mods let me get away with this, but I'm having a fuel problem with my 88 Jeep Comanche. I posted in a Jeep forum, but you guys seem to be much more helpful.

The Jeep has a pretty similar fuel setup to a DSM. It's multiport fuel injection with a regulator and a return line. The thing died on me a few weeks ago. I measured the fuel pressure and was getting nothing. I replaced the fuel pump and it ran again. But now, under load, I'm not getting the power I should. At low speeds, low load, everything seems to be fine. I measured the fuel pressure, and it's around 30 psi like it's supposed to be. When I disconnect the vacuum line to the regulator, it's supposed to go up to about 40 psi, but it wasn't. I replaced the fuel pressure regulator, and when I first started it up and did the disconnect test, it did look like it went up to 40 psi like it should, but after connecting and disconnecting the vacuum line once more, it went back how it was at 30 psi with or without the vacuum line.

What's going on here? Is it possible I got a bad fuel pump that won't push more than 30 psi no matter what? Any ideas? Thanks.

 

[Gsxtasy96]

Is the fuel pump an in tank or external, cant remember. When you changed the fuel pump did you change the fuel filter and/or the sock? Just trying to get an idea. Yes you can can receive a faulty fuel pump out of the box. I worked in a parts house and have seen damaged ones out of the box. There not shipped in the safest manner.

 

[jim97gst]

It is an in tank fuel pump. You have to pull the tank to get it out. It's a big pain. Yes, the pump came with a new sock and the first thing I replaced when it stopped running was the fuel filter.