asidreflex

Hey everyone, I just recently picked up another 91 pickup 4x4 22re 240k. The engine ws shot, so I did a full rebuild. Replaced everything (engine wise) Upgraded the fuel injectors, added a header to get a little more power (yeah right). So here is my dilemma, once everything was installed and hooked up I tried firing it up. Cranked and cranked wouldn't start. Jumped the fuel pump relay and it fired up right away. I got a used one from pull-a-part, installed it, fired up no problem. I drove it twice since then, and after 2 days... won't start again. Tried the whole bypassing the pump relay, still nothing. So that leads me to think it's the pump itself. Here is the fun part, of course the frame is rusted pretty bad, bolts for the bed are just spinning or rounded out. Same with the bolts holding the tank up... FML. So, my options are (1) cut a hole in the bed to access the top of the tank.. and I can guarantee the bolts holding the pump in are going to be shot (rusted) as well. (2) Add a fuel cell in my bed, which i really don't want to do. or (3) run an external fuel pump, hook it up inline to just pull threw the existing fuel lines and through the old not working fuel pump. I imagine I would just have to match the fuel pressure, but has anyone else done this? It sounds to me like it would be a lot easier then any other option, but I could be wrong... ideas?

scope103

How does someone completely rebuild an engine, but not even get to the point where they realize there is no "fuel pump relay"?

I'm going to guess you were jumping the COR (Circuit Opening Relay), which, alas, makes little sense. Instead, you should jump FP to B+ on the diagnostic connector http://personal.utulsa.edu/~nathan-b...28fuelpump.pdf and you don't risk breaking any relays.

So to check if your pump is actually bad, jump FP-B+. You'll be able to hear the pump running. If it runs, I'll guess that junkyard COR is worth almost what you paid for it. (Or course, you could have a problem in the VAF circuit instead; that's what a multimeter is for).

If jumpering doesn't run the fuel pump, I'd still check the wiring all the way back to the pump before pulling the pump out of the tank.

As for your options, I have a hard time believing any external pump would be able to pull the fuel through a stopped pump. And if your rig is as rusted as you fear, you've got a good chance that the tank is full of crud anyway. If the bed-bolts are just spinning, you're going to have to fix them sooner or later; that's what an angle grinder is for.

Good luck!

asidreflex

Ok I guess I tried to type it all too fast, but yes I jumped FP and the B+ at the diagnostic connector, that is how I knew the COR was bad, i refereed to it as a fuel pump relay because I couldn't remember the technical name. As mentioned, once I jumped the FP and B+ the truck started, I replaced the Relay and it then started up and ran for a day. Now it won't start, I tried jumping the FP/B+ connector again and nothing. Which leads me to think the pump is bad.
My problem wouldn't be getting the bed off, more of getting the old pump out, and new one in without having to drill and re-tap every hole.Due to the rust on the frame I do not plan on keeping this truck long, I just need it running to get me threw the winter, then I plan to sell it to find one in much better condition. Trying for a quick and simple fix to get me around

scope103

It all points to a bad fuel pump ... unless your EFI fuse or EFI relay went out. Check your B+ terminal for 12v. Heck, check the FP terminal for continuity to ground; if the pump shorted out you would have blown the EFI fuse. If the fuse is still good and there is continuity to ground, the pump may be okay. If you get no continuity it could be either an open in the pump or a broken wire.

asidreflex

So I checked it again, when jumping the connector I could hear a high pitch whine coming from the tank, but only with the relay bypassed, which tells me the COR is bad, and the pump does work... but the truck still wont start :/ I've sprayed starter fluid into the throttle, still nothing. Plugs, cap, wires are new. It just ran a few days ago!!! Grrrr