1991 22re 4x4

Truck starts and runs for a sec then dies. I used the diagnostics jumper to test fuel pressure. With a fuel pressure gauge hooked up at the fuel line where the cold start injector is,key in the on position,insert jumper wire I am getting 58 psi,take out the jumper pressure falls to 40 immediately.I think the reason I get good fuel pressure at the diagnostic test is everything is by passed and applying 12v straight to the pump.

If I start the truck the pressure goes to 30 then rapidly falls to zero and truck dies.

Bad fuel pump?

I don't want to just throw parts at it.....I want to figure out what the problem is. Seems like a lot of knowledge here hope some one can help.Thanks

No one???????????

I have searched this forum and I have came across several threads with the same problem without any solutions. The only one possible that was close was a guy had an electrical problem in the wiring harness to the injectors.

Truck starts then immediately dies.

Most people would change the fuel filter first, since that's considered preventive maintenance anyway. It's a a PITA, but something you probably ought to do if it's been more than 50-60k since you did it last.

However, my suspicion would be the fuel pump. Maybe a local parts store would be able to test it for you. Have you called around and asked about that? Plus, I don't think fuel pumps are very expensive either, maybe 50 bucks. So even if that ends up not being the problem you've done some PM.

Who knows, you might take the pump out and discover it's obviously clogged and/or not working.

fuel pump OR the fuel strainer sock that is before the pump in the tank. at least the older toyota tanks have a drain on them. good luck

Sounds like your COR relay is shutting off. Bad AFM or relay.....

Jump +B and FP in the diagnostic block and see if you get pressure.

Yep 58 psi

Took the kick panel off the computer and had a couple wires that were melted. Repaired them and now she runs.

Glad she's back up and running did you have any other problems that the melted wires were causing that are now fixed?

Also it might be a good idea to update the original post with the solution and/or the thread title so maybe it'll help someone in the future.

Could be one of those, "I FIXED IT!" deals where 5 minutes later the problem comes back again.

How do you update the original post?

It has run all day today so hopefully it is fixed. The bad thing is this is my brothers truck....I have about 20 hours in it. Oh well guess that's what brothers are for.