AstroVannin

Ok, so here it go's.

The truck had low fuel pressure causing severe drivability issues, ie: no power at all. So, in my infinite wisdome I decide that instead of dropping the tank to replace the pump with the propper one I will add an inline pump.

So.... al gos well the pump is installed and connected to two unused wires I find under the dash. The truck starts and runs great. lots of power, all good. So, it seems like the second (inlin) pump is starving for fuel from time to time and causing a whining noise, especially at idle where its on and off with the whining. The problem keps getting worse so I decide that the OE pump has had it and i will use only the inline pump.

Today I drop the tank (i should have just donr this in the first place instead of being lazy) and replace the original pump motor with a custom pickup, basically just a piece of 3/8 line with the original screen on the end. I rewire the inline pump to a new source (the power from the fuel pump relay under the dash).

Then the truck starts right up. I let it run for a bit to get all the air out of the lines and stuff. Its still good, revs nice, idles smooth all that. Then it starts to rev down a bit, then a bit more then it just stalls. I restart it and it idles up for a second then down down stall.

It seems like its running ok when its on "cold start mode" or somthing, but as soon as it warms up that little bit, it stalls. I was going to get a new EFI relay tomorow in the hope that there was somthing wrong with it but I really dont know. I was also thinkin of hooking the inline pump up to the wires for the OE pump, but i cant see that making a difference.

So, I dont really know what to sheck or what to look for next, weird.

I would appreciate any help.

Thanks

wkndrcr

Have you done a pressure check??? Do you know how much fuel pressure is needed VS. how much your "inline" fuel pump is suppling???
If I knew Id tell ya what it needs but I dont, however its the 1st thing I'd be looking at!

PirateFins

per this page of theFSM you should have 265-304 kpa or 38-44 psi of fuel pressure at the cold start injector pipe, when testing fuel pressure. Sounds to me the either your pump is not enough or the regulator is bad. Look at the link for the testing procedures.