fuel pump only pushing 15-18 PSI???? Please help...

[sfran]

Please help me sort this out. I need my truck this weekend!

So my truck has been acting funny lately and finally wouldn't start the other night. I crawled under and banged on the tank, and presto, the pump came on and it started up while still running not that great. So obviously I assume fuel pump. This is my 4th fuel pump I've done in the 10 years I've owned the truck, now after replacing it this time, the damn thing won't start. I have never had an issue after replacing one before but this one is driving me nuts.

I have checked everything I can think of. I have spark, 11.2 volts (with a weakish battery from cranking, now charging) at the connector on the pump in the tank, I have a good ground, I have tried 2 new pumps, and a new sending unit to compare voltage and pump operation, but can't drop the sending unit in the tank, because then I will have to buy it. I know the pump is kicking on, but it is very quiet. I put a fuel pressure sensor on the fuel rail and I can only get it up to 15-18 psi.

What am I missing, or where should I turn next? My Napa guy said it might be the ignition module. I think this is the one with the heat sink?

I don't want to just throw parts at it so any help would be appreciated.

Thanks

****Update*** just thought to put starter fluid in throttle body, well actually carb cleaner cause its all I have. And voila, it started. So I am assuming I am the unlucky bastard that gets two bad pumps on the same day? Has to be fuel right?