Started new motor up for first time, FP problem

[Wolfj359]

Well the moment I've been waiting for since January finally came tonight when we started the new motor up. Everything went good with the exception of the car not maintaining fuel pressure. Pressure would hold constant for a few seconds and then immediately fall off causing the car to die. After this happened briefly for 2 times, I decided to hook my jumper wire up to the fuel pump to check if it was working which it was. I started the car back up and plugged in the jumper wire to manually run the pump while I let the motor break in for about 15 minutes. Everything ran beautiful and boy did it sound sweet . Obviously it is not a problem with the fuel pump. I'm thinking its a problem with the fuel pump relay or possibly having something to do with me not having the stock oil pressure safety switch hooked up anymore. I know that on stock applications if the ECM didnt read any oil pressure from the stock safety switch above the oil filter that it would cut off the fuel to kill the motor but I thought that went away with aftermarket chips. I could be wrong. The motor in question is in my signature. Any ideas before I tackle this problem in the morning? Thanks in advance, see you guys in BG.

 

[Steve Hill]

I think you're on the right track. Jumpering battery directly to your fuel pump more-or-less narrows it to something that circuit.
Take the fp relay apart and clean out all the preservative gunk GM put in there. Use electrical contact cleaner (Radio Shack, Graingers, any auto parts store) spray on the contacts.

 

[Steve Wood]

Justin, the oem set up did not allow the oil pressure switch to kill the engine....it was a back up to to the relay. If the relay went out and the oil pressure was above 4#, the engine would continue to run. This would allow you to start the car even with a bad relay.

Sounds like your relay is failing as it warms up. Get a new one.

Glad it cranked okay!

 

[SSprayn]

it is probably just scared of THE BBBB