Dropping fuel pressure

[dnovot1]

I am thinking i may have a fuel pump going bad, but would like opinoins:

When car is cold, turn the key fuel pressure goes to it's setting, AFP set to 43 PSI with the vacuum line off, and can adjust pressure accordingly. After several minutes, 10-15 minutes, fuel pressure will drop to between 25-20 psi, no difference if vacuum line is off or on. Adjusting the regulator does not affect fuel pressure either, after this drop has occured. After the car has been turned off, fuel pressure maintains for a while at 25-20 psi. If car is restarted fuel pressure stays at 25-20 psi.

Fuel system components:
Accufab AFP
Walbro 340???, not sure of the number, i purchased it about 1.5 years ago from full throttle.
Changed fuel filter after this issue arose.
60lbs. injectors.
Hot-wire kit connected to alternator.
Stock fuel lines, visually checked but no kinks or anything odd noticed.
No visible leaks

Just curious if any one has had this problem before, i don't just want to throw money, i dont have, at it.

 

[1quick6]

Sure sounds like the fuel pump to me. Your Walbro could be among the batch that had problems. Have you measured the voltage you are getting as close to the pump as possible?

 

[dnovot1]

No, i have not checked any voltages, but i can when i get home

 

[mikestertwo]

I'm surprised the car will even run with that low of a fuel pressure What are you using to measure the fuel pressure?

 

[dnovot1]

I dont remember where i got possibly caspers. The fuel pressure gauge mounted to the fuel rail, with approx. 18" extension to put guage under the wiper while driving.

 

[Scott89TTA]

That's pretty much exactly what mine did when it failed...I was driving and then suddenly it stalled out at a traffic light. After sitting about 5 minutes it started back up...drove down the road about 100 yards and it started cutting off again. It started back up again after a few minutes and that is when I noticed the fuel pressure was about 25-30...it would run for a few minutes and then the fuel pressure would start falling all the way down to 15 or less and it would cut off again. Managed to limp it to our destination (Cecil Dragway) a few miles at a time where we replaced it in the parking lot with a OEM pump and then drove it home. It was a bad Walbro...only ~400 miles on it...turned out to be one of the bad batches that came out about 1-2 years ago. Also purchased it from Full Throttle...sent it back to them and it was replace under a recall. New Walbro back in car and runs great.

 

[buickbert]

mine pump that i got from fullthrottle around the same is currently doing the exacy same thing, im calling them up today to get another one.

buickbert

 

[dnovot1]

buickbert,
Let me know what they say, if they are still replacing them. This fuel pump has less than 200 mile on it, the car is not driven to much.

 

[buickbert]

when i messaged mike directly he said that the period to replace them was over but to give him a call and he would work with me.

forgot to call again yesterday, imma call today and see if they are open. if not then ill call monday

buickbert