Quote:
Originally Posted by rfmaster
In view of post #14 to 16 I would check the following:
1) FP voltage at the tank interface during cranking. This should be solid 11.4 to 12.0 volts
2) Check fuel supply lines for any restrictions, kinks etc. FF was replaced, correct?
3) I have suspicion that you may have a bad in tank hose between fuel pump and tank feed through assembly. The 12 PSI that you see during cranking might be compressed air in the fuel line. Since you have 18 PSI spring you should see 17 to 18 PSI during cranking (I use 18 PSI springs in my TB's as well).
4) fuel pump internal pressure regulator is bad.
You can manual force FP to operate by applying +12 volt to the red pig tail dangling from FP relay socket - no engine cranking is required. Run a fused (10 AMP inline fuse) jumper wire from +BAT to this pig tail. While FP is running perform a deadhead test by pinching return line - find rubber section and pinch it gently with pliers. Fuel pressure should increase well above 25 PSI if you have upgraded to TPI pump. If it does not look for a leaky fuel hose inside gas tank.
//RF
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I will check fuel pump voltage during cranking tomorrow since I will actually have most of the day to work on it.
Yes I replaced the fuel filter. There are no kinks in any of the lines from the switch valve to the throttle body or any visible damage. Hard to tell since they are braided stainless lines from the fuel filter upto the throttle body and the short steel piece from the braided line to the switch valve is straight and clean. I replaced the hoses from the tank to the switch valve with new and they are not kinked. I know it is possible to get a bad fuel pump right out of the box I just hope that's not it. That tank was a pain since it was almost full.
I will also do the pinch test tomorrow. And the hose from the pump to the feed line looks like they put a 55gal barrel on it instead of the wimpy little line I am used to seeing. It is over 1/2" thick on these new pumps. I would hope I didn't somehow cut it putting the new unit in the tank but i guess anything is possible.
Do you know what might have caused the system to suddenly have a slow bleed off of fuel pressure after prime or running just from putting in the new fuel filter? I noticed even after changing the pump and it did it all week until it suddenly died on me. After that, the pressure again bleeds off as soon as the pump stops. I dont know if that actually has to do with anything but just found it odd.