Fuel pressure drop

[BoostedBeaver]

So I had to drop my tank and have it cleaned on my 90 talon. Reinstalled everything and she runs like a dream, but when I cut her off she losses all of the fuel pressure within 2-3 seconds it is that fast but there are no leaks to be found. Just wondering if you had any ideas on what I could check and once again there are no fuel leaks and the car runs awsome just takes a min to start cause I have to build fuel pressure. Could it be that I have a walbro 255 on stock fpr and the pressure relief valve isnt closing on the pump and that is why I lossing all the pressure??? Any help is appreciated thanks

 

[troppo loungo]

Its not because you have a Walbro pump unless its incorrectly installed or leaking at the connection at the pump to the line and draining back.

 

[BoostedBeaver]

I understand that but I was just wondering if it could be something else.(like some little flaw I didnt know about). Im going to pull the pump tommorow and make sure it is installed correct. I will post back afterwards. Once again no leaks visible just looses all pressure really fast. It must be in the tank cause its not leaking anywhere.

 

[frankenstein406]

is it rewired?

 

[Red97Eclipseboy]

I understand that but I was just wondering if it could be something else.(like some little flaw I didnt know about). Im going to pull the pump tommorow and make sure it is installed correct. I will post back afterwards. Once again no leaks visible just looses all pressure really fast. It must be in the tank cause its not leaking anywhere.

Check all the fittings on the assembly and on the pump. There could be a small leak. I have seen it happen and he had the same symptoms as you.

 

[BoostedBeaver]

Yes the walbro is rewired but that would have nothing to do with the pump loosing all its pressure after it is turned off. The only high pressure fitting that I took off was the fitting from the sending unit. Checked it and it is fine. Must be the pump.

 

[solidviper89]

The oring like troppo loungo said... mine was installed improperly and I kept having issues, I blamed an aeromotive AFPR on all my issues. Well a few weeks ago I finally decided to make things right. I took out the sending unit and sure enough the o ring was installed wrong. So I fixed things up and everything has been great since!

 

[steve]

when I cut her off she losses all of the fuel pressure within 2-3 seconds it is that fast but there are no leaks to be found. Just wondering if you had any ideas on what I could check and once again there are no fuel leaks.

How did you inspect for leaks inside the tank while it was running and submersed?

It's the connection between the pump outlet and the tube that usually leaks. Either the o-ring or the plastic fitting you moved over from the old pump doesn't seal.

 

[frankenstein406]

Yes the walbro is rewired but that would have nothing to do with the pump loosing all its pressure after it is turned off. The only high pressure fitting that I took off was the fitting from the sending unit. Checked it and it is fine. Must be the pump.

:facepalm: don't rewire with stock fpr.

 

[BoostedBeaver]

Ok thanks for all of the replies. I pulled the pump this past weekend and sure enough the oring was installed incorrectly. It was pooking out on one side, replaced it and wa-la fuel pressure stayed like normal. Now I have an aeromotive AFPR and I installed it the a few days latter once again I only took loose a few fittings but once again Im loosing all of my fuel pressure soon after cutting off the car. Could the AFPR be bad or is it another leak that I cant spot. Thanks

 

[steve]

It's hard to say if the AFPR is bad or just they way it works. A lot of people report the same issue but there are enough that don't have the problem and some that say they took it apart and found stuff on the seat that had no leaks after to make me wonder.

 

[#40Fan]

Check that o-ring again. Might have popped out on you.