L29 Issues after FPR Repalcement

[Biggershaft96]

Hopefully thatll take care of it.

 

[Christian Steffen]

Yeah I hope so too, I'm getting tired of chasing this problem around. I'll be sure to report back my findings.

Thanks for your help.

 

[Biggershaft96]

Might look around online and see if the pump you have has a built in check valve. From what ive read a bad check valve would make the psi drop to zero once the pump kicks off as well.

 

[Christian Steffen]

Might look around online and see if the pump you have has a built in check valve. From what ive read a bad check valve would make the psi drop to zero once the pump kicks off as well.

I'm gonna have to check into that. In the quick search I did that does sound like the same symptoms as I am having. The pump I got is the walbro GSS340, any idea how to figure out if it has a built in check valve?

 

[Biggershaft96]

Best bet would be to call walbro and ask lol.

 

[Christian Steffen]

Yep I think that's what I'm going to have to do. I'll let ya know what I can figure out.

 

[Christian Steffen]

Updated:

So i don't believe the check valve in the pump is an issue. I shut off that T in being used for "cooling" that I had put in. Now the truck starts 100% how it should, but when I hook a gauge up it still sits at about 48.5 psi when idling. It does manage to get up to ~54 psi when I go to WOT. The fuel pressure still leaks down, but since plugging that T it is much slower. It lost ~ 4 psi in the few minutes I sat and watched it. So what do you guys think, FPR again? Perhaps the one I got from summit is just bad. Or possibly one of the connections at the T in the tank is slowly leaking?

I appreciate any thoughts offered here.

 

[Christian Steffen]

I should just rename this thread to: "I'm getting F***ing tired of not having the correct fuel pressure."

 

[Jrgunn5150]

Updated:

So i don't believe the check valve in the pump is an issue. I shut off that T in being used for "cooling" that I had put in. Now the truck starts 100% how it should, but when I hook a gauge up it still sits at about 48.5 psi when idling. It does manage to get up to ~54 psi when I go to WOT. The fuel pressure still leaks down, but since plugging that T it is much slower. It lost ~ 4 psi in the few minutes I sat and watched it. So what do you guys think, FPR again? Perhaps the one I got from summit is just bad. Or possibly one of the connections at the T in the tank is slowly leaking?

I appreciate any thoughts offered here.

I'm lost as to what "Tee" you are talking about, in the pickup you tee'd it?

 

[Christian Steffen]

I'm lost as to what "Tee" you are talking about, in the pickup you tee'd it?

http://www.gmtruckcentral.com/articles/Walbro.html

In this article showing the installation of the walbro 255 (the pump I installed) the author recommended doing this. I blindly followed this without really thinking about the affects it would have on the fuel pressure. I should have probably linked that from the beginning, my bad. I posted a picture on the previous page, that is from the article, to give an idea of what I meant.

Anyway, at this point I do not believe the pump to be the issue, I'm thinking it is probably the fuel pressure regulator since the pressure is still bleeding down and it doesn't run at the pressure it should.