FPR Question

[93TwotoneXLT]

Has anyone ever installed a autozone FPR? The name brand is GP Sorenson. I installed the first one when I did the intake manifold. On the way back from IN I got off of the gas then back on it and got spark knock. Pulled over to get my wife a drink and check things out and heard a metallic whistling sound coming from the FPR. Truck didn't run bad, just had a little less power going up hills. This happened after being on the road for about 7 hours, up to that point truck was running great, only problem being a high idle that I believe to be part of the FPR issue. Got home last night and today on my lunch break exchanged the FPR for another one. Now, this aftermarket piece has two O-rings with it. There is one that is already attached to the nipple of the FPR and another in the box. I didn't try to use the other O-ring on the first one I installed because I didn't see anywhere to put it, and the haynes manual didn't say anything about any O-rings, just how to take it out. So this time I decided to see if it went inside the port of the fuel rail. The O-ring went in ok but when I tried to put the FPR in it just didn't feel "right" and would come out with just a little bit of pressure, whereas the other one took a little muscle to pull it out. So I took the O-ring out of the port and just installed the new FPR and fired it up. BTW, I remembered to lube the O-ring with a little bit of oil. New FPR still has the metallic whistling but not as loud, and the idle is still around 1K. Anyone have any experience with this? Are you supposed to put the other O-ring in the port and just tighten it down to create a more "snug" seal? Or should I just bite the bullet and get a motorcraft FPR? Note: I did change out the vaccum coupling that goes into the FPR. The factory one had lost its bite on the vaccum fitting of the FPR so I replaced it with one from autozone that is the same style, but slightly smaller than the original, so the plastic vaccum line won't go all the way into the fitting, but still feels good and I feel no air coming out of it. I know this is long and I apologize but I thought it would be better to be thourough about what is going on. Thanks in advance for all replies. Oh yeah, no CEL, light is working.

 

[Bwana Bob]

I put the Autozone GP Sorensen in my 92. I have had no problems. I can look up how many miles I have in it. The extra "O" ring is a spare; you only need one.

This is my third FPR in 14 years and 200,000 miles. The first 2 were Motorcraft. When the second one failed, I cut it open and found that part of it had rusted. Actually, I'm hoping that the GP Sorensen will be better than the Motorcraft FPR.

Check for other funny things around the engine. You can but a fuel pressure gauge at Autozone, but my guess is that something else is wrong. Did you reset the computer (disconnect the battery) after changing the FPR?

Sorry I can't be of more help.

Bob

 

[93TwotoneXLT]

Bwana Bob, I reset the computer after replacing the first fpr. After replacing this one I have the same sound just not as loud so I have to assume that it is not related to resetting the computer. The weird thing is that I have no fuel smell, no cel and the truck starts right up. The metallic whistling sound is still there and I am certain that the fpr is the culprit. I noticed that the fuel line connector to the top of the fpr will retract a little exposing the nozzle. Anyone know if I should have pulled that back, put the line on, then tightened it down? I just screwed the connector back on, restored pressure and fired it up. I did replace both of the vaccum couplings connected to the hard plastic line with new couplings that are slightly smaller than the factory couplings. Anyone think that these slightly smaller/tighter couplings could be creating a more violent wind tunnel than the factory couplings, therefore affecting the fuel pressure and causing the whistling and 1K idle? I know that this sounds like a vaccum leak but the noise if coming from directly above the fpr and I have no driveability problems whatsoever. No surging, whooshing leaking vaccum sound, nada. The engine revs quickly when the gas is goosed and the power all there. No black smoke that would tell me that the engine is running rich, no weird smells in the exhaust, etc. Please keep the replies coming, I really appreciate all of the help.

 

[93TwotoneXLT]

Just an update: Still no cel, and the truck is starting to idle better. In drive, the truck idles at about 7-750rpm. In park, warmed up it is idling between 8-900rpm. Unfortunately, the whistling sound from the fpr is still there. I used a stethoscope to listen to everything around that area and it is definately coming from the fpr, everything else seems to be sealed up really well, and the truck runs great. Filled up and fuel economy city/hwy mix was a little over 20mpg. I am beginning to think that the gp sorenson fpr is just not calibrated correctly for my truck, or that the new smaller/tighter vaccum couplings are affecting the vaccum negatively. I am going to go to the ford dealer tomorrow and buy some factory couplings and see if that helps. If after a week this does nothing I am going to take this fpr back to autozone and get a motorcraft fpr. Thanks for all of the views and if anyone has any ideas feel free to share. Thanks.