veleno

That's a great idea!
I'm really anxious to know the results.

veleno

A little update.

So I tried this bypass and got 35 psi on the gauge. I guess that's telling me that the fpr is fine and there is something else after it that's the problem. I did not have a lot of free time but I'm hoping I can do more trouble shooting this weekend.

I believe there is a rubber hose before the fuel tank on the return line? If there is then I'll remove it and blow air from the fpr side to see if it's clear. If it is, then next is the rubber hose/tank pieces.

I feel like I'm close to finding the problem but man it's taking me a while!

Is there a pump in the tank?

Thanks again for the ideas guys. Keep them coming.

jwade944

There is no pump in the tank. The fuel pressure regulator is located on the fuel supply line to the rail. At the fuel return line connection to the rail, there is a dampener. I don't know if it is possible for this to fail closed, but you should check it too. Similar test to the one you ran on the FPR with a tube from the dampener outlet to a bucket. What year is your car?

veleno

I thought it was the other way around? The supply line connects to the damper while the return line connects to the fpr. Car is an '88. Because I got perfect pressure on the gauge with the jumper hose off of the fpr, I have ruled out the fpr. However, if anyone thinks differently please comment.

944Ross

There is no flow thru the dampener (unless it's failed, then it would be leaking to the outside). It seems clear your return line is the problem, possibly something on the return line inside the tank.

kev951

have you checked the entire fuel return line from front to back for any kinks or wicked bends or out of shape hose? the inner rubber line may have collapsed on part of the return line , so check under the hood, check near the passenger caster block where there is a fuel junction, check above torsion bars on rear passenger side, the remaining fuel line heads up to the top of the tank. And yes, supply line to damper, rail, then regulator to return line

mytrplseven

I borrowed a fuel system test kit from Autozone and they didn't have an adapter so I used a section of 3/8 line and put it on the 12mm threads behind the fuel rail cap. Ran the tests noted on Clarks garage and mine is right on. My point is that Autozone will "loan" you the proper test gear after leaving a sizeable deposit. Cheaper than buying $50 worth of guages, clamps and adapters.