I installed an Aeromotive 340 stealth pump and a fuel pressure gauge this weekend and my fuel pressure is through the roof. Unfortunately because I just installed the gauge also I have no idea what the pressure was before the pump install.

This is an 02 style return setup with the stock delphi regulator. With the engine off when I turn the key and the pump primes I see a little over 80 PSI. I am wondering if the regulator has failed or siezed closed for some reason. I haven't tried to start the car yet so I don't know what the fuel pressure is going to do when the pump runs longer than a prime.

Is it common for fuel pressure to go high when the regulator fails?
Is the pump overloading the regulator? It is advertised as a direct drop in.

 

I would go ahead and start it.. All it will not do is run if there is a issue with the FPR.. Once you start the truck, give it some time, then give it some gas and see that it is rising and falling.. My Fp is about 60 psi at idle.. Yours seems a little high, but I wouldn't be to concerned over high FP..

 

Thanks for the reply.

My concern over the high FP is that when I take it around the block and open it up that 80 PSI is going to boost reference to around 95-100 PSI, and that is a little high for my comfort.

 

Have you used another gauge to check?

 

Negative.

 

Keep a eye on it

 

Do you have a gnome that I can put under my hood to watch the gauge while I drive?

 

Oh I thought you had one inside the vehicle.. well thats the first no no.. Lol

 

Why is that a "no no".

Mechanical gauges are FAR more accurate that electrical gauges that have sending units that fail and fluctuate with voltage.

It's clear to me we aren't going to solve an issue or get any information here.

 

Do you have any logging software or a scanner? If your FP really is that high all your trims will be way negative. If its a gauge error then the trims will be fine, assuming you are properly tuned for it.
Have you ever used that gauge before? Are you 100% sure it is accurate.

Either the gauge is lying or the regulator is broken, and im more inclined to blame a gauge than the reg.