So I just bought a 97 F-250 and it has pillar gauges, one of them being fuel pressure. It's running maxed out at 100 PSI. Obviously the first step would be to double check that pressure with a tire gauge, but assuming the gauge is reading correct how do I decrease fuel pressure?

 

Do you have electric fuel? What brand of fuel pressure gauge is it? I had a Isspro and mine topped out at 100 so I called them up. It had a bad sender that they had been having problems with and sent me a new one for free.

 

It has the factory fuel pump and system. They are glowshift gauges, it tops out at 100. Sounds like I should check it manually first. Even at full throttle with a TS Chip on high it doesn't flicker. Can't say I looked at it with the truck off to see if it still read 100.

 

^^^^^ And where / how is the sensor / sender plumbed in?

 

It you have the factory style pump the gauge should be pulsating all over the place

 

It's your pressure sensor. Mine is the same way. That pressure sensor is my only complaint with GS gages. I have gone through 4 or 5 of them; none of them lasting more than a couple of months. If you look at their site they have recently changed the fuel pressure gage and sensor. I hope the new setup works better, but I don't think the new sensor will work with the old gage (3 wire vs 2).

Old sensor:

New sensor:

 

My old truck had an isspro fuel pressure gauge and it crapped out too. Weird that they go out so often. I'd rather that be the problem that a bad regulator. Now I just have to figure out the other demons with the truck, like why my number 4 fuse keeps blowing.

 

Take the green wire off and ground it; I bet the gage drops to 0 psi.

 

Yep the sensor is just shot. Were you able to get that sensor free or discounted since it was a manufacturing defect? I don't know if these gauges have any sort of warranty with them.

 

I think they have a one year warranty, and I was able to get a couple of them free on warranty.

 

Make sure you insulate those gauges from the "water hammer" effect of the factory piston-driven fuel pumps. The fuel pump's rapid pulsations are very difficult for fuel gauges to handle without the cushion of a needle valve or purpose-designed snubber/dampener for the gauges.

 

^^^^^ May explain the above-mentioned sensor failures.

 

Could be. I'm running a glowshift fuel pressure gauge and sensor, with my electric fuel, and have had no problem.

 

Yeah it sounds like a fatigue failure...