I put a glow shift 100 psi fuel pressure gauge in a few weeks ago and it has been working fine. Today it started jumping all around the full range of the gauge. I put a manual gauge in the same fitting and fuel pressure is normal. I checked the ground and it is good. The gauge only does this while the engine is running. I even tried turning the key on and shaking the wires around at the sender and it didnt flinch. As soon as it starts it goes nuts again. I unhooked the wires from the sender and checked it with an ohlm meter and the resistance was jumping from 6 to 36 ohlms. I am assuming that the sender is bad but I just wanted to make sure I didnt over look anything.

 

Did you run a ground straight to the battery? Try that first.

With any Autometer, and now Glowshifts, I recommend a power line straight from the batter and a ground to a grounding point the goes straight to the battery.

If people would do this, the gauges work no problem.

 

Bill, you can put in a snubber or a needle valve to stop the pulsations, Or like you said you have a bad sender. I've had mine on my 24v for two years and no problems.

Good luck,

John

 

I have a snubber in it already. It has been working fine for 2 weeks. I will try the ground to the battery.