Installed a set of ISSPRO guages in the the truck awhile back. Everything was reading good & the needles were steady. Now the needle on my fuel gague is bouncing back & forth from 40-60 PSI never resting at a steady pressure. It just started doing this with the COLD snap we are havig up here. Dropped to -25,-30 and hasnt warmed up to above -15 this whole week. Suppose to get into -40 by the weekend.
Does the gauge going goofy have anything to do with cold weather? Plugged filters?
Only had the gauges a couple months, filters changed 4000kms, & I run Winter diesel kleen. What can I check or need to do?

thanks guys

 

If it does it when fully warmed up , I'd bet on filters.

 

Yes it does it the whole time driving or parked idleing. Even after 30-40 mins driving and everything else is warmed up.
Guess I'll find out how much fun it is to change filters in -30 temps this wknd.

 

Might even be fuel gelling or water in the lijes freezing at those temps. Try to get your hands on a diesel fuel anti-gel formulated additive....Stanadyne, FPPF, DieselKleen, etc...might help

 

Do you have a fuel leak. A leak will make it jump like that also.

 

geling on the inlet side. iceing on the return side, failed pump (pump does have a check valev in it never seen a bad one but hey) or a sticking regulator. thats what I see as possible. assumeming there are no leaks and no fuel aeration. the most common leaks come from the primary housing lid not installed correctly not fully seated as well as the upper filter with the same issue. then they also like to leak at the regulator part of the secondary housing

 

I bet it is an analog gauge with hose to it from the fuel pressure port.
My Autometer fuel gauge started to do the same exact thing after a couple of months. It was perfectly steady at the beginning, than the jumping begin , and finally got unhooked. I live in south FL, where the temp doesn't really go under 40 and it actually happened to me at the beginning of summer, when the temp stays way above 70.
I'm not sure, but if I good remember these gauges has some kind of precise stepper motor in them, and I believe that's what gave up on me, and I wouldn't be surprised, if that's what happened to you.

 

I know this is an old thread but i was just currious if anyone ever found the solution I have a truck that is doing the same thing now except my truck is running really rough when this happens.

 

I never did find out why? I've done the filters many times since. Warm weather, Cold weather. Some days it doesnt move at all... steady at 60psi other days it doesnt stop moving 55-70psi back & forth.

No rough running. No smoking issues. So it I just RUN IT!!

 

Mine is doing the exact same thing. I am going to order a new sender first. Truck runs great.

 

Do any of you have the Blue pressure spring?

My truck went from 60 psi rock steady, to slowly lowering and it started fluctuating down to 45 and then back to about 55 psi

Put the blue spring in and vented the pressure sender. I have the Strictly Diesel adapter/hose for the sender. Pressure has been rock steady at 70-72 psi every since


Hope it's not the gauge. Those are expensive

 

Mine only seems to jump when I sat out loud "I think its gone".

 

Is it an EV2 Isspro gauge? If so, check where the wiring is crimped into the orange connector at the back of the gauge.

The method to attach these is to lay the wires over the orange connector and then push the wires into the orange connector using a special plastic block and a channel locks. The insulation on the wires is displaced by the blades in the orange connector and the blades pick up the current flow through the wires.

I ran into this problem on one of my gauges and improper seating of the wires in the orange connector was the culprit.

 

No mine is a Glowshift.

 

Just saw this post when searching the same issue. My ISSPRO EV2 doesn't swing through nearly so wide of a range (just 60-64) but is constantly moving even at a steady speed and RPM. Do you consider mine to be normal or something might be amiss?