Engine/Transmission (1998.5 - 2002) FP gauge "stuck" seems to have restricted movement

[Hohn]

Any ideas?



My FP gauge is a Mechanical Hewitt from Enterprise. I have it plumbed off the Schrader via grease gun into an isolator into braided line right to the gauge.



Today it seemed to stick. I can't get it below 13 psi now. At shutdown, it stops at 11 psi or so. It used to hang up at 5 if it stopped that high at all. Idle reads a pound higher or so.



I used to be able to pull it down to 7 or so with a WOT run, but now it won't budge.



Could the isolator be stuck? How do I unstick it? How is it that idle reading is up to 17 now?



Any suggestions are appreciated, as this one has me baffled how FP could just suddenly start reading much higher under power.



HOHN

 

[illflem]

Doubt it's the isolator. The gauges I use on water systems and boilers occasionally do the same thing, usually tapping them releases the lock up. Since you probably don't want to tap on your gauge all the time to make sure it's reading correctly you might have to replace it. The inside of a gauge has a couple of fine gears that look like they belong in a watch, just a tiny bit of misalignment and the needle will stick.