2nd Gen Non-Engine/Transmission FP Gauge Accuracy

[ichoplin]

I just bought an 02 3500 two months ago with only 52k on the clock. It's got a new stock LP and IP. I put an Isspro mech FP gauge on it(have used this on other 2nd gens). It's installed per all the recommendations found here.

When I installed it, I had the 1/8" tubing completely bubble free. When I bumped the lp for the first time, pressure went up to 14psi. After the lp quit running, there was a 1/4"-3/8" bubble in the tubing. I figured the gauge was empty, so I refilled the tubing and isolator. After running the lp again, there was still a bubble.

Here's my question after all that, how low will bubbles cause a mechanical gauge read? At idle, I'm usually at 13-14psi, but can suck it down to 6psi at WOT. Do I "add" a couple psi in my head or should I worry. I figured an electronic gauge could be more accurate, but I've had isolators fail on me in the past.

Thanks,

Ian

 

[JLandry]

A bubble that small won't affect the pressure reading.



The only time trapped air becomes a problem is when the bubble is large enough to allow the rubber diaphragm in the isolator to reach its limit of deflection in order to compress the air trapped in the plastic line. It would have to be quite a large amount of trapped air for that to happen.



It sounds like you're fine.



John L.

 

[ichoplin]

Thanks. At least I know I can trust my gauge.

Ian