HydraulicGuy

I installed gauges from my old truck into my new used 03' yesterday and the fuel pressure was around 10 psi at idle. No change at WOT under load. I took off this afternoon for a 250 mile trip and about 100 miles into my trip the fuel pressure started climbing slowly. It got up to about 25 psi before I shut it down. I still had 25 psi on the gauge after the truck was shut down for about 10 minutes. I opened the bleeder screw on my isolator and the gauge went back down to 0. I ran down the highway for a few miles and the pressure started coming right back up. I pulled the line off the banjo bolt and capped it so my gauge wasn't tore up and continued my trip. Truck starts and runs fine. Any ideas???

Thanks

HydraulicGuy

Could anything in my injector pump cause this? Return line?????? Sombodys got to have a thought.

Blast Chamber

Where exactly is this reading being taken from, pre-filter or post-filter?

If it is taken pre-filter it sounds like your filter is getting plugged maybe due to dirty fuel? IF it is post-filter then it sounds like some sort of obstruction in the return line. Is your lift pump system still stock?

HydraulicGuy

I'm pulling pressure right off the injection pump with a tapped banjo bolt. So if my filter was plugged the pressure should drop due to reduced flow. I'm not well versed in on the internals of the CP3 as compared to the VP44 on my old truck but I was thinking maybe an obstruction on the return line as well. Hopefully some more ideas will get piped in.

Thanks!!

N.Johnson

Try getting a cheap mechanical guage and and thread it in to the isolator itself. That will help tell if your cab gauge is the culprit. You say you used your old gauges and swapped over. Did you also use the old 1/8" lines for the isolator to cp3 and gauge? I would change the the brass ferrules on the compression fittings and cut the feed lines back alittle.