Haveing a problem with truck. It has a lopy idle when it goes onto high idle, regular idle (750 rpm) it levels out and seems to run good but does have a rattle intermitatly. I just installed a RP gauge and idle pressure is around 5K running down the highway it hovers around 7.5K not sure if these numbers are good or bad but they are what I got. I am installing a plug in the high pressure relief valve now and gonna see if makes a diff. Had fuel at the fitting, when I ran truck with the banjo bolt out didn't notice fuel coming out of the valve but had a full stream coming from the return line all over side of engine on to the garge floor . Any advice or ideas about lopy high idle would help

 

Let me know what you find out, I have the same issue with mine but it only does it when the truck goes into high idle by itself. If I set the idle it won't do it. Took the truck to the dealer and they put in the newest updates, and the truck still does it. Alot of people will try to tell you its the grid heater, ITS NOT. Delear wants me to bring the truck back buy so they can hook up to it whiles its loping, but its to warm now for it to go into high idle.

 

Installed the plug in the banjo bolt. Take your time taping the bolt use lots of cutting oil or lube. The case of the bolt flexes abit with the conical shape of the tap. It would suck it ya break the tap . I then mixed up a small amount of 5 min JB weld and applied to the threads after cleaning and degreaseing the inside of the bolt and the plug. Threaded plug into bolt and snugged it up. Then used my heat gun to heat bolt abit due to it being cool in the garage to help speed the cureing of the epoxy. Then installed the bolt. Total time was about 1/2 hour. Then went for a drive and these are my finds:

before after
idle 4.5-5.5K 5.5-6K These numbers are +/-
intown 40Kph 5-6K 8.5-9K because had to keep at
Highway 6.5-7K 9-10K least one eye on the road
about 75% throttle 10K 17K

Also the under runnning temp "rattle", sounded like a 12v with about 4mins of warm-up time at -25C, is almost completely gone. Yesterday morn when it went to high idle it didnot surge and LP pressure gauge stayed nice and steady no bounce up and down. Motor seems to be quieter , not sure if it is or just thinkin it is, but with out a before after before after switch compare I still think it made a difference So if things stay smooth then I probly will be ordering the solid Pressure relief valve to make it permanent. Will post agian once I get more running cycles and if any changes.