Recently after starting my truck it had no throttle. I restarted it and it was fine.
Next day same thing, no throttle, but I noticed fuel pressure guage was only about 6 lbs. It normally runs at 17.
Just recently installed new Fass, so I didnt feel fuel delivery was the issue.
After some other checks and head scratching I added antifreeze to the fuel pressure isolator and the pressure on the guage returned to normal.
It had normal throttle and ran great on the road test. only ran it about 20 minutes.
My question is, how could the fuel pressure isolator cause the issue?
Thinking I may have another problem.

 

It shouldn't..... unless the PCM uses it as well?

 

Isolator has no connections, but maybe the guage itself is hooked to te pcm.
I will have to check. Thank you.

 

I never saw a truck factory with a fuel pressure gauge, the isolator I assume your referring to, is for the gauge which would have no effect on the truck itself. Most definitely would expect the issue to return. Most likely you're looking at an APPS issue (TPS). If you've have the truck awhile and haven't replaced it and plan on keeping the truck a alot longer I would replace it. Dead pedal is symptom that plagues most 2nd gen VP44 trucks. I get mine from www.dodgecumminsapps.com make sure you follow is installation instructions closely and you'll have no issues.

 

Yea, I'm sure isolator is a coincidence.
never changed tps. I will do that. Thank you.