911 Fuel Pressure ????

[justinlogue5_0]

(E99 7.3) How do I know if my truck is loosing fuel pressure? And what is the bare minimum before the truck dies? Reason is this morning while pulling aload to work (8,000 lbs plus the truck itself) my service engine light would come on under a straign (Serious head wind this morning) and would go back out as soon as the truck leveled off. All gages showed normal the whole time Including my fuel pressure gage. Got in in to go to lunch and took off (no trailer) and it ran fine but my FPG bounced around and stayed at about 42 for a few seconds before going back to about 62 psi. I have a 50 mile drive home and am wondering what my chances are. I hope my gage has just gone bad but????

[justinlogue5_0]

Well if anyone was worried about me I made it home ok. On one hill while the truck was lugging a little the light came on again but my fuel gage never dropped below 60 and never went over 64. When I got close to home ( in case it was to break down) I started playing with it some. I could mash the motor and it ran smooth and pulled hard with no engine light or fuel drop. I don't have my programmer anymore so I can't check the codes. Gonna see if I can get a buddy of mine to check them for me and see whats going on. Anyone got any ideas in the meantime?

[jesilvas]

Maybe low HPOP pressure?
Fuel PSI should be 55 min I'd say. Low boost possibly. Too many things it could be.

[Quickhorse]

My guess is the map sensor was sensing an overboost situation (unless you have a boost fooler) and was defueling the truck along w/setting off the engine light. You will also get a code in there for the modified IDM just so you know and don't get worried.

[justinlogue5_0]

Originally Posted by Quickhorse

My guess is the map sensor was sensing an overboost situation (unless you have a boost fooler) and was defueling the truck along w/setting off the engine light. You will also get a code in there for the modified IDM just so you know and don't get worried.

Hey thanks man I do have a boost fooler on there but I had it all off the other day (couple weeks ago) when I installed my new 17* Terminator HPOP SO some thing might have come loose, broke etc... I forgot all about it till you just mentioned it. I will check that out. Also I will post back when I can get those codes pulled and see what it says was really going on.

[justinlogue5_0]

I had the codes ran this week end by my friend (snap on scanner) and a lot of them I am thinking was on there from a couple weeks ago when I put my new HPOP on and started it up. ICP,IPR, and HPOP related codes. I also have one for the EBPV which I keep unplugged so thats a no brainer. The P1211 is probably from 1 of 2 things. 1 is from where I put the new HPOP on OR the new modded 17* HPOP is over pumping for what my factory (E99) injectors can take/handle. The one that has me a little confused is the P1249 waste gate. I do not have it unplugged and never have had this code before, untill recently AFTER I installed the new HPOP. I do have a boost fooler but according to my boost gage I never see over 20psi. So did I mess some thing up (possible cracked vacume line etc...) or is it another side effect of bigger HPOP and still factory injectors?

[justinlogue5_0]

Oh, and the fuel pressure gage must have just been a short or some thing because it hasn't acted up again.