Haynsling

I pulled out of a parking lot last week and rolled into the throttle pretty good (maybe 3/4 full) and the truck started to go as usual. Then she just went to idle speed with my foot still in the pedal. coasted for a short distance and tried letting off and then getting back into the pedal but she wouldnt rev up and died soon there after. I got it started again and barley made it into the nearest pull off (bout 100 yards).truck would start and when i pressed pedal revved a little but seemed like something was limiting rpm.cycled the key a couple times and the obd flashed P0837 and P0148. Ive been messn with cars all my life so I feel like its a fuel delivery issue. Towed it home and now im messing with it. I subscribe to all data diy and am using the fsm to do the appropriate checks. The IP and LP and ALL injectors have been changed about 10- 15000 miles ago(another story) so I'm hoping the IP is still good. Did LP flow test and got over 500ml in 10 seconds. pulled the high pressure line between the IP and the rail and nada!

OK heres the question part... could the FCA cause this? I'm pretty sure its not the PRV/PLV (yet) because it needs fuel to fail or not.

Thanks for your time guys

hot_runner58

I had those codes earlier this year on one track, and last year on my other. I searched on here and found it could be the FCA. I have read on many threads that if you pull the FCA and you can hear it rattle, that it is bad. On the 2 I have had go bad, they did rattle when shook. I have also read that, that isn't a fool proof way to tell. It's just 3 little bolts to change it, so I would give it a try.
My 04.5 had this problem earlier this year, the fca fixed it for a while, and now it dies at random intervals. So, I'm still tracing wires making sure I don't have a hidden short some where.

Haynsling

I got an FCA from a friend that upgraded his IP. Shook it and it didnt rattle. For clarification is eattle god or no good? put it on and the truck started. Before changing the FCA the truck wouldnt even start. now when i step on the pedal she revs up to around 1200rpm and then stutters real bad. like a dropped cylinder on a gas engine. if i let of the pedal it goes back to idle and purrs just fine while in the 7-900 rpm range. im guessing rail pressure isnt where it should be but without a dagnistic scanner what can i do? I was tthinkin of getn an edge monitor so i can see some parameters but not sure if the actual rail pressure is displayed or the demanded (by the pcm). I have the part from the back of a perfectly good IP with the mechanical gears, should i try changing that?

Haynsling

ok I know no one is paying attention but i went out and bought a solus so i could run some better diagnostics. so i found out that the demanded (by the pcm) pressure is not being met. i get 5400ish (demand and actual) at idle but when i press the pedal demand goes up (up to around 11000) and actual goes down (to about 2000). so im loosing pressure somewhere. dont think its the injectors because i did the balance test and every injector passed. so my question is can the pressure relief valve on the top of the fuel rail cause this? i read somewhere that there is a relief valve inside of the IP, is this true. I know there is a check valve in the top of the IP, can this get stuck open allowing too much fuel to return to the tank?

sorry so,long winded jes tryin to be thorough

pw58

get it running yet?

Z-MAN

I have the same issue. Did you get it fixed?

Haynsling

not sure if I mentioned above but during my diagnostics I removed the high pressure line from the rail, loosened the fitting at the IP, turned the line so the bend faces towards the wheel well, connected a 5/8 rubber tube to the open end, and tightened the fitting on the IP. I then cranked the engine over and found that nothing came out. I took the mechanical pump off of the back of the IP and inspected the shaft that drives the gears. Since that was intact I put it back together. I then removed the fitting the the high pressure line connects to on the IP and swapped it out with a donor that a friend gave me( be careful when removing as there is a spring and small steel ball that is part of the pressure relief system in the pump.) put some grease on the spring and stick the bal to it to aid in installation. Ive been told that if yoou do this wrong you can "blow" the IP.I then put everything back together, fired it up and she ran like a champ.

I have no idea which of those things i did fixed her but who cars as its running just fine now. I noticed that on the fitting that i removed ther was some corrosion, its my guess that the spring was not moving freely and was causing the ball to remain open alowwing fuel to return to ???.

Hope this helps

Z-MAN

I really appreciate your info. Right now I'm split between taking the injectors out or replacing the injection pump. I did test the high pressure line and there is not much fuel coming out when I cranked the engine. I did replaced the FCA and I got it running but at low RPM, rough idling, which makes me think that even if the injection pump is running now I will probably have to replace it soon.

Haynsling

the hard line that runs from the IP to the fuel rail is connected to a removeable fitting on the pump. inside is a spring and little ball bearing( essentially a check valve) search how to remove and replace this. when i took mine apart i noticed some corossion that was possibly resrticting the free movement of the spring. dont know how critical this is but im swearing that when i cleaned it thats what fixed my problem. i immediatelty got loads of fuel coming out of the high pressure line

Z-MAN

Iwill do so this weekend and come back here for an update. Thanks