Rail pressure at idle

[Chevy1925]

So heres one for you guys. With the truck at idle in park after first start up rp is at a command 5000 . If i rev the motor, rp drops to 14000 even though comanded is 5000. Shut the truck off and restart, actual goes right to 5000. Hit the throttle again and it hangs at 14000 again. This explains my lopey idle and loud injectors i was feelin/hearin every so often but didnt think too much about it.

If it were a sticky regulator, wouldnt shutting the truck off and restartin have no affect on where the reg was sticking? Im a bit puzzled

 

[Devon]

I know with my number 8 injector is what sticking wide open here and there. Resembled a bad fpr except the rail pressure wasn't jumping. Just the balance rates. But prior to that I did have a lope in my Fpr. But only a 2kpsi difference from desired to actual going up and down up and down. I would think its your Fpr playing games with you. They seem to do funny shit when there on the way out.


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[Chevy1925]

Problem is, i have two lol. Not sure where or how to start diag between them as they both will go to 26k and hold.

 

[SSchmi5519]

Try it on the stock tune for starters...that eliminates one thing. Full flash it to make sure nothing is corrupted in the OS as well.

 

[hondarider552]

FULL FLASH :woott:

 

[SSchmi5519]

FULL FLASH :woott:

Brian shits his pants when he hears someone say "full flash" out loud. I have to hand signal it to him like a baseball coach :spit:

 

[Chevy1925]

Brian shits his pants when he hears someone say "full flash" out loud. I have to hand signal it to him like a baseball coach :spit:

Yeah, open a door when he does it and watch him fly through his roof!!!its quite entertaining.

 

[TeaBagger2006]

..... I can't post anything good, so I won't comment in your thread........

I lied! You been running that Ben gay like I told you:hug:

unplug the regulators

 

[DIESELMAFIAPER.LB7]

I always full flash lol and are you running both lb7 regs?

 

[SSchmi5519]

I always full flash lol and are you running both lb7 regs?

yea he is

 

[DIESELMAFIAPER.LB7]

Well piss there went one idea does coolant temp play a role like if its hot or cold make it worse?

 

[Hot COCOAL]

James im suprised? I think you should change out your fpr's to lbz fpr's i think you have the idea floatin round that is the problem, you will probably have to hear if from someone other than me though

 

[cafryer]

Why lbz regs you dont need them if you have dual pumps

 

[Chevy1925]

James im suprised? I think you should change out your fpr's to lbz fpr's i think you have the idea floatin round that is the problem, you will probably have to hear if from someone other than me though

its not worth the trouble. i hold rail all day long with two stocker pumps and LB7 regs. adding in LBZ regs opens the possibily of another issue or idle issues i dont care to deal with. Why fix what aint broke?



Update. tried a stock tune in it the other night, no difference. Met up with steve last right to fine tune the trans in and he saw what i was seein. at idle its running up to 10-14k now and pulling pw waaaaay back because of it yet commanded is asking for 5k. put the truck in drive and give a bit of throttle and starts dropping some. shut the truck off and turn it back on and its like i said before.

Ive never seen a stuck reg do things like this before and if i command max rail, it will hit it no prob. under WOT it will hit commanded no prob. only when at idle or coming down to low rpms will rail become an issue. Maybe my PPE control box is going?

Dan, ideas on testing it?

 

[paint94979]

its not worth the trouble. i hold rail all day long with two stocker pumps and LB7 regs. adding in LBZ regs opens the possibily of another issue or idle issues i dont care to deal with. Why fix what aint broke?



Update. tried a stock tune in it the other night, no difference. Met up with steve last right to fine tune the trans in and he saw what i was seein. at idle its running up to 10-14k now and pulling pw waaaaay back because of it yet commanded is asking for 5k. put the truck in drive and give a bit of throttle and starts dropping some. shut the truck off and turn it back on and its like i said before.

Ive never seen a stuck reg do things like this before and if i command max rail, it will hit it no prob. under WOT it will hit commanded no prob. only when at idle or coming down to low rpms will rail become an issue. Maybe my PPE control box is going?

Dan, ideas on testing it?

that would be my guess James... If I was you I would remove the dual pump kit and see if it changes

 

[Chevy1925]

that would be my guess James... If I was you I would remove the dual pump kit and see if it changes

ill have to find my spare old belt and see.

 

[LBZ]

It couldn't be your lift pump being on the edge of being too high of a pressure at idle could it? Maybe the load on the engine putting it in gear requires just enough fuel to keep your pressure against the FPR in check so to speak but in park it's not? Just spitballin here.......
Going back to what was said about running just one cp3 is a good start. Swapping regulators on the one that is still running in the valley to see if the problem comes back is the best way to check the reg too.

 

[Chevy1925]

It couldn't be your lift pump being on the edge of being too high of a pressure at idle could it? Maybe the load on the engine putting it in gear requires just enough fuel to keep your pressure against the FPR in check so to speak but in park it's not? Just spitballin here.......
Going back to what was said about running just one cp3 is a good start. Swapping regulators on the one that is still running in the valley to see if the problem comes back is the best way to check the reg too.

well i have a ADII and i have the reg adjusted all the way in but pressure is no higher than 14psi and has never given me an issue before. my FICM is bypassed as well so i know that isnt messing with it. If i get time tonight ill try bypassing the second cp3 and go from there.

 

[SSchmi5519]

Dan, not sure this helps at all with diagnosis, I've never dealt with 2xCP3 controllers etc.

In the log you can tell its not something that is immediately wrong, as it idles right at the desired MPA for a second, then slowly starts ramping up.

First actual climbed slowly to and then stayed at ~80MPA. Then we drove across the parking lot and though when on the throttle the actual psi drops to desired, when off the throttle during decel, the pressure starts ramping up real slow again...only this time to 101-105MPA.

From my initial observation it doesnt appear that a reg is bad or something that is causing faulty operation all the time, like if it had high psi all the time. Its just strange to me that it increases by like 1-2MPA every second with a real smooth curve.

 

[Dan@PPE]

Sorry I just saw this... Please call me 714-985-4825. my guess is lift pump pressure is too high, but I have a few other ideas if not. Thanks