Icp question

[Dieselsmoke]

What would command an icp to be high at idle? I have a late 99 that has icp problems. It runs high at idle and as it runs. I don't have access to a scanner but had it scanned once and it read high according to mechanic. I idle at around 900 rpms until it throws the light then drops down to 600 rpms. I have had two new icps in it. I replaced the ipr and it seems to help but the problem still exists. It also causes the transmission to have a hard downshift from 4 to 3 but again disappears when cel comes.

 

[jtgf250]

Need to scan it to see what the light is for. Is 900 at idle when first started after sitting a while or all the time? The higher the rpm the higher the icp will be generally. Need to get it scanned really.

 

[Dieselsmoke]

I know it is the icp because i have battled it for awhile. It does not start off idling at 900 but once if passes 900 it doesn't come down. The truck is stock as far as I know. The truck used to lope almost like a big block with a huge cam. But since replacing the ipr it is not nearly as noticeable.

 

[Dieselsmoke]

I looked up on the paper and at idle my psi is at 750 or higher. I do not know the duty cycle.

 

[jtgf250]

Did you change the icp pigtail when you changed the icp sensor? If you got a wire mixed up when changing it, it can cause some weird stuff.

 

[Dieselsmoke]

I had it done at the dealership on the first one. I am thinking it has to be something electrical though. I had the PCM reflashed when I bought it. Could an old tune cause the PCM to call on higher icp pressures because I didn't swap it out the PCM but just had it reflashed. Is there anything else besides the icp ipr on that interact to provide oil pressure to the injectors?

 

[mandkole]

Is it still turning on the CEL? What are the codes? Clear the codes and see what comes back. The rail ICP is run by the IPR and ICP sensor. if you changed both of those, focus on the wiring if issue still continue. The only remaining issue is the injector oring bleeding pressure.

750psi is too high of a command for stock calibration. However, 750 is a default pressure if the ICP sensor is disabled somehow and it will throw a code.



If you haven't already done so, good reading...
http://powerstrokearmy.com/forums/showthread.php?t=1818

 

[jtgf250]

If you had it reflashed it will wipe out whatever tune may have been on the ecm. The only other thing I can think of off hand is the ebp valve. May be sticking or hanging. Check under the turbo exhaust housing and make sure the rod is still connected. The ipr is whats gonna affect the icp reading. The ebpv will cause it to rev up and act sluggish if sticking while driving.

 

[Dieselsmoke]

Thank you guys for the replies I will look at the ebpv when I get home tonight. As far as the cel it will clear itself when the truck turns off and sits for the evening. Then within a a few miles of driving it will kick on. When I first turn the truck on it will idle in the 4 to 500 rpms. It seems like once it gets over that 900 it doesn't want to come down. Also. It sure if this is related but I have to fan the throttle sometimes to get it to start and keep running when it is a cold start.

 

[Lethalthreat7.3]

Sounds like your having something similar to the issue i just fixed on mine. Had bad valve cover harnesses plus a bad connector on the passenger bank engine harness. Not easy to find.
Initial harness testing showed 3.2-3.5ohmns to each injector, most would say it was fine however after running for just a few minutes I found #4 increased to 8 and #2 went to 20. Changed the left vc harness. All injectors tested 3.0 on the left, 3.2 right.Started up and seemed to run better but while testing and holding the throttle at 1800 it seemed to miss every once and a while.
Retested harness at the engine connector. Found left side normal at 3.0 but right bank was reading 6.5 on all 4 and once the truck set for 5minutes it went back to 3.2 for each. Changed rt vc harness. All injectors tested 3.0. Reassembled and all injectors read 3.0 at the engine harness connector.
Started the truck and it was amazing how well it now runs.
No codes were ever set but while testing with AE i got it to fail a cyl contribution test on #2 twice but could never repeat/confirm the problem.
Sorry for the length but hope it helps

 

[Dieselsmoke]

Well my uvch is new on both sides since previous owner installed dorman ones. I will have to test plugs though

 

[Arisley]

Dorman UVCH is crap. Use Ford or International.

 

[Dieselsmoke]

I did haha

 

[Ron's Power Stroke]

the IPR and waste gate (down on the pedestal) share the same type of plug...did someone mix them up when plugging things back in??? also make sure the tin nut on the IPR is tight...

 

[Dieselsmoke]

Can you elaborate on the mixing up of plugs? I know where both are but I would think I would have more issuers than the high icp pressure.

 

[Ron's Power Stroke]

both plugs look the same.. if mixed up the waste gate is telling the IPR the wrong info...you wouldn't be the first one this happened to..you really need a scan tool..low fuel PSI can cause high ICP...right now its all a guessing game....

 

[bruce]

If the waste gate solenoid and IPR plugs got mixed up then it wouldn't run. A restricted fuel system can cause high ICP demand. It can't get the fuel it wants so it keeps upping ICP. If you hook a restriction gauge up to the inlet of the fuel pump and it pulls more than 5 or so inches of vacuum you need to clean the screens in the tank.

 

[Dieselsmoke]

Thanks guys for help. I will play with it this weekend or early next week. I know it needs scanned I am hoping I can run soon when I get ahold of a scanner.

 

[Dieselsmoke]

Thank you guys for all your help I pulled my codes this weekend and after changing the icp, i found out my eot sensor was bad and my hpop was getting weak. Since then I have sold the truck because someone wanted more than me. I appreciate all the help you guys have been but I am now strokelss.