[Chadwick46]

I've been doing a lot of reading and cannot seems to find an answer. Most of the time my truck starts and runs fine. On occasion it will not start unless cranked 3 times or will start and run like it is missing a bunch of cylinders. Usually shutting it down and restarting it will clear it up. Sometimes if I let it run it will clear up on its own. I recently added an Edge Insight CTS 2 to monitor it.

The ICP values always seem normal. 600ish at hot idle all the way to 3900 under hard acceleration.
The IPR values on the other hand are questionable. When they are at 20-25 at hot idle the truck seems to run fine. However, sometimes (becoming more frequent) the IPR value will be 14% at hot idle. When this happens the truck has very poor acceleration. Seems like there is no throttle response until almost 1/4 or 1/2 pedal. Also this seems to be when the no start occurs. ICP values are still ok.

So the question: Should I be looking for an HPO leak or something else?

The truck is a 2006 6.0 Crew Cab Long Bed. Stock except a rebuild FICM with +40 hp from FICMrepair.com.

Thanks

Chad

 

[ritschner]

The IPR duty cycle should still be in the mid 20's range when hot. The ICP sensor is used to control the IPR duty cycle. The PCM is reducing the IPR duty cycle because it is probably receiving a high pressure indication from the ICP sensor. I would check the ICP sensor for oil in the connector and probably replace.

There is no indication currently that you a HPO leak. So, the next question that is unrelated to your issue is, Has the STC fitting on the HPOP been replaced? If not it should be since it will eventually either manifest itself in no/slow hot start or worse yet, leave you stranded.

 

[Chadwick46]

Thanks. The STC fitting has not been replaced as far as I know.

Interestingly enough when i started the truck cold today the IPR was low. Once driving the engine seemed to surge a little and act as if i was letting off the throttle, which was not the case. Once on a straight road i held the rpm around 3800 (almost wot) for about 10-20 sec. Never had another issue the rest of the day. Including interstate driving and multiple start stops. Really strange behavior. Would almost be better if it just quit completely!

 

[Torched]

You said sometimes it takes you a few crank overs to start?

Best way to check for icp fault is to remove it and start ur truck four or five times. If it takes you only one crank to start it then it is your icp.

 

[Torched]

Alot of the time, censors are the culprit. But id get your high pressure leak looked at too.

 

[Chadwick46]

Ok. Thanks.