So I had a badly clogged EGR valve. So I replaced it since I could just warranty it.

Since replacing it I have a light misfire at idle, and some hard start issues since. The valve opens and closes as it should when commanded. I'm wondering if it's time to pull the intake off and clean it out.

As it is, the EBPS isn't used anymore, but if it or the EGRPS was clogged could it cause these kind of problems?

FWIW, the P0401 is always there. The P0404 and P1408 came via a KOER test.

No other codes, and I'm assuming I am just gonna need to do some major cleaning, but want to make sure I'm not missing something.

FICM, HPOS PSI is good warm and cold. Cranking and running. Everything else seems to be fine. Working on oil and fuel less then 1,000 miles old.

I'll take any ideas...

 

could have an issue with a carbon loaded egr cooler.

 

Yeah, I'm thinking it's all carbon loaded.

I was just doing some more testing though. The rough idle, deal. I was running a KOER test and it just quit. Like I turned off the key. So restart it watching the screen and it idles like crap for 10 seconds. The whole time my ICP reads almost 20,000 psi. Pressure drops to 6000 and it runs perfect then.

I'm wondering if I have a bad IPR causing my goofy idle issue and not the EGR system. Any thoughts?

 

It did pop a P2284 code after the stalls too. Did it like 10 times...

 

ICPv is .29 at KOEO

1.2 - 1.3 at idle.

No sign of voltage or pressure fluctuation before it dies though. About 3.8 volts after it dies and you restart it till it smooths out and goes back to 1.2.

Oh, FWIW the ICP sensor pigtail was fixed before. I checked it, looks okay but I am gonna redo them just to be sure...

 

Is this an early-2004 or late-2004?

 

Late build, ICP on VC.

 

Has the ICP sensor been replaced, or only the pigtail? For what it's worth, I have seen more than my share of trucks coming in with driveability issues that were directly related to poor workmanship in the soldering/re-joining of those wires. Does the truck react when you wiggle test the connection?

 

Sensor could have at some point. It's approaching 300k, so who knows. Wiring for sure.

I will be checking the connections too, but no, the wiggle test made no difference.

The thing that I don't get is the dieing, then running like crap. If I shut it off, it's fine. If it dies on it's own it's not. But I don't see a reason for the dieing on the scanner anyways.

When I replaced the EGR valve there was massive amounts of soot built up in the intake, so I attributed it to this. But then getting the P2284 changed it all.

 

Your ICP volts readings are a little on the higher end of things than I'm used to seeing. For what it's worth, a late-build 2004 engine should be idling at 580 psi in PARK or NEUTRAL at operating temperature, with IPR duty cycle at about 21 to 23%. I don't know where you are getting 20,000 and 6,000 psi readings from. I'm used to seeing ICP volts at around 0.24 at KOEO, so 0.29 does seem high. It might be worthwhile "borrowing" another known good ICP sensor to plug into, to see if readings change. At 300K MILES, I have to wonder what the condition of the main engine harness and FICM harness must be, with all the heat in there.

 

FICM wiring is pretty good, replaced that a while ago.

Getting the actual pressure readings of my Snap-on scanner. Which I just checked and is in Kpa. So before dieing it is at .89-1.05 volts at idle. 24% duty cycle, and about 4600 kPA (660 psi).

After it quits running and I restart. It runs like crap at about 20k kpa (2900 psi) and then looks as though it defaults to 6000 kpa (870 psi), cause it just sits there after that. Desired and actual. Then if I shut it off and restart it will go back to normal idle numbers again. Well, what seem to be normal for this truck...

 

David sounds like you have a Devil Child on your hands

20,000 ICP is high enough that Shouldnt the Saftey kick in The pressure releif so with that said maybe the ICP is jacked and if it really is that high the IPR is stuck closed isnt it

I also wondered about the EGR codes thinking that EBP and IAT2 at all carboned up causing those codes to surface

Oh the gauges wasnt on PSI Im with ya now

 

It's been a very trouble free truck really for me. But this is new and all of a sudden. I think I do have carbon problems for the EGR, and that's easy enough to deal with.

But this HPOS issue is goofy to me. Like I just corrected it's 20,000 kpa which is about 2,900 psi. So not to high, but why get that high after it dies, then default to 870? Then if I cycle the key it's normal till it dies again? Devil Child indeed! LOL

 

Oh is this your personal truck??

I thought that it was a clients truck

 

Nope, this is my truck this time.

I've worked on plenty of 6.0's but never run into something like this before. Hence the reason I'm here!