Quick ICP question
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Tuned
Joined: Oct 2012
Posts: 391
Likes: 9
Quick ICP question
'02 7.3 PSD
This is obviously a bad ICP. I just wondered if I should check anything else first.
When I disconnect the ICP connector, the truck stumbles then quickly idles fine again (I know the HPO pressure defaults to 750 psi at this point). I did this test several times by shutting the truck off, reconnecting the ICP connector, starting the truck and disconnecting the ICP again and listening for the stumble. The problem is sometimes it stumbles, and sometimes it doesn't. I used a 0-3,000 psi gauge with steal braided line and tapped into the HPO rail on the head through one of the brass plugs on the rail. I watched the HPO pressure at idle while doing this test again several times.
2 different results:
-500 psi at idle, disconnect ICP, truck stumbles, then 750 psi idle
OR
-750 psi at idle, disconnect ICP, truck DOESN'T stumble, still 750 psi idle
Totally confirmed bad ICP.
The problem is intermittant and I haven't read anywhere that the ICP would fail like this.
But, should I be checking ANYTHING else before I replace the ICP? The connection is solid, not slopy or loose. All the wiring and ground is good (checked with a multi-meter)?
Thanks FTE, awesome forum!!!
This is obviously a bad ICP. I just wondered if I should check anything else first.
When I disconnect the ICP connector, the truck stumbles then quickly idles fine again (I know the HPO pressure defaults to 750 psi at this point). I did this test several times by shutting the truck off, reconnecting the ICP connector, starting the truck and disconnecting the ICP again and listening for the stumble. The problem is sometimes it stumbles, and sometimes it doesn't. I used a 0-3,000 psi gauge with steal braided line and tapped into the HPO rail on the head through one of the brass plugs on the rail. I watched the HPO pressure at idle while doing this test again several times.
2 different results:
-500 psi at idle, disconnect ICP, truck stumbles, then 750 psi idle
OR
-750 psi at idle, disconnect ICP, truck DOESN'T stumble, still 750 psi idle
Totally confirmed bad ICP.
The problem is intermittant and I haven't read anywhere that the ICP would fail like this.
But, should I be checking ANYTHING else before I replace the ICP? The connection is solid, not slopy or loose. All the wiring and ground is good (checked with a multi-meter)?
Thanks FTE, awesome forum!!!
Posting Guru
Joined: May 2013
Posts: 1,199
Likes: 2
From: Oklahoma
The 500 PSI at idle is normal, when you pull the plug the stumble might be caused by the PCM adjusting the IPR to flow extra pressure to compensate.
If you are seeing 750 at idle, your PCM isn't seeing the ICP at all and has already defaulted to the base level. Thus no stumble.
I don't see anything else to check, unless you can run your turck and watch your IPR percentage. That would be the cause of the jump when the ICP is disconnected, it is compensating.
correct me if I'm wrong here... Do you have oil in the plug of the ICP? Change it and be good more then likely.
If you are seeing 750 at idle, your PCM isn't seeing the ICP at all and has already defaulted to the base level. Thus no stumble.
I don't see anything else to check, unless you can run your turck and watch your IPR percentage. That would be the cause of the jump when the ICP is disconnected, it is compensating.
correct me if I'm wrong here... Do you have oil in the plug of the ICP? Change it and be good more then likely.
9 ECHO 1
Joined: Aug 2009
Posts: 12,467
Likes: 58
From: Missouri
This result indicates a functioning ICP sensor.
This result indicates a NON functioning ICP sensor.
If you are getting both of these results, it seems you have an intermittent ICP sensor. Are you getting a P1280 code BEFORE you unplug the sensor?
This result indicates a NON functioning ICP sensor.
If you are getting both of these results, it seems you have an intermittent ICP sensor. Are you getting a P1280 code BEFORE you unplug the sensor?
Thread Starter
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Tuned
Joined: Oct 2012
Posts: 391
Likes: 9
Thanks for the advise guys.
I pulled a few codes from the computer a couple of weeks ago. P1280 (ICP circuit out of range Low) wasn't one of them. I can check the print out and post them, off the top of my head I remember P1211 (HPO above/below expected value) which could mean a lot of things.
I'm chasing an oil leak which looks like it's coming from the HPOP plug or mounting gasket. Right now the fuel bowl is out and I'm going to pull the IPR for inspection, maybe even pull the HPOP for the non-servicable plug if it's leaking.
I did run the truck from 60-80mph with the gauge showing on the windshield.
Resaults were:
Chip in stage 1: HPO 2,750 psi 19lb boost 1,150 EGT
Chip in stage 5: HPO 1,900 psi 22lb boost 1,400 EGT
Obviously the oil leak is effecting things.
Once I seal up the oil leak and repair/replace any bad sensors, I'll run an actual duty cycle test. I bought a complete o-ring kit from RIff Raff, a few gaskets, the regulated fuel return and oil x-over line for safe measure in order to stabalize everything for a more accurate HPOP reading. I didn't see any oil in the ICP connector but I'll look again. Like I said the P1211 code could be a lot of things, even faulty injectors.
I pulled a few codes from the computer a couple of weeks ago. P1280 (ICP circuit out of range Low) wasn't one of them. I can check the print out and post them, off the top of my head I remember P1211 (HPO above/below expected value) which could mean a lot of things.
I'm chasing an oil leak which looks like it's coming from the HPOP plug or mounting gasket. Right now the fuel bowl is out and I'm going to pull the IPR for inspection, maybe even pull the HPOP for the non-servicable plug if it's leaking.
I did run the truck from 60-80mph with the gauge showing on the windshield.
Resaults were:
Chip in stage 1: HPO 2,750 psi 19lb boost 1,150 EGT
Chip in stage 5: HPO 1,900 psi 22lb boost 1,400 EGT
Obviously the oil leak is effecting things.
Once I seal up the oil leak and repair/replace any bad sensors, I'll run an actual duty cycle test. I bought a complete o-ring kit from RIff Raff, a few gaskets, the regulated fuel return and oil x-over line for safe measure in order to stabalize everything for a more accurate HPOP reading. I didn't see any oil in the ICP connector but I'll look again. Like I said the P1211 code could be a lot of things, even faulty injectors.
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
Stumbling at the transition from ICP plugged in and not is not an indicator of anything other than the PCM playing catch-up. 750 PSI at idle is perfectly normal for low oil temperature... a bad EOT sensor or loose connector to it could give you the exact same symptom.
Backing up a bit, what symptoms were you experiencing that led you to pulling ICP wires? Uber-low power with no soot? Real touchy throttle? Change in engine noise? High idle out of the blue?
Backing up a bit, what symptoms were you experiencing that led you to pulling ICP wires? Uber-low power with no soot? Real touchy throttle? Change in engine noise? High idle out of the blue?
Thread Starter
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Tuned
Joined: Oct 2012
Posts: 391
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Basically an intermittent check engine light with very little soot lead to a more occurring intermittent check engine light and more soot. That lead to a diesel shop running my codes and my diagnostic began. I've had the truck almost a year with an oil leak from day 1 of my owning it. I finally know enough about the 7.3 (I'm new to diesel's) to tackle the job. It has power & pulls fine. Just a check engine light, oil leak and a little more soot.
9 ECHO 1
Joined: Aug 2009
Posts: 12,467
Likes: 58
From: Missouri
If all youre seeing in P1211 that could potentially be caused by a chip or tuner if you have one, which I see you do. I dont know if the banks will throw that code or not. But that doesnt mean dont fix your leaks. Tugly and I will both stress how important it is to get your truck up to snuff before trying to push the limits.
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Tuned
Joined: Oct 2012
Posts: 391
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Well understood sir. I keep the tuner on level 1 almost 100% of the time. I towed my boat a few times & chipped it to 2 but that was it. I couldn't bring myself to chip it to level 6 as instructed when testing the HPO pressure. Thank you for the input.
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Thread Starter
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Tuned
Joined: Oct 2012
Posts: 391
Likes: 9
Oh BTW, ther were a few more codes. A few injectors read high to low side open, like I said I don't have the print out in front of me. I think if I remember correctly if they are all on the same bank that could be a loose UVC harness, I could be wrong though.
For me since I'm diving into this for the first time I'm tackeling one step at a time. Oil leack, sensors & wiring first. If I still get the codes I'll run through an HPOP duty cycle test & go through the injectors.
For me since I'm diving into this for the first time I'm tackeling one step at a time. Oil leack, sensors & wiring first. If I still get the codes I'll run through an HPOP duty cycle test & go through the injectors.
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
I'd get that UVCH soon. A fellow member didn't catch his and the right side of his engine died while on a winter vacation. A few hours under the hood with snow falling fixed the truck right up, but that was a miserable time to do it.
I used to get a CEL every time I got on the throttle hard, I was making more boost than the factory planned on (over 27 PSI). I changed a lot of hardware and I no longer get that particular CEL.
I used to get a CEL every time I got on the throttle hard, I was making more boost than the factory planned on (over 27 PSI). I changed a lot of hardware and I no longer get that particular CEL.
Thread Starter
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Tuned
Joined: Oct 2012
Posts: 391
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[quote=Tugly;13540487]I'd get that UVCH soon. A fellow member didn't catch his and the right side of his engine died while on a winter vacation. A few hours under the hood with snow falling fixed the truck right up, but that was a miserable time to do it.
Point taken, I'll pick up a set from the stealership today after work. Knowing my dumb luck I'd have an issue with the UVCH at the worse possible time. Thanks!
Point taken, I'll pick up a set from the stealership today after work. Knowing my dumb luck I'd have an issue with the UVCH at the worse possible time. Thanks!
Thread Starter
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Tuned
Joined: Oct 2012
Posts: 391
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So it's zero dark-thirty (I have to be at work in a few hours) and so far I've found a few gremlins. Both HPOP fittings were loose (I could almost unscrew by hand initially) which would account for my oil leak, and the driver's UVCH 9 pin connector was not snapped in. Thank god I found something, in this case a few somethings. I'm not through with the installing everything yet but at least I'm getting somewhere.
Thread Starter
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Tuned
Joined: Oct 2012
Posts: 391
Likes: 9
Absolutely true about the weekend wrenching worrior. I have 3 children the oldest is 6. The only time I really get is at night once everyone is in bed
.
Tugly-
I've been using this forum for about a year and it's by far the best for helpful info & tech. In that time the majority of usful info & friendly threads have had plenty of feedback from you. I'm sure you've delt with this seemingly simple issue with countless memers, so thanks for your taking the time to help one more with it.
.Tugly-
I've been using this forum for about a year and it's by far the best for helpful info & tech. In that time the majority of usful info & friendly threads have had plenty of feedback from you. I'm sure you've delt with this seemingly simple issue with countless memers, so thanks for your taking the time to help one more with it.