Major 7.3 Headscratcher

suprdzlduty · Sep 12, 2014

might check the harness on the drivers side valve cover...had one with a 1280 that wouldn't go away and would be intermittent rough idle, default icp, found the main harness had rubbed through by contact with the valve cover.

Marty · Sep 15, 2014

I have checked continuity on all of the wiring and also inspected resistance.

Marty · Sep 15, 2014

The last part of the high pressure oil system that I believe it could be is inside the injectors. I have a set coming from Swamps for the truck. I wanted to exhaust all options before pulling the trigger on a 1800+/- job for the customer.

lincolnlocker · Sep 17, 2014

Marty said:
The last part of the high pressure oil system that I believe it could be is inside the injectors. I have a set coming from Swamps for the truck. I wanted to exhaust all options before pulling the trigger on a 1800+/- job for the customer.

cps didnt change it?

live life full throttle

TyCorr · Sep 17, 2014

lincolnlocker said:
cps didnt change it?

live life full throttle

No kidding....im betting money on that...

Marty · Sep 22, 2014

chrischweiger said:
Crank sensor . Thats what my diesel buddy says.

lincolnlocker said:
cps didnt change it?

live life full throttle

TyCorr said:
No kidding....im betting money on that...

It's not the CPS.

This problem has to do with the ICP system.

New injectors did not resolve the problem either.

ghohouston · Sep 22, 2014

is this truck chipped? if so, have you run it without the chip?

Powerstroke Man 6.4 · Sep 22, 2014

ghohouston said:
is this truck chipped? if so, have you run it without the chip?

WHS ^ my old 7.3 had a weird idle. Does it idle like this?

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(click on the pic to view the video)

mandkole · Sep 22, 2014

That vid sounds like an AC compressor loading/unloading. If its anything like that, have you checked the accessories? AC compressor, alt work fine?

Powerstroke Man 6.4 · Sep 22, 2014

mandkole said:
That vid sounds like an AC compressor loading/unloading. If its anything like that, have you checked the accessories? AC compressor, alt work fine?

Nope it wasn't the AC or engine related it was the tuning. Set after set of tunes Dave at swamps fixed it with 200% nozzle tuning. (injectors were 160/100's) it also did the same exact thing with stock injectors and DP tunes. (come to find out it was the tuning) (A/C was off in the vid.) It even idled like that with factory PCM tuning (no chip and stock injectors). I thought it was the stock injectors. It had 300,000 some old miles on the injectors then I purchased the 160/100 's and idle same problem. So in the end the 200% hybrid nozzles tunes fix the problem. (Weird I know LOL)

Edit

I also purchased a new parts when I put the 160/100's in

HPOP T500
IPR
Swamps HI IDM
Airdog 100
CPS
UVCH and VC gaskets

lincolnlocker · Sep 22, 2014

Marty said:
It's not the CPS.

This problem has to do with the ICP system.

New injectors did not resolve the problem either.

but you did swap it out to rule it out right? cuz the issues you are having sound similar to the problems I have with my dually when the cps starts to chit the bed.....

live life full throttle

Marty · Sep 23, 2014

ghohouston said:
is this truck chipped? if so, have you run it without the chip?

It has some sort of diablosport in it but I swapped PCM's... with a stock one. No change.

Powerstroke Man 6.4 said:
WHS ^ my old 7.3 had a weird idle. Does it idle like this?

[/URL][/IMG]

(click on the pic to view the video)

The idle is way more erratic, but the RPM change is similar to that.

mandkole said:
That vid sounds like an AC compressor loading/unloading. If its anything like that, have you checked the accessories? AC compressor, alt work fine?

Drive belt has been off, no change.

Powerstroke Man 6.4 said:
Nope it wasn't the AC or engine related it was the tuning. Set after set of tunes Dave at swamps fixed it with 200% nozzle tuning. (injectors were 160/100's) it also did the same exact thing with stock injectors and DP tunes. (come to find out it was the tuning) (A/C was off in the vid.) It even idled like that with factory PCM tuning (no chip and stock injectors). I thought it was the stock injectors. It had 300,000 some old miles on the injectors then I purchased the 160/100 's and idle same problem. So in the end the 200% hybrid nozzles tunes fix the problem. (Weird I know LOL)

Edit

I also purchased a new parts when I put the 160/100's in

HPOP T500
IPR
Swamps HI IDM
Airdog 100
CPS
UVCH and VC gaskets

Stock injectors, stock pcm, stock tuning. Injectors have been replaced, PCM was replaced, tuning was stock on the new pcm.

lincolnlocker said:
but you did swap it out to rule it out right? cuz the issues you are having sound similar to the problems I have with my dually when the cps starts to chit the bed.....

live life full throttle

Just to please you, I just went and did it. Same thing, old cam sensor went back in.

:morons:

Arisley · Sep 23, 2014

Thanks Marty.

Have you ohmed out the harness?

dsberman94 · Sep 23, 2014

What's left to change? IDM? I was going to say do a buzz test but new injectors rules that out. UVCH and gaskets?

bluedge8 · Sep 23, 2014

any grounding issues? do you have a spare harness laying around you could try?

Bustedknuckles · Sep 23, 2014

Could it be a cylinder with low compression? It doesn't seem real logical but you've checked almost everything else!

lincolnlocker · Sep 23, 2014

this thing is ***ed

live life full throttle

Powerstroke Man 6.4 · Sep 24, 2014

I'm just throwing this out could you possibly command ICP a little higher at idle to see if it smooths out?

golfer · Sep 24, 2014

I'd like to see/hear a video with decent sound quality if possible.

Marty · Sep 24, 2014

Arisley said:
Thanks Marty.

Have you ohmed out the harness?

Yes, from all 8 injectors back to 42, to idm, to pcm. From icp sensor back to 5v ref, and ground, IPR the same.

dsberman94 said:
What's left to change? IDM? I was going to say do a buzz test but new injectors rules that out. UVCH and gaskets?

I have not changed the IDM but the truck passes buzz test and has continuity.

bluedge8 said:
any grounding issues? do you have a spare harness laying around you could try?

I haven't swapped another harness in but I thought I was certain that couldn't be the cause since I already checked resistance and continuity to intended circuit.