surging and inconsistant idle

[OIIIIIIIO]

Hi

I've got an inconsistant idle (jumps from 600 up to 1000-1050 and then quickly back down) as well as surging while driving.

Possible diagnosis?

Bad turbo?
Bad oil controlling injectors?
Bad injectors?
Bad cam positioning sensor?
Bad crank positioning sensor?
Poor air intake (kinda "feels" like it's starved for air when driving between surges)?
Poor exhaust?
Bumpy ride and driver can't keep his foot still?

Any and all ideas wanted...

Thanks!
Patrick

[bismic]

What year model truck?
What mods?
What repair history?
Any codes (can get codes w/ no CEL)?
What are your routine maintenance practices?

[OIIIIIIIO]

I suppose that info would be helpful huh?

2004 F350, 6.0, auto, crew cab, 4x4, 90k miles

2" spring lift, Superchips economy program

No codes with Superchips diagnostic function

Recently repairs;
freed up siezed brakes in the rear...replaced rotors and pads
freed up siezed brakes in front...replaced pads...rotors were still good
replaced cam sensor
replaced exhaust pressure sensor
replaced air filter minder.

Purchased 2 months ago...have put on about 1000 miles. Came with a fresh Amsoil oil change. Run a fuel additive put I forget the brand off hand...though it's been mentioned on here a number of times...White bottle with red top...wish I could remember off hand...will have to go check...

Thanks for any help...

[hazard]

may want to pull the plug on the ICP sensor while its running and see if it smoothes out, if so, replace the sensor, your truck is a 2004 so it is below and behind the turbocharger which is a bearcat to get at. good luck.

[Logan]

Mine does it too. Not sure what it is. I have heard many different things. I hope to get mine on AE this weekend.

[bismic]

Originally Posted by hazard

may want to pull the plug on the ICP sensor while its running and see if it smoothes out, if so, replace the sensor, your truck is a 2004 so it is below and behind the turbocharger which is a bearcat to get at. good luck.

I agree! However - the late 2004's have the ICP on the passengher valve cover (maybe you will get lucky).

[OIIIIIIIO]

I haven't yet got a chance to check the ICP...my problem is intermittent so I don't think it would help much if I unplug it when I'm not having problems.

But...Some more info...
This problem, while it does occassionally happen when the motor is cold...it happens much more frequently when it's warm.

A mechanic friend was thinking it sounded more like an EGR issue...but wouldn't EGR issues throw a code? I didn't get one with my superchips...would another code reader maybe get one?

Thanks,
Patrick

[bismic]

With the synptoms you describe, the most likely candidates are:

ICP
IPR
High Pressure Oil system leak

[Robsr]

I need to stop fixing 6.0 liters and just start selling parts, I'd make a killing LOL!!!!!!!

[OIIIIIIIO]

Originally Posted by bismic

With the synptoms you describe, the most likely candidates are:

ICP
IPR
High Pressure Oil system leak

ICP - Injection Control Pressure?

IPR - Injection ...?

High pressure oil system leak...just thinking out loud...injectors controlled by oil...so if there's an oil leak in that system...the injectors aren't going to work properly...

Any tips on how to diagnose those if they aren't throwing a code?

ICP - pull when running rough...if it smooths out, replace it.

IPR - ?

HP Oil Leak...Look for oil...where abouts?

Thanks!
Patrick