99 7.3 idle shake and vibration

[pulltoy]

I have a 99 f250 7.3 powerstroke, stock. The service engine soon light came on and the idle is ruff and lacks power. No smoke. There were no symptoms before that problem, ran fine the day before. Changed fuel filter, oil filter, put power service additive but no difference. I don't have any way of checking codes.

[ToMang07]

Originally Posted by pulltoy

I have a 99 f250 7.3 powerstroke, stock. The service engine soon light came on and the idle is ruff and lacks power. No smoke. There were no symptoms before that problem, ran fine the day before. Changed fuel filter, oil filter, put power service additive but no difference. I don't have any way of checking codes.

Try unplugging the ICP sensor and see if that clears it up. I would guess it's either the ICP, IPR, or a UVCH Harness problem... but without the ability to scan it or run test, can't tell for sure.

[Deedsy]

I think I am having the same problem with my stock 99. Where is the ICP located and unplug it and plug it back in or leave in disconnected?

My service light comes on when starting and a little bit after while the idle is rough, and then the light goes off and the truck either dies or idles even rougher.

[ToMang07]

To test the ICP, unplug it, and start the truck, if it runs like normal, the ICP is most likely bad. (Unplugging it makes the PCM use default settings.) Also check it for oil in the plug. (Should not be any.)

[pulltoy]

Uplugged the ICP and idle got worse. After idleing a short time the truck turned off. In regards to the IPR and the harness how do I tell if those are bad. Cannot see how to disconnect the IPR harness at the sensor.

[Deedsy]

Mine got better but the service engine light stayed on but I expect that is because somethings not connected. As for the ICP is there a recommended brand or any will do? Thanks this was very helpful. and sorry for kinda jumping in on your started thread.

[ToMang07]

Originally Posted by pulltoy

Uplugged the ICP and idle got worse. After idleing a short time the truck turned off. In regards to the IPR and the harness how do I tell if those are bad. Cannot see how to disconnect the IPR harness at the sensor.

Don't uplug the IPR unless removing it, I was suggesting you check the wiring, any fraying, melting, etc.

Originally Posted by Deedsy

Mine got better but the service engine light stayed on but I expect that is because somethings not connected. As for the ICP is there a recommended brand or any will do? Thanks this was very helpful. and sorry for kinda jumping in on your started thread.

Yup, the light will come on because the ICP is not registering. If you are replacing it, use a OEM Ford ICP for your engine.