I presently have an issue with a bad ICP sensor, so it is disconnected, and the truck runs fine. I am careful with the truck and will replace the ICP/IPR this weekend. Here is another problem that I would really like someone to chime in on.

A few months ago, (while my truck was X3 tuned by Bill @ PHP), during first startup in the southern California chilly morning, about 60 degrees F, the truck would start right up. After idling a few minutes, the idle would go from a steady 750 rpm, and start revving and up and down, a few hundred rpms (some sort of oscillation). After another few minutes it would go away.

I read somewhere, that this was the beginning of a dying ICP sensor. Well, I tuned the truck to Vivian’s LooneyTune and the revving idle problem went away. She wasn’t sure what the problem was, and Bill from PHP never responded.

A few months later, the ICP died, and I disconnected it, so that I could continue driving my daily driver. This morning, after letting the truck sit from Thursday night to Tuesday morning, (Napa Valley Triathlon vacation weekend) it did it again; No ICP, and a tune which never caused the idle issue.

SO after a few minutes at a steady idle, it starting revving a few hundred rpms, up and down, for a few minutes, then stopped.

Does anyone have any idea what this might be? I am planning on replacing the IPR & ICP and all connectors this weekend, and was wondering if there is something else I should look at. Almost everything was replaced in this engine.

Last year, after a full rebuild, I had the High Pressure Nipple seals (all of them) die, just above the injectors. After this fix, it has been running good.

 

Try pulling the accounts fuse and see if it stops. You said it was cold if using defroster it's tied to the ac which cycles the ac pump. Does it do it when you have the defroster off?

 

I make sure that the AC is not on (no defrost nor ac max, or whatever) and it hasn't done it. I am pretty consistent about turning off the AC before turning off the truck. But until that one time last week, after keeping the truck off for 4 days, it has not done it. Now I did replace the ICP/IPR/EBP and all connectors yesterday, and it seems fine. I'll keep and eye on it and see if it does it again. I just started another post about all the stuff I did yesterday, and initially posted it here...... ooops.