Stalling

[bwvick]

I have a 2001 F350 with automatic transmission 205000 miles. For 2 weeks now i have been having problems with the truck stalling while slowing down to a stop. It started happening a few miles after filling up at a different fuel station that i normally use. i ran that entire tank out and filled up last week at my normal chevron station. At first i thought i just got a not so good tank of gas from the small cheaper station than normal, but now after filling with good quality chevron still having the problem.

Things i have done... replaced fuel filter... replaced cam position sensor.

The stalling always happens when slowing down to a stop when shifting down into lower gear. normally if i am sitting in park it idles about around 800 rpm. when downshifting to stop it will drop from say 1200 rpm down to 500 really quick when downshifting, then it will either ramp back up to around 800 or every now and then it will just drop out and stall. no check engine lights come on. i just put in neutral and it cranks back up, it cranks a little slower than normal after stalling. another detail if i am running the ac compressor the chances of it stalling increase, if i am not running the ac most of the times the rpm will drop down to 500 then kick back up to 800. another time it happens is if i am getting into a parking spot, if I turn the wheel sharp and push down on the petal sometimes it will stall. so it seems that it stalls if there is extra pull on the engine (power steering/ac compressor). However it has stalled when coming to a stop without me turning the wheel or having the ac on.

It has stalled once when sitting idle for a long time (15 minutes) with ac running. I don't know exactly how it happened then, i had ran into a store left it running and it was stalled when i came back out.

this is the only problem i am experiencing, when driving it powers just fine. i can get on the pedal and it runs fine. just a problem with slowing down to a start.

Also, another note I always use diesel kleen additive. when i thought i got the bad tank i doubled the dosage on that fill up.

So any ideas on what i could try next? thanks in advance.

[bwvick]

Also noticed today that it will exhibit the same symptoms if i am sitting in park, ref the engine up to about 1500 rpm. it will drop down below 500 rpm then jump back up to around 600-800. same as if i am slowing down.

[bwvick]

just an update in case someone sees this later.

I am 98% sure it is the icp (injection control pressure) sensor (126.00 from ford). I unplugged it yesterday and the electrical connector has oil on it which is a sign it is going bad. Also I drove home yesterday with the icp unplugged, and my problems went away. I have one coming today to replace with. I'll update later if this fixes my problem.

[ToMang07]

Yup, definately sounds like ICP to me. Hopefully that cures it!

[bwvick]

well just getting back to updating. put in a new icp and still have the problem. strange thing is that if i have the icp unplugged it does not stall (i do get check engine light). i also tried unplugging ebp sensor and still have the problem. sure looks and acts like icp problem. think i am going to have to take it to a professional, it is very frustrating and sometimes embarrassing

[bwvick]

This morning the truck would not crank unless i unplugged the icp sensor.

[ToMang07]

It may be your IPR then.

Whats the oil level in your HPOP res?

Does the oil pressure gauge come up quickly when cranking?

Do you have anyone near you with a good scanner that can scan it for you? The ICP you got, was it definately for the 7.3? Some sellers (like on ebay) try to sell the 6.0 ICP as the same as the 7.3 ICP and is is NOT the same.

[ridiculously_necessary]

in addition to the IPR. check your Injector harness for burns.

[bwvick]

have not checked oil level in hpop reserve.

yes, oil pressure jumps up to "normal" on gauge almost immediately after cranking.

definitely got the correct icp, got it from ford directly.

Don't really have anyone close with a scanner. Planning on taking it into the shop next week while I am off work.

Thanks for the input.

[bwvick]

Well I gave up and turned over to a professional. It was throwing a code indicative of a bad icp even though i had replaced it. He tried another icp, a new icp pigtail, hooked up wiring to break out box to test for shorts, tried a new pcm. Turned out to be a slightly bent pin in the engine wiring harness that was part of the icp circuit. So the solution was to repair the bent pin and works like a champ now. no longer trows any codes.