Intermittent Rough Idle
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From: Washington
Intermittent Rough Idle
Wifes truck is having some issues. Its a L99, cclb, auto with 207k mi. All stock/factory as far as we know.
Its got what I would call a rough idle or maybe a "miss". It only acts up at idle, not on cold start, (though it doesnt matter if the truck is warm or cold),no smoke, no hard start, no lack of power, and no cel. She first noticed it when slowing down to a stop, it would run rough (shake, miss, etc..) but clear up as soon as you take off. Its always been intermittent. I drove it for the first time today while it was having issues, just drove a few miles and every time I came to a stop it would idle rough, take off and its fine. However when I parked it if I let it idle in gear then shifted to N it would idle rough, then back in gear (D or R) it would clear up, then P rough idle etc...
Seems strange to me, only thing that has been done was a new fuel filter that didnt change anything. I do have AE but with no codes I dont know what to look for as I've only used it a few times and its been quite a while. Any help is greatly appreciated.
Its got what I would call a rough idle or maybe a "miss". It only acts up at idle, not on cold start, (though it doesnt matter if the truck is warm or cold),no smoke, no hard start, no lack of power, and no cel. She first noticed it when slowing down to a stop, it would run rough (shake, miss, etc..) but clear up as soon as you take off. Its always been intermittent. I drove it for the first time today while it was having issues, just drove a few miles and every time I came to a stop it would idle rough, take off and its fine. However when I parked it if I let it idle in gear then shifted to N it would idle rough, then back in gear (D or R) it would clear up, then P rough idle etc...
Seems strange to me, only thing that has been done was a new fuel filter that didnt change anything. I do have AE but with no codes I dont know what to look for as I've only used it a few times and its been quite a while. Any help is greatly appreciated.
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From: Northern California
I usually start here https://oregonfuelinjection.com/cont...diagnostic.pdf
but the intermittent part to me says something wire related like a IPR pig tail.
but the intermittent part to me says something wire related like a IPR pig tail.
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From: Washington
No fuel pressure gauge. Others have suggested this as well but I struggle to see where it’s a fuel pressure/lack of fuel issue, again this is just a rough idle. Upon acceleration, or any use of the skinny pedal for that matter, it seems to clear right up. No vibes, no hesitation, no lack of power etc. Wouldnt a fuel pressure issue become worse as more fuel was demanded?
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From: Washington
I usually start here https://oregonfuelinjection.com/cont...diagnostic.pdf
but the intermittent part to me says something wire related like a IPR pig tail.
but the intermittent part to me says something wire related like a IPR pig tail.
Correct me if I’m wrong but if I unplug the IPR the truck will still run? And if it smooths out, it’s **** up?
FTE Remembers
Joined: Apr 2011
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From: Northern California
Pretty sure you are thinking of the ICP, I don’t think it will run with the IPR unplugged.
I recently had to pull my harness ( easy to do ) and go over ever inch of every wire. Harness week-spots are where wires branch off the trunk and the plastic armor doesn’t protect it and near the connectors.
I recently had to pull my harness ( easy to do ) and go over ever inch of every wire. Harness week-spots are where wires branch off the trunk and the plastic armor doesn’t protect it and near the connectors.
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From: Washington
Pretty sure you are thinking of the ICP, I don’t think it will run with the IPR unplugged.
I recently had to pull my harness ( easy to do ) and go over ever inch of every wire. Harness week-spots are where wires branch off the trunk and the plastic armor doesn’t protect it and near the connectors.
I recently had to pull my harness ( easy to do ) and go over ever inch of every wire. Harness week-spots are where wires branch off the trunk and the plastic armor doesn’t protect it and near the connectors.
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From: Washington
Ok so I finally got around to the looking at the truck. First thing I did was unplug the ICP to find it soaked in oil, knowing that’s not good I plugged it back in and fired the truck up. Thankfully it was immediately running rough so I unplugged the ICP and sure enough it cleared right up. And for the hell of it repeated the process, shut truck off (to get rid of ses light that came on when ICP was unplugged), plug in ICP, turn truck on, horrible idle, unplug ICP, idle clears up.
This tells me the ICP is bad, and is the culprit to my rough idle......am I wrong to assume that??
This tells me the ICP is bad, and is the culprit to my rough idle......am I wrong to assume that??
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