1211 rough idle.
 

I was having a 1211 issue again, (idled fine, low power when warm), so I changed the oil including the hpop reservoir, disassembled and cleaned thi ipr, put everything back together and bled the oil rails. Then it idled good at start-up, but within a few seconds, sets a 1211 and begins idling very rough... but it has full power. I have since put about 1000 miles on it with no change. I replaced the ipr o-rings, then the ipr with another I had and it still idles badly weather the icp sensor is connected or not. Any ideas?

Have you tried a different ICP sensor? Any data on the ICP?

I have no data and no way to get any right now. I have a new sensor ordered, but I don't think that is the problem because it runs rough even with the sensor disconnected and a dummy value substituted in by the computer. It seams like a faulty sensor would cause just the opposite. If I erase the code, it idles good for a few seconds (presumably with information from the sensor),then sets the 1211 code, substitutes the dummy signal from the computer and runs rough. Am I missing something here or is there a problem with my logic?

I would have bought a scanner before I started throwing parts at it...

Thanks for the help.

Once you get a scanner on it. Watching ICP and DC% will tell a tale that you can't see without a scanner...

So far, I have only put $16.70 into it. I cannot afford to pay someone to scan it, and certainly not to buy my own scanner. I have used a scanner before and know what they are capable of...and yes I even have a pretty good idea how to interpret the data. I won't be putting the new sensor in until I am reasonably sure that is the problem. My other powerstroke is 200 miles away and I don't have the time or money to go get it to try swapping parts. Until I do, I am looking for someone who can help. Unless someone can tell me that it could still be the sensor, I have to assume that it is not building pressure or bleeding pressure... unless both ipr's are identically faulty.

If an icp sensor is causing a rough idle, shouldn't unplugging it smooth the idle?

Anyone have any thoughts?

well if the ICP is working properly, then un plugging it should make the idle slightly rougher. it get's rough since it defaults to the factory setting, when it's working , the PCM get's actually data so it runs better. when you un plug it. look in the plug, is there oil in the plug?

If it changes the idle by unplugging it, then all you did was discover that it is now running on it's default table instead of what is actually happening. And assuming is going to cost you more than looking at some real data...

It idles relatively smooth until the code is set and/or the sensor is un-plugged... then it idles VERY rough.

Because of an earlier blunder, everything under the hood is covered in oil. When my wife gets home with it from work, I will pull the plug and clean it then idle it some more to see if any oil shows up.

If the icp is NOT working correctly and is causing a VERY rough idle, unplugging it should smooth the idle somewhat...correct? I read somewhere that if it idles better with the sensor unplugged, then you definately have a bad sensor. This is not what is happening here. Is there some other scenario where a faulty sensor could give my symptoms?

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95powersmoker... I am trying to be polite. All you have done is state the obvious and confirm what I have already said. You are not helping. Please go away.