stumbling/rough idle

washingtoncoastie · May 22, 2014

just recently started having some rough idling/bucking. it does not happen all the time and does not seem like it happens only under certain conditions. a background on the truck:

2003 excursion 7.3
170,000 miles
stock internals
tymar intake
stock hpop
stock injectors
bts trans
running premium blue 5w40 ~3500 miles on oil
recently added recommended amount of archoil.

i have some data logs, but haven't uploaded them yet. so on to my questions/problems:

1) at idle how much should my ICP fluctuate? at idle in park my ICP is fluctuating between 470-510. IPR duty cycle @ idle is 13.7%

2) at full throttle my ICP ramps up to 2850 psi but seems to fluctuate more than i think it should. it will bounce between 2700-2850, IPR duty cycle at full throttle is 40%. it never seems like the truck is down on power, the second i apply any throttle it acts as I think it should. is this fluctuation normal? my duty cycle doesn't seem excessively high.

3) the truck uses no oil, and as far as i have observed, has no oil leaks. i have not had a chance to clean everything with brake clean to verify this, but the spot it gets parked on my driveway has not a single drop of oil on it.
with all this said, i am leaning towards a bad IPR over a weak HPOP. does this make sense or am i completely off base here?

please forgive me is this isn't the clearest description, i just got back from being deployed and am in the process of moving, so there are tons of things demanding my attention and then this problem pops up. right before i will be driving from homer, Alaska down the ALCAN to Seattle with the family. i am just hoping that it is just the IPR and not the HPOP because i doubt i could get one shipped up here and installed before i am due to leave.

any help is greatly appreciated and i thank you in advance.

washingtoncoastie · May 22, 2014

right after i posted this i had a thought; these problems started about two weeks after i added the archoil to the truck. being that i already run a thin oil, do you think that maybe the archoil is making the oil too thin for the IPR to operate properly?

TARM · May 23, 2014

Check the IPR lock nut and make sure its tight. I have seen weird surging bucking issues when that becomes loose or falls off and the cover sleeve ( can't think of the correct name right now for it) can come off. Also it could be dirty etc. Personally if it ends up being that I think its just better to pay the money and replace it rather than try to rebuild or clean it. Seen a number that act up no matter what so for me I choose to save the grief and replace things like that when they act up.

Anyways one possible cause for your issues. Golfer usually comes along and he is very good at diagnosing these kinds of things as he has seen it all many times over.

washingtoncoastie · May 23, 2014

thanks TARM. I will do that.

mandkole · May 23, 2014

no codes, any starting issues? under what condition, or when is it most likely to act up?

washingtoncoastie · May 23, 2014

mandkole said:
no codes, any starting issues? under what condition, or when is it most likely to act up?

it just started throwing codes. it has thrown p1280 & p1000 a few times now. the last time it threw those codes and i tried to clear them, the second i pressed the button to clear them the engine shut down. i cycled the key and started it back up. it ran fine for about 5 minutes and then the check engine light came on and the engine died, no coughing or stumbling before hand, just stopped like i turned the key off. now every time i try and clear those two codes, the engine shuts off like i turned it off with the key. i checked the IPR nut and it was tight, i got about a 1/4 on it, but it wasnt loose by any means.
it has no starting issues, starts every time like it should.

washingtoncoastie · May 23, 2014

after tightening the IPR lock nut i have not thrown the p1280 code. but the p1000 code is always there. it comes back right after i clear it.
honestly im at a loss here. i just replaced the fuel filter and when you key on after draining the bowl it fills up quickly. i do not have a means to check the actual fuel pressure right now.
it rough idles right after you start it up. if you apply any throttle it revs like it should and when it settles down to idle again, it idles smooth. but if you are driving and completely let off the throttle it lopes....
would sticky popit valves cause this?

i ordered a new IPR through dieselsite.com. so i guess its a waiting game now. unless someone else has any insight into this. gonna try and get a video of it tomorrow.

TARM · May 23, 2014

Always mention codes you have when you post your issues. I typically expect if a person does not mention codes its becasue they do not have access to a code reader and thus try and work on other ways to diagnose the issue. Codes many times can lead you directly to the issue.

IF you look it up you will see its P1280 code is for ICP circuit low P1000 IIRC usually means it POST up or system self diagnostic check was interrupted or not completed for some reason.

Unplug the ICP sensor and see if the idle improves. Also look at the connector itself and see if its worn. If there is any oil on it that is a shore sign its gone bad. Change out the sensor and do not go cheap and buy one online or at a discount auto store. Get a OEM Ford of IH. It will likley save you grief down the road.

washingtoncoastie · May 24, 2014

Yeah, sorry TARM, I know that codes are always supposed to be mentioned. With everything I have going on I forgot to mention them. There is no oil leaking from the sensor. Will try unplugging it and see what that does.

Arisley · May 25, 2014

I thought a P1000 meant somebody had cleared the codes and the P1000 stays for a certain amount of miles or a certain amount of key cycles.

I know here, when my wife's car needed inspection, I replaced all the O2 sensors, cleared the codes. A P1000 code appeared. It would not pass inspection until the code cleared. Only way to clear it was drive.

TARM · May 26, 2014

Yes that is correct I think I just naturally disregard it. As my X sat all winter I actually have not been hooked up to AE for some time. Had to think about it. LOL

Well maybe the lock nut was the issue. Is it running better now or still the same issues just no codes?

Follow my last post if its still running badly.

washingtoncoastie · May 26, 2014

its still running poorly, still setting off those two codes. but it is like it has a mind of its own as to when it acts up. i have not been able to determine a specific condition or reason that makes it rough idle. it just does it as it pleases. the last two days it has ran fine, not a hint of a problem except the check engine light is always on and i have those two trouble codes. then this morning on my way into town i let off the throttle completely to slow down for a corner and it died like i turned the key off. i threw it in neutral and cranked the key and it started back up fine with no loping. it did this twice more, both times occurring when i let off the throttle all the way. sometimes when i clear the trouble codes the truck will shut off, sometimes when i clear them it makes it lope like the engine wants to jump out of the engine bay, and sometimes it clears the lope up and it idles correctly. but no matter what, both the codes immediately come back. honestly i forgot to disconnect the ICP sensor to see if that clears anything up. i will do that next time i start it up. just to be safe i ordered an ICP sensor, ICP sensor wiring harness from Riffraff, and an IPR, and a HPOP and IPR o-ring set from dieselsite.com.

lincolnlocker · May 26, 2014

TARM said:
Always mention codes you have when you post your issues. I typically expect if a person does not mention codes its becasue they do not have access to a code reader and thus try and work on other ways to diagnose the issue. Codes many times can lead you directly to the issue.

IF you look it up you will see its P1280 code is for ICP circuit low P1000 IIRC usually means it POST up or system self diagnostic check was interrupted or not completed for some reason.

Unplug the ICP sensor and see if the idle improves. Also look at the connector itself and see if its worn. If there is any oil on it that is a shore sign its gone bad. Change out the sensor and do not go cheap and buy one online or at a discount auto store. Get a OEM Ford of IH. It will likley save you grief down the road.

this^^^

also in my experience, thin oil with an additive that might make it thinner doesnt work that well in a 7.3.. I have tried all forms of oil and I still recommend 15-40 dino and if you cant get Schaeffers 15-40 then go with chevron delo 15-40 and if you feel the need to add something to it then add the Schaeffers moly ep treatment. it does amazing things in a 7.3 psd....

1280 code usually means the icp sensor is bad or there is a bad connection with it..some of the symptoms you describe with the lope and fluctuations are usually do to a bad ipr or icp sensor. could be one or the other..

personally I would start by changing the oil to 15-40 and see if it changes.

live life full throttle

washingtoncoastie · May 27, 2014

lincolnlocker said:
this^^^

also in my experience, thin oil with an additive that might make it thinner doesnt work that well in a 7.3.. I have tried all forms of oil and I still recommend 15-40 dino and if you cant get Schaeffers 15-40 then go with chevron delo 15-40 and if you feel the need to add something to it then add the Schaeffers moly ep treatment. it does amazing things in a 7.3 psd....

1280 code usually means the icp sensor is bad or there is a bad connection with it..some of the symptoms you describe with the lope and fluctuations are usually do to a bad ipr or icp sensor. could be one or the other..

personally I would start by changing the oil to 15-40 and see if it changes.

live life full throttle

i changed the oil out and put in delvac 15-40. i unpluged the ICP sensor and i made it better. so at this point im waiting on parts to arrive and we will see where i am at after that.

Thanks for all the help!!! i know this wasnt the most coherent string of posts i have ever scribed. :toast:

lincolnlocker · May 27, 2014

washingtoncoastie said:
i changed the oil out and put in delvac 15-40. i unpluged the ICP sensor and i made it better. so at this point im waiting on parts to arrive and we will see where i am at after that.

Thanks for all the help!!! i know this wasnt the most coherent string of posts i have ever scribed. :toast:

so by changing oil itself it didnt make it better?

live life full throttle

washingtoncoastie · May 30, 2014

lincolnlocker said:
so by changing oil itself it didnt make it better?

live life full throttle

i thought it did at first but then after running it for about 50 miles the lope came back. i got the icp sensor and the wiring harness in the mail today. hopefully will have them swapped out today or tomorrow.