Idle variation, unknown cause
https://www.amazon.com/dp/B006NZTZLQ...I1YSTMJRV8GJJU
RPM X10, FIPW X10 to move up into the graph
The ICP is rock steady, FIPW only fluctuates minor.
Ford Trucks for Ford Truck Enthusiasts
I haven't read the whole thread, but I'll respond to what I glanced at:
We can't read a thread on communications in the 2017 forum and compare it with our trucks that were engineered on PCs with Windows '95.
The OBDLink MX or LX OBDII adapters are faster than we will ever need - and those are wireless (BT and WiFi). My AE USB interface I bought in 2010 is nowhere near as fast as my OBDLink MX Bluetooth, so we can't say one is faster than the other by default. The choke point is the electronics on the truck - that J1850 PWM protocol. Think back to '98 when they first manufactured the Superduty - high speed internet wasn't around, people were using modems with 56K baud (slightly faster than J1850 PWM at 43K baud), and AOL was the heavy hitter for getting online or email.
As for the variation on idle - I haven't seen one graph that focuses on IPR in high resolution yet. That's usually the bugger - it should be rock-solid when all is well. Is the fuel filter black?
Here's the same graph with IPR x100 to show/exaggerate the IPR.
Does that help?
OP reports Blue/White smoke when starting, up to 30 secs. No black smoke. Glowplugs and UVCH replaced in recent years.
I listened to a cold start and it failed to start the first attempt and cranking about 15secs, but we had the key on (reading AE) for a while first and that means the fuel pump would have been off (I always wonder about what happens when we let our GPs on for a while but the pump shuts off- does that extend startup times?)
When it did start on the second attempt, it started and seemed to run okay, not stumbling.
I would point to GPs, but that doesn't answer the stumbling idle. If it was the CPS, I'd expect the RPM values to be dropping out?
He did have a historical code P1670. We cleared it before the runs, but haven't checked if it or anything else comes back yet. Think a KOER test would be helpful? Doesn't that check the IDM?
Seth is gathering stuff for the Hutch mod, which should be done regardless, has the Racor on order.
Rotella T6 5w-40 Synthetic oil.
We went through a lot of Q&A and stuff on the phone. I think I hit the pertinent items. Seth, did I miss or mix anything up?
New glowplugs and Stancor relay last fall also.
I think you hit most of everything. If anybody has any questions ask away.
Thanks to everyone for there help.
If I divide the ICP by 10, I get 500 PSI - which is perfectly normal for idle with a warm engine.
The IPR would normally be somewhere in the neighborhood of 8% to 11% at idle (graph shows 10 times normal), with a lot of factors (like oil type, condition of HPOP, condition of injectors, etc...). "Most common" IPR is 9-10% at 500 PSI ICP. It's remotely possible the ICP is reading a tiny bit higher than actual, but all I suggest there is inspect and clean the ICP sensor connector. How does it start if you unplug the ICP sensor connector?
When I do a long charge on the GPs, the fuel pump cycles off - but the engine still cranks right up within the allotted 2 seconds without recycling the key.
Long cranks are frequently caused by the HPOP reservoir check valve leaking back (located on the block under the reservoir), wrong ICP values, bad injector O-rings, or very tired injectors. Synthetic oil helps with tired injectors, if it's of the tired injector variety. You can always pop the top and adjust your clearance on the injectors to eke out a little more life from them.
Seth, I'm sorry I haven't joined in on the party - work is absolutely killing me right now. I haven't been able to work on my engine for many weeks, and yesterday was a good example of why: 6 am on the job, serious problems arise at one of the plants, two PLC programmers and myself hang in there until 9:30 PM - and I'm still 45 miles from home. Get a call for online assistance at 1:00 am, then again at 5:30 am. I need a nap... or an epic cup-o-Jo.
Manipulating the graph position of the PIDs to overlay them should give a fair amount of info about the inverse relationship and fluctuations between IPR% and RPM.
Whether any conclusions can be drawn from that behavior or not, I don't know
It looks to me that either IPR is stumbling (IPR sensor) and the RPMs are bouncing in response to that, or more likely that the RPMs are stumbling due to fueling issues (air?) and the IPR is reacting to that stumble. Chicken and the egg. But we know the Hutch hasn't been done, so that increases the likelihood of the second, plus the fact that the Hutch is a good thing to do regardless and can either solve or rule out that possibility.
I guess it is fair to say this type of graphing shouldn't be considered "written analysis report quality" as I don't include any type of written explanations as I would in the professional world.
In my professional world I would graph the actual values, error values, flag the reliability based upon the anomalous values found in the log file, then use inset graphs without values to show that same relationship the overlay shows.
The individual data values are all available in the log file, if one needs to see a particular absolute value.
I would also point out that the graphs I post are only a snapshot of a particular set of data I find to be of interest or possible value. Others would surely find other sections of interest. Don't be shy, graph and share whatever you like, I'm ready to learn
I know Rich is a "numbers guy" and these kinds of things can irritate numbers guys, but I do think it is fair to say the info is easily understood by those who know the ranges of the values and such. I'm okay if you're irritated, Rich, especially with your current workload.
If I'm doing it wrong and the graphs are not of value, correct me. Just remember, I'm a little slow- you may have to repeat it a few times
IPR
ICP
EBP
Given the high mileage of this engine, why not replace at least the first two and check the condition of the EBP. I am not at all saying that the problem will be fixed. The IPR, ICP and EBP all work in difficult environments. Their performance is directly linked to proper running of these diesels and many have commented over the years-wow, the engine is... since doing the replacement.
That said, this problem has the symptoms of a marginal CPS/connection or air in the fuel. If the RPM info to the PCM is just suspect enough that the PCM is correcting for that bad info, the PCM may not see a problem with the circuit. And certainly air in the fuel damages injectors enough to warrant fixing the worst causes, even if not going the whole route with a Racor filter. Racor has a good writeup on their site about this common problem.
If I am wrong, keep the old sensor in the glove compartment.
Over the years, I have used the "list of most probable causes" method of troubleshooting. When a part is either suspect or old, why not replace. We have all read enough stories or experienced strange conditions ourselves to know that electronic parts by definition are flaky.
If I'm doing it wrong and the graphs are not of value, correct me. Just remember, I'm a little slow- you may have to repeat it a few times

I see that IPR/RPM in perfect sync with each other, and it makes me go "Hmmm. The IPR is compensating for something." IPR is a command, it is reactionary on a stock tune - so I don't suspect it leads the problem, but follows.












