That was informative and entertaining. In my line of work, we called the pick-ups, monopoles and they were notorious for failure and the first thing we would change out.
Thank you for that video - it was very informative.
The entertaining part was - this -
"Yaw'l, heeeer's how to check the cooool. Naw dat we all dun wit that, I'm goin up to the housss e'n get me a beeeeer." Too funny. But they guy seemed to know what he was doing.
You awl don't neeeeeed thet fancy equipment....No sir e... too funny.
At least his bike is fixed while mine sits on its duff.

HD shop is closed today, so no parts for me yet.

Oh - I see there is more than one video - I only watched the first one ! Thank you Mr. J !

 

In one of his vids I think he talked about being an HD mechanic. Down to earth guy with some good info without using expensive tools. I think your on the right track with the crank sensor. It's where my focus would be in your journey, if not keep working on it. Was told once "these bikes are like old farm tractors, they just keep running with a little maintenance".
Good Luck

 

For anyone following this for info.
The CPK is on the front of the engine case, right by the end of the oil filter, one bolt. The CPK electrical connector is under the Reg/Rec bracket, up front. Easy to remove and get to.
The book says the CPK electrical connector is located "Under the Cam Cover", that is not correct. From that connector, it runs along the inside of the frame tube on the right side, under the cam cover, and into the harness by the rear brake switch, and goes up behind the oil tank, behind the battery to the ECM connector. I will verify again, but I think it was pins 10 & 11 in the connector.
All places to inspect for damage when troubleshooting.

I used the video guys' advice and did the cranking non-running check with the Fluke meter. 2.7V AC solid. Used a heat gun and heated the CPK, while I installed and tried it again.
Solid 2.7V AC. I believe he said it should be 2-5V AC, and the one he was checking was about 1.5V and thought it was about to go bad. So maybe I found the problem?
I did not do the OHM check statically like he showed. I can do that this morning.

I was really hoping for both a lower voltage like he shows, or at least for it to drop out when heated. Did I replicate the heating as well as with the engine running? Hard to tell. But a little disappointing. Still hoping to find the actual culprit.
I still think this time to replace the CPK, but a little scared that it might be pointing to the ECM....damn. You would surely not think a bike with 24k miles in mint condition would have either of these items fail.


Yes, they are built like my old Ford 8N, but a lot more to them when they break down.

 

As I re-read your posts I see you talk about replacing the tank internals on the FI system. There's been several posts about ethanol fuel making the internal tank lines brittle which I'm sure you know. The regulator housing is something to check also for cracks. If it's cracked it's not going to pressure correctly. I wouldn't buy anymore parts for now. I'd be going back to the tank internals and double checking everything's good Frustrating as it may be doesn't hurt to recheck.. You've done a lot of troubleshooting but somethings getting missed. Start with the simple stuff first like the fuel fitting under the tank. If that fitting has any gaps it's not going to stay running. If the crank sensors good move on.

 

I did all the internals a couple of years ago. I did a pressure check on the system a few days ago, and it's solid. 58 psi running and next to zero bleed down after about a 1/2 hour or more. Primes instantly and holds. Don't think my problem is there. I did an inspection of the regulator and even a pressure check when it was all apart, and it checked fine, so I did not replace it. I do have a new spare now if it comes to that or I need it.

The bike has never seen ethanol. Always Prewm-Zero eth. The only thing that was actually bad was the filter pick-up screen. But it all got replaced. I thought maybe the press reg was the issue, but the pressure checks look to be excellent.

This has been a very mild and only occasional problem of a "Miss" for a long time, and just got worse all of a sudden - Like a sensor finally gave out.
Heading over to our HD dealer and getting the CPK and plug wires tomorrow. I want the OEM wires just for the heck of it, as I am not certain the braided steel wires are not also maybe messing with the Ion sensing system - I don't see why they would - but I want to have a backup.
I do appreciate the input.

 

Update - I'm screwed...
New battery = same condition. [ wanted it anyway ]
New CPK = same condition. Old CPK read 2.6V AC. New CPK reads 4.65V AC. While dry cranking. Thought that might be it = Nope.
New OEM plug wires = same condition. FYI - The Steel-branded wires I made appear to have no negative influence on the bike's electrical system for anyone who wants to run them.
OEM coil ohms out to spec. Replaced with what was supposed to be an OEM NOS unit = same condition.
New Fuel Injectors last year = same condition.
Fuel System Pressure checks all looked perfect.
All intake checked for air leaks - None found.
IAC & Air intake sensor, were cleaned and appear to be functioning as they should.
No codes.

I just don't get it. I knew these last parts were as much hope as actually being the problem fixer.
I am at a loss for where to go next. ??? ECM ? How can an ECM of a very low mileage bike be bad already ? I am out of my zone in that ECM area also.
Now, the bike did have a dyno-crap piggyback unit on it when I bought it, I removed it back when this misfire issue originally started. The cables, the laptop top, and everything required to try and use the DJ POS are just not available anymore. So it was less than useless, so I removed it and had the HD shop re-flash the OEM unit to OEM specs.
Could that thing have ruined the ECM ? Can you buy an ECM aftermarket that replaces the OEM unit ?

I swear, this bike will be the death of me, and it won't be from getting run over.

 

It could be the ECM, whether it was "ruined" by the tuner or not. Not sure what else it could be...

Did your bike run after the dealer flashed the OEM ECU to OEM specs.... ?

The replacement HD ECM for your bike, 2002 EFI Fatboy, is now part #32534-11. It still shows with a price of #429.65, so it should be available from a dealer. Then they would have to flash it to your bike, unless you know someone with a TechnoResearch Centurion Pro or Diag4Bike tool.

I would check the ECM, per the procedure in the Factory Electrical Diagnostic manual before spending that money...

Good luck, & keep us posted...

 

After I took off the DJ piggy and they reflashed it, it seemed fine for just a short while, and there would be that occasional hiccup again. So no, the flash did not fix it.
I thought about throwing the DJ pig back on at this point and see what happens - I have zero to lose now.

I will look at the troubleshooting guide for the ECM. No, I do not have access to the special equipment for a new ECM programming. I did read that in the book about when the TS guide comes to the ECM "replace" it states that it has to be programmed. Is that a one time when new thing or any ECM, even a used one, put on a different bike?
Going through the flow charts in the TS guide - It points to the ECM after the other items I have done. My parts book shows 32612-01A, so the number you stated must be an updated Pn. and version. For that kind of money, isn't there some of these units that are programmable that completely replace the OEM unit?

22,883 miles and bad - that sure does not look good for HD. Really bummed over here....

 

Here are all the electrical controlling items listed as making the engine run.

MAP
IAT
IAC
VSS
TP
TSSM
CPK
ECM

So, there is one thing sticking out at me that I have not done more than a visual or replaced. The MAP sensor. That might explain the cough in the intake, especially when first run and cold. I used to attribute that to a lean burn while warming up - but maybe it has been going bad?
IAT & IAC were cleaned, and that is about all I can do with them. Bad ? Could be I suppose.

Still hard to grasp that such a low-mileage bike, not subjected to high heat, could cause a sealed TSSM or ECM to fail. Slowly fail. So those seem like stretches to me. But hell. I am at a stumped point right now.

I see lots of used ECM's on eBay, but they are quite expensive for a used item, most with far more miles than mine has on it. Man, yard art is looking better all the time.

Annnnnnd, then there is that nagging feeling I missed something and it's fuel-related. Can it be? sheeets man, I don't know anymore. Pressure checks looked great, everything points towards electrical, but maybe I missed something. Stupid bike, I want to love it and give it a safe home, but it just keeps pizzing on me. Back to the pound, you mutt.

 

Don't just focus on the 22K miles... the bike is also 23 years old. Time can take its toll.. I'm learning that as I get older.. but I also have a crapload of mileage on me...

I don't mean this to be critical, but to point out a learning opportunity... If you throw parts at an engine, instead of finding the actually cause of your issue, you can get all caught up in an expensive and seemingly never ending chase to guess and accidentally replace the offending part. The bad part about this technique is not only cost and time, but it IS possible to replace a good part with a bad new part. It does happen once in awhile. That will just complicate the diagnosis process.

I have done my share of parts changing. Only in the last 10 maybe 15 years have I been able to discipline myself to go systematically and one step at a time. It takes practice and discipline. Even still, I sometimes take a short cut, but I'm much better than I was...

Codes are nice to have, diagnostic tools are excellent short cuts, but it all boils down to fuel, air, compression, and spark. I fixed a lot of engines without any code readers or diagnostic tools. You probably should start looking at this issue old school..

FUEL: You have checked the fuel pressure, so the tank inners are functioning properly. Only thing left fuel related are fuel line to fuel rail, fuel rail, and injectors. You could check the fuel line for internal delamination, the fuel rail injector and fuel line o-rings for leakage, and then have the fuel injectors tested for proper operation. That would rule out the fuel system as having any part in your issue.

NOTE: I remember you asking questions on an old thread of mine, about the early Twin Cam fuel injector issue. Namely the brown band #27609-01 injectors being updated around 2004ish to the white band #27609-01B injectors, both 4-hole injectors. This issue is not related to the service bulletin, M-1185 dated 2/20/2006, about the fuel injectors in 2006 Big Twins. The issues noted with the early brown band injectors were usually low rpm fueling issues. Most techs said if not experiencing surging at low rpm, or erratic fuel delivery, no need to change. Did you ever upgrade your brown band injectors? If so, did you use the HD part #27609-01B, with a white band?


COMPRESSION: You could do a compression test to be sure, but I don't remember reading anything that could be compression related.

AIR: I suspect you have seen or specifically checked that your air filter isn't all blocked up and/or unusually dirty. Have you checked for intake leaks?

SPARK: So after the above reviews on your engine, it will be prudent to suspect your problem is electrical.


At this point, anything you consider replacing, I would actually check that part to make sure it is below spec or has failed altogether.

This is where that Factory Electrical Diagnostic Manual you have will be worth its weight in gold. Refer to it, and trust it. When I was a new scuba diver (39 years and over 500 logged dives ago), it took me many dives and a lot of grief to finally realize, when underwater, I need to trust my compass. I was good at geographical navigation, but I was reminded often that I didn't know better than my compass..

I have to admit I am curious as hell as to what this issue is.. If you were closer to San Diego I'd say bring to my house, put it on my lift table, and let's start from the beginning...

So keep us posted with any future checks and/or progress...