Hello,
I have a 99 FLHTC Carbureted model. The bike has 135,000 on it and has never given me any problems till this year. When riding it I was getting the check engine light to come on and the bike would stall, it would restart but then stall. I checked a bunch of things and it would be okay, then act up again. I gave it to a service shop and they found nothing but some dirty wires. They clean up things and it was good for a bit of time.
I noticed that when the bike was pointed down hill it would happen in my driveway, almost like the gas was not flowing.
I was looking up on the ECM 23478-99, but can not find if that has anything to do with the fuel?

Can anyone point me to what the ECM does and if there is a way to test if it is faulty?

I am working on another bike, but I also want to purchase a RC51, so I have to figure out how to do both

Thank You!

 

You describe a 1999 FLHTC Carbureted model.
Basically it is a touring frame bike... Electra Glide classic with 135,000 miles.

It is hard to decipher what "I checked a bunch of things" means to you.
It is also hard to decipher what the service shop checked or cleaned.

Since you report that bike has a CARB and that you noticed that when the bike was pointed down hill it would happen in driveway then it might be loose tank liner or general trash in fuel tank.
Consider siphon of gas via gas cap fuel fill hole.
Try to see if you can use the greatest diameter clear hose in order to capture trash while draining tank.
Removal of fuel valve might be required if there is loose tank liner.

It does NOT read like it is an ignition module problem.

 

[QUOTE=pjfabrizi;22138474]Hello,
.
I was looking up on the ECM 23478-99, but can not find if that has anything to do with the fuel?
Can anyone point me to what the ECM does and if there is a way to test if it is faulty?
/QUOTE]


typo on the #
it`s 32478-99 and it has nothing to do with fuel delivery
I do not know how to test it,particularly since the fault is intermittent

I doubt a clogged tank would trigger a CEL
Fuel delivery COULD be related to the vacuum operated petcock
Are your vac lines 26 yrs old?

 

To ad to what IM has offered you...

If I may so bold as to offer a couple corrections, for clarity when you give info for us to decipher....

Your carbed bike doesn't have an ECM (electronic control module), those are for EFI bikes.. Your bike has what Harley calls an "ignition module".

Probably a typo, but your ignition module part number is actually #32478-99. The most recent version of that IM is #32478-99C.




They are no longer avaialbe from Harley. If you had an issue, you would need to get a used one or go to aftermarket like a Daytona Twin Tec, Twin Cam Ignition Module TC88.


Additionally, if you plan to do work on your bike, I suggest you get an HD Factory Touring models Service Manual #99483-99A. You can get one new from HD for $149.98. You can also get them used on eBay, for cheaper. Here's one for $78.

https://www.ebay.com/itm/36589868313...xoCsmIQAvD_BwE


I do not remember what year they started the separate Electrical Diagnostic Manuals, my oldest one is a 2001, but they are also very valuable when diagnosing an electrical problem.



Based on your limited info and description, it doesn't sound like an ignition module issue to me. The IM doesn't control fuel, only spark. The ignition module is not the first thing I would suspect. You really should offer more info. Remember, we are not present to hear, see, feel what you do. Plus we know nothing of your bike, or its history.

It's always good to describe how a problem surfaced, what you recently did to, and what mods are on, your bike. Then give details about what you (or a shop) did so far in trying to diagnose the issue. That will allow those of us who are going off solely what you are reporting, to make informed, intelligent suggestions...

 

I am guessing those fuel lines are that old. I do not remember changing them, but I could have.
Yesterday I did pull the ECM module, when I put it back on this morning and went for a 20 mile ride I did notice this.
The volt meter started was at over 13amp, when for a while it was below.
I have the check engine light come on when I was idling at stop sign\lights, but it never stalled and as soon as I brought rpm's up to 1,500 the light went out and it was running fine.

Thanks!

 

I have that manual.
I use this bike as a commuter vehicle from late February to end of December. It is ridden in all kinds of weather, rain\snow\cold\heat.
It started out of the blue in June when the temperatures got hot and the bike had been in traffic and at traffic lights. Was always fine in the AM hours, except one time when I got stuck in stop and go traffic.
What have I done?
Thought is was the heat sensor in the front cylinder, but when I looked my bike does not have one and I was those are only for the fuel injected.
I took off the car and rebuilt it.
I replaced the petcock with a no vacuum one ( ended up putting back the vacuum one as I am always forgetting to turn the fuel off).
I checked the voltage regulator and the all the connections
I checked the coil

When nothing was working I brought it to the my local shop.
I am not sure what they actually did, but they indicated that they didn't find anything but worn and corrodid wire under the fairing.

I have had issues with a oil pressure gage for years, but a shop looked at it an indicated the gage was bad.

 

My ‘99 Road King did the whole stalling thing when hot…tracked it down to the Crank Position Sensor.

Ended-up being an easy, inexpensive fix.

Might be worth you doing some searching on the symptoms of the sensor failure to see if they match your situation.

 

Hey Jumpman,
I had that go bad a few years ago, can't remember the actual year. The just cranked with no start, tracked it down CPS through this forum. I was thinking the issue was with the cam shaft sensor, but the local shop told me that wouldn't do it.

I am going to try the Crank Position Sensor and the also changing the fuel lines as they are old as the bike.

I did take the bike out on a ride after I posted not having an issues yesterday morning and sure enough I had the issues again, the temp was a bit, but there was local traffic. One thing I forgot to note, is when I have the problem the bike will also back fire.


I did look for that issue, would love to see photo's. but I couldn't find it. I am always impressed by talented, creative people, inspiring.

Thanks!

 

Check the 4 ends of battery cables.
Basically both ends of battery cables.

 

This report on the issue, especially the fact that it seemed to be worse when pointing downhill, made me think it was fuel related, not spark.





You are correct, you don't have a heat sensor, but you do have a MAP sensor that could need cleaning/testing. As well as a crank position sensor, but I believe you said you already replaced it. You need to look at your cam position sensor. See if it looks like it's oozing brown liquid. That is a sign it's toast.

Here are your sensors and their locations:




Since it originally sounded like the issue was fuel flow, I would have recommended a thorough cleaning and rebuild of the carb. Looks like you did that.
I hope you replaced the wear parts (specifically the float valve) and took the time to adjust the float properly. I also hope you used new seals on the manifold and carb when reinstalling. A leak there could cause your issues.

I am not a fan of the vacuum petcocks. I know there are a ton of them out there working properly, but I think they over complicate a simple device.
You said you replaced the vacuum petcock with a standard petcock, but then went back to the vacuum petcock because "I am always forgetting to turn the fuel off." That raises two questions.

The first is did leaving the fuel turned on lead to any consequences, like the carb leaking fuel when stopped? That would indicate a bad float valve (maybe even the seat). So I hope that got addressed during the rebuild

The second question is did you just reinstall the old vacuum petcock, or did you disassemble it and inspect the wear parts, namely the diaphragm?





There is some really good info shared in these above posts, that help us get a better understanding of the issue.


All your current issues, including the backfiring, could be an intake leak.

The rough running and stalling, could be a dirty/bad MAP sensor.



At this point, I would check the easy things first; clean/check the map sensor, check for intake vacuum leaks, and a visual check of cam position sensor.

Then if you only cleaned the carb before, I would do a complete rebuild (replacing all wear parts) paying special attention to the body of the carb. I would make sure there is no "baked on" dirt deposits in/around seats and ports. Sometimes there can be dirt deposits that don't easily come clean. I would also take the time to check and properly adjust the float.

After all that, I would start from scratch so to speak. I would run it again, take note of any symptoms, and start another diagnostic procedure based solely on the current symptoms, obviously with the current replacements/checks/adjustments in mind....

It all boils down to spark, fuel, and compression. You will need to find what is missing, and focus on that...

Keep us posted on your progress....