Hello all, was hoping for some thoughts on my situation...

The patient is a 1989 flhtcu (the most important thing I own, by far). She has had ignition module issues in the past but I will start with the current problem.

I ran some errands around town yesterday, stopping several times and she was running well. As I started her to move on to the next stop (getting gas) she was making a sound quite familiar to me...she had only one cylinder working. I turned her off, checked that the spark plugs were tight and the wires were in place (plugs and coil). Started her again, no change. I opted to take the back roads home and fortunately it was only about 4 miles.

The front cylinder did all the work to get us home. So I put my spark testers between each plug and wire although this time, I switched the front for the rear and hit the starter...now the only spark (strong) was in the rear.

The ignition module is an S&S HI-4N set to single fire with a single fire coil. Previously I had an issue with my Crane HI-4N so S&S sent me a replacement (free). About 2 years ago, while having a shop replace a pulled out cylinder stud (front) they diagnosed a faulty module. This was soon after the module was replaced so I called S&S and they sent me another one. They never requested the old ones back.

Despite the new (#2) S&S HI-4N being installed, she had a few moments of running on only one cylinder but then died--with no spark. I opted to look into the situation for myself and discovered the power wire to the coil was broken. I replaced the wire and all had been good (spark/ignition module at least), until yesterday.

My diagnostics so far have been to evaluate the continuity of all the wires...all have shown good even after excessive twisting of the wire in question. There was zero resistance across the coil.

One of the guys in the shop that put this module in had given me a spare single fire coil when she initially began having issues. However, I was told it may have issues with getting hot. I opted to take out the current coil and put this questionable one in. I kept the spark testers in place...she started right up and ran fine.

While running, I held a heat gun on the nose cone/module and she continued to run fine even with the temp over 300 F or 150 C (not that it doesn't get even hotter). She was thoroughly heated up and was still running well.

So, what else should I check? I suspect if I take her out for a ride, she will be fine at least initially. I can probably ride around my neighborhood for awhile but I doubt the problem is solved.

I do have a new dual fire coil (the module can run either). I also have the first S&S HI-4N that I suspect is fine. I highly doubt the module and the power supply wire were bad at the same time (although stranger things have happened).

Any thoughts? I know...this is that typical electrical issue!! But maybe I'm missing something specific?

Should I just throw caution into the wind and ride her like I stole her (the usual way)? Should I get some freon or other coolant and try that on the nose cone? I also haven't placed a jumper wire from the battery to the coil...but not sure what that will reveal, if the problem is intermittent.

I'm at a loss---so any help would be greatly appreciated!!

Sorry for the long post!! It has been a long day!
CatWoman

 

Was you having problems with the original ignition before u put the hi 4n on. You have probably replaced the plugwire to the cylinder that is missing?

 

Hi,

Thanks for getting back to me and so quickly!!

A few years ago, when I initially changed the OEM parts for the Crane HI-4N, yes it was running badly. Then she ran well with the Crane HI-4N for almost a year, but then was intermittently running on one cylinder (short bursts of it but then would go back to normal). When I called S&S had bought out Crane so they sent me a new HI-4N. This was the one that the shop replaced (with the 2nd HI-4N S&S sent to me). I had not experienced any issue prior to the shop reporting it was acting up.

So, it's a long involved answer but I can easily say, after I fixed the wire (power to the coil) I haven't had a single problem with the ignition module. I did replace the Stator and Regulator awhile later but the HI-4N has been problem free.
CatWoman

 

So basically the 2 hi systems r doing the same thing

 

I put probably 20,000 miles on the first HI-4N (Crane) before it was having problems. That is when I got the S&S HI-4N, I had been hit on my other bike so wasn't able to ride much but got probably 3,000 miles on it without an issue when then the shop (fixing another issue) reported it had a problem. This is when the 2nd S&S HI-4N was installed. It was having the same issues as the Crane HI-4N but when I evaluated the wiring, I discovered the wire that supplies the Coil with power was faulty. Since fixing that wire I've ridden around 10,000 miles before the problem last night.

Maybe these HI-4N systems don't go over 15,000 miles...which prior to my health issues, I was riding 20-30,000 a year.
CW

 

Maybe I misunderstood but it sounds like it was firing on only the front cylinder, you switched the spark plug wires, and the problem moved to the opposite cylinder. If when you swapped the spark plug wires, you moved the spark plug end, then you have a bad spark plug wire. If you moved the coil end, and the problem moved, then you have a bad coil.

A few years ago I picked a pair of screaming eagle spark plug wires and a screaming eagle coil on sale at Surdyke for hardly nothing and replaced my originals as a preventative measure since they were so cheap.

I hear you on health issues.....

 

Hi, sorry for sounding so vague, such is the case for me most of the time, but at least now I can blame it on my migraine headache (Ugh!).

When I got home, my thermal gun revealed the front cylinder was much hotter than the rear...so I knew it was the one that got us home. I knew I could eliminate the wires and plugs by hooking the coil up backwards or front to back, if the spark moved to the other cylinder...the problem was either the coil or ignition module. Even with the change in coils, both are now firing so the wires should be fine. Does that make sense?

The wires don't have to many miles on them, they were changed when I initially installed the original HI-4N from Crane. The plugs are new...or I should say, are about 2 weeks in use.

CatWoman

 

So it's fixed?

Regarding the migraines, take two Motrin and wash them down with coffee. I have suffered with migraines for many years, and that's my usual first line of attack.

 

I don't think it's fixed but cannot figure out what else to check. My neighbors would not appreciate my riding around and around the neighborhood so, it will have to wait until tomorrow.

Yes, migraines since I was 5 yrs old. Motrin doesn't really help mine, but I took Excedrin Migraine (2) and some extra caffeine. Ice pack of the back of my neck/skull can be helpful but you know what really helps---Riding. Often, riding my bike eliminates the headache for good but other times, stopping makes it almost worse. I have tried to get into a few studies on migraines lately but it seems they don't want people with PTSD.

CW

 

When you did this test were you running a single fire or dual fire coil?