Please Help Random Ignition Loss

83 xj750
It was running fine i rode thru the rain and all of a sudden my ignition cuts out (lights all good just really weak or no spark) I've gone thru and re soldered every connection in the harness added extra ground to coil s
Separated headlight ground from pack and put that to the frame
Anyway it stops running randomly at speeds then won't turn over for a bit then turns on or shuts off then starts right up
Only thing is sometimes she'll ride great all day then it'll act up randomly

 

Definitely sounds like a ground to me... I'd trace them real, real carefully.

 

Rain.

Wet.

Cracked plug caps, cracked plug wires, or cracked coils (likely all three). Water causes the high side of the circuit to short to ground. The water that is trapped in the cracks can take a very long time to evaporate.

Fire it up in the dark tonight. See if you have a lightshow.

 

you beat me to it. I was going to say the same thing.

FU

 

Dang it! I missed the rain part. I was gonna say fuse box. I'm never gonna make it to "genius" at this rate!

 

It cut off three houses down thenI did see a small discharge from my right coil pack looked like it came from the ground wire Just before it started
(First time I noticed it hmmm )
!!K-MOE!!
So what your telling me is there's water in my coil packs? What should i do? Is this a fix or buy solution? And thanks so much i woulda never thought to try it in the dark Haha been attaching and re attaching wires for two weeks.

 

This is the perfect time to upgrade to dyna coils or accel's... They are cheaper than nos, and junkyard specials arent going to help you out in the long term.

 

Also acts up more on an up slope than flat ground if that makes a difference.

 

You got moisture in your coils.

 

So buying new ones is my only option?
I've been looking into the dynas for a while i guess now is the time to get it done. Thanks so much guys i really appreciate the help
Jmilliken thanks for the responses

 

The green dyna coils right?

 

Yes sir

 

If your budget can afford new coils then you should surely get them, but if you can't cover that cost right now your current coils can be repaired (so long as they test good aside from the cracking).

Clean the coils with denatured alcohol and seal the cracks with epoxy or black RTV. If the wires are cracked you can splice in new wires, and wrap the remainder of the old wires with self-amalgamating tape. The total cost of the repair will be less than the cost of one new coil.

 

i wonder if the ole salt in a bag trick would work like it does with other electronics...

 

i mean rice... been a long day.

 

It would, but is unnecessary. The coil body has to be clean for the epoxy or RTV to stick, and the alcohol will drive any residual water out. A fella could even use brake cleaner.

 

Yeah the salt will work...... Until everything rusts and corrodes

 

This can also happen when the bottom of the tank fills up with enough water over time to finally reach the petcock.....it doesn't just stop you all the time. Rather, it can just be at the line where depending on curve, hill, surge, etc....just enough water can get sucked in to cause stumbling, short-term stalling, momentary spark loss, etc..... The water can get in through the key hole, or past a cap that doesn't seal well anymore. Been there, done that.

Yes, as others said, it's more than likely that water got into a crack in one or both of the coils and THAT takes a long time to work it back out. Could also be water in the the tci, seen that enough....could be a wet headlight bucket, too.....

I would also HIGHLY recommend draining the tank, refill with FRESH fuel and put a dose of seafoam or star-tron to remove any other water that may still be lurking in your fuel system.

 

Dyna coils installed Man it runs amazing
Still the same issue
I'm going to change the tdi see if that helps

 

Loose fuses/weak clips in the fuse box

 

Hey! I said "fuse box" six days ago! Mebbe I am uh jeenyus!

 

New tdi fixed the issue guess there's something wrong on the underside of the chip
Gonna pull it apart and re solder everything to have a back up working one thanks a bunch for all the help

 

There is not any old bike that has only one thing that has to be fixed. One set of symptoms can have multiple causes, and sometimes it turns out that every damned potential cause is present on the machine.