Hey all, so my brother has had the FJ for a few days while his bike is waiting on a new tire. Today, while we here in Phoenix are having a rare rain, he left it out all day, getting poured on. Now, the bike wont turn over. The motor will turn when i hit the start button, but it doesnt sound like the starter is trying to catch. I looked for a short, and the positive battery terminal is shorting against the frame. I figure it will likely be fine once it dries out, but what would cause this, and how can I prevent it from happening again??
Battery voltage is likely very low, possibly drained. Get that positive post clear of any frame touching.
Yep
http://www.fjowners.com/index.php?topic=3292.0 (http://www.fjowners.com/index.php?topic=3292.0)
Quote from: ZOA NOM on February 22, 2019, 10:16:03 AM
Battery voltage is likely very low, possibly drained. Get that positive post clear of any frame touching.
Sorry, poor wording. The terminal is not actually touching the frame, nor can i see anywhere where the wiring is shorted to the frame. But my ohm meter still says that there is fault on the positive side, to the frame of the bike.
....and the fun begins... :dash1:
Maybe this
http://www.fj1200.info/Engine.html (http://www.fj1200.info/Engine.html)
Confirm your ground wire is tight at the back of the motor. You probably had it loose when you were working on that oil leak.
Randy - RPM
:Facepalm:
Sparky, that was my thought, that maybe the coils just got wet. Randy, thanks for the tip, I will check it out for sure. Pat, once it dries, I'll chase that short down if it still exists. I'm not looking forward to it. Dave, not sure which part you are referring to haha
I've bought nearly every set of FJ coils from wreckers I come across as spares. 1 in 3 won't work wet. 1 in 5 are just old and buggered.
Coils can go off like a prawn in the sun. On day they are fine, but one little teensy bit of rain and they're gone. Warm up, dry off and they work again.
It is great to have working coils as swapperoonies when diagnosing shitty fucking electrical gremlin c*nts.
I've been learning hard these last few years about different FJ systems, electrics for me are still for magicians. (Al, where's your smoke bomb? :sarcastic:).
Of recent experience of my incompetence I discovered the importance of 'the grey wire circuit'. Mate, obvious things first (and you seem to know what to do with a multimeter), I recently had the grey wire to the tacho intermittently short (my fault) and it dropped a coil. Being wet I'd follow the grey wire after the mains are ruled out, or even just disconnect the instruments plug. That will localise the fault to only half the loom. The bike will start fine with the instruments unplugged.
Troyskie has some excellent advice on coils. Most from breakers are bad. There is a reason for this and why they are affected by moisture. The location of the coils on our bikes exposes them to a lot of engine heat. This heat degrades the plastic the coils are embedded in. It also causes the plastic to shrink and then crack. As our bikes age the plastic goes through many heating and cooling cycles and eventually the cracks allow water in which shorts out the coil. Sometimes allowing the coils to dry out will return them to working order. Sometimes exposure to water many times will corrode them and they will not work dry or not. Testing the impedance with a volt/Ohm meter on both the primary and secondary is a good way to see if they work. These values are year specific and are slightly different among years. Swapping coils is also a good way to see if you know you have a good one that works. As time goes on we will all have this problem as age and mileage increase. Thank goodness there are aftermarket coils available.
As Troyskie has said the grey wire that runs from a coil to the tachometer could be shorted which would short the coil too.
Dave
On a US 84 fj1100 the wire from the tach is the orange wire and affects coils 1&4
Darn US colour changers! :crazy: :sarcastic:
What about coils 2 & 3? :sarcastic:
Quote from: Troyskie on February 23, 2019, 03:41:54 AM
Darn US colour changers! :crazy: :sarcastic:
What about coils 2 & 3? :sarcastic:
coils 2 and 3 are the grey wire,and go straight to the ignitor unit, according to the wiring diagram in my Haynes Manual
I have no idea why the US bikes use the orange wire for the tach and every other bike uses the grey wire .
Quote from: T Legg on February 23, 2019, 09:10:21 AM
I have no idea why the US bikes use the orange wire for the tach and every other bike uses the grey wire .
The tach/coil wire is Grey on the US spec 1989 models.
As an added note. Pull the left side engine cover, moisture has been known to get in there and cause issues with the rotor and ignition pick up.
I saw this happen at a rally last year on another members bike while riding in the rain.
Fred
Hey all, so the bike started up (albeit not well, i had to hold open the throttle otherwise it would sink and die), so i have it home now,and i will be looking into everyones suggestions this afternoon.
Very good point Fred.
On the way to the Harrietville Oz rally I ran over a largish stone and knocked a 15mm chunk out of the bottom of the pick-up cowl/cover. No biggie I thought (no oil will come out), until we hit some heavy weather & I was breaking down intermittently till I put some race tape over the hole as a temp to home solution (after everyone was collecting my crap down plastic bag luggage weather covers). Unfortunately it was on the engine side of the cover, so it is JB'd now.
I would add one more thing...
If the fuel cap doesn't seal, then water into the tank and then into the carbs. Water is heavier than gas and will be the first thing sucked into the carbs when it was cranked.
This can result in the poor running issue you are now having.
Randy - RPM
Quote from: racerrad8 on February 23, 2019, 07:44:13 PM
I would add one more thing...
If the fuel cap doesn't seal, then water into the tank and then into the carbs. Water is heavier than gas and will be the first thing sucked into the carbs when it was cranked.
This can result in the poor running issue you are now having.
Randy - RPM
That could very well be. How would I tell? and just drain the tank, and refill?
Just pour out a sample of fuel from the petcock (or even better one of the carb bowls) into a clear container. If you have water in your fuel you will see it sitting in the bottom.
Quote from: T Legg on February 23, 2019, 09:10:21 AM
I have no idea why the US bikes use the orange wire for the tach and every other bike uses the grey wire .
It's probably because it's better colour than grey! and you can! :lol:
Alright, tearing into it yesterday, no water was found anywhere. The coils were dry, and didn't look cracked, the short is gone, I didn't see any water in the side cover, and a sample from both the petcock, and the float bowls were clean. Bike seems to be running just fine now, so the end result is...I have no clue.
Quote from: ryanschoebel on February 25, 2019, 09:46:23 AM
Alright, tearing into it yesterday, no water was found anywhere. The coils were dry, and didn't look cracked, the short is gone, I didn't see any water in the side cover, and a sample from both the petcock, and the float bowls were clean. Bike seems to be running just fine now, so the end result is...I have no clue.
Similar on my side. It sat once in heavy rain and didn't start afterwards. That was long time ago and since then I have ridden it in some heavy rain without a single cough. BUT, still if I wash it with too much water while stationary, it won't fire right up. Has me clueless.