Ignition issue?

Discussion in 'FXR Models' started by vtfxr, Apr 13, 2009.

  1. vtfxr

    vtfxr Member

    so now that I got the starter issue sorted out a new problem has surface, when cold the bike (88 fxr) will start great but when it warms up it starts to run like (EDITED), missing bad and when I ride it it bogs then catches then bogs right out again. I had a harley tech who is a friend check and adjust my push rods and he seems to think my ignition module has (EDITED) out (crane single fire module in cone, w/ single fire coil and wires) he says these are known to fail when in the cone due to heat. My plugs are new but they look pretty bad if I let it run like this long, the front is all black and the rear looks like it is running hot. I swapped out another set of harley plugs and same thing. I was messing around with the wires leading from the module to the coil(I think) and with it idling like (EDITED) by wiggling the wire bundle I got it to smooth out a couple of times but when I undid the wire ties and tried to isolate out a bad wire I could not duplicate it. I was about to order a dyna single fire 2000i module which I've been told is better suited for the heat in the cone when my friend the harley tech told me it could also be my charging sys causing this since I have a draw when the bike sits. I tested my charging voltage at the battery at idle and got a solid 12.67volts normal?? Needless to say I am a little overhwelmed right now and could use some advice. I don't really have the money to be throwing $200 darts at this time.

    Please read this... (triple header)
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  2. 3wVo

    3wVo Banned

    I do not think it is your charging system being 12.67v is stout. That should be sitting there without running. So if she is charging, that battery is holding a good charge and for sure, the charging system is cooking that battery in perfect order. That eliminates any low voltage to the ignition system.

    I think it is more a fuel delivery problem like check the vacuum unit off the intake manifold. Plug that off at the carb, start it and see if the unit will clean that up being you do not want to throw money at it like you said. But more check if the vacuum is pulling some advance so you do not soot up the cylinders with a morning choke or say I have no clue but to see if we have an ignition situation or a fuel problem.

    I do not know if we can duplicate your deal. It might be as simple as a bad ground or a ground of the ignition to be separate from what you are doing with the starter and that wiring deal. So, it seems if you messed with some wire and it ran better? Could it be a ground and not the vacuum relay to the advancer and it is a bad ground?

    How about the carb float being off where it is bleeding over the jet holes, filling the cylinder a little too much rather that the correct level? I want to know that compression number and not some rod length opening when the valve cannot seal when it is closed to a piston ring and what is the history of that bike before the starter motor?

    I would follow book procedure with a hair dryer or a bottle of cold "dust off" kind of computer chill in a can. So now you have a heat or cold problem to duplicate a bad ignition and not again, spend money is buy another one, install it on the same ground and say, "That was not it was a waste of money is throw parts at it I did."

    1. I place compression at the top of the list and will drill it in your head is just about every post if I come across a no start, that is the first thing I think of and so should you or chase your tail with a low power, no or little compression to make any pressure to push the piston down but run half on gas, half on crank momentum is hope the other one fires next to keep it running. Or neglect this first basic step or pay the cash ear at the counter you did not hear the very first step to any engine diagnostics.
    2. Poor Ground is my first guess at the ignition if you made it run better.
    3. The vacuum is to make sure your intake is closed and no air is being sucked in 'After the Air Cleaner" where dirt or a lean condition would cause the vacuum unit feed a rich set.
  3. glider

    glider Veteran Member


    It seems like you got that language program straightened out somewhat from your first post .:s

    Not one misspelled word in the post.:D
  4. Joyflyin

    Joyflyin Experienced Member Staff Member Moderator

    I like a quick learner. :s
  5. vtfxr

    vtfxr Member

    Thanks for the feedback 3wVo,
    I would have responded back sooner but I got a 5 day vacation from this forum for my last post... I'm going to try your suggestions on Sat and a few other ideas I have and I'll let you know how it turns out. From what I've been able to gather the wire I was wiggling which got the idle to smooth out a couple of times is the ignition module to VOES wire, I'm also going to check the vacuum hose from carb to VOES for leaks, I'm hoping it turns out to be a wiring or vacuum issue as I can't really afford a new module right now.
  6. jel123

    jel123 Active Member

    I had a crane in my bike and it would cut out when warm but if i reached down and moved the wires going into the cone it would return to normal i had a buddy same problem the new ones dodnt have that problem but i bought a ultima programable one from jereh for a 110.00 bucks and havn,t had a problem since,jel
  7. Apyle

    Apyle Junior Member

    My 87 fxrs did the same thing, It turned out it was the ignition module. It finally full on died allowing me to diagnose the problem, before it was just intermittent. When I got the module it was expensive and it had been "updated", The original was hard wired and the replacement had a plug in it. But wonder of wonders the wiring harness for the update had been discontinued! Luckily I'm pretty good with a soldering gun.
  8. vtfxr

    vtfxr Member

    Good News!!!! Well I had determined that I was going to rule out everything possible before firing a module at this thing, so I went back to basics and remembered what an old mentor of mine always tried to beat into my head "visual inspection, visual inspection and then another visual inspection!!!" so I checked evry wire and when I removed my coil this time the ground wire to the frt cylinder fell apart. Quick wiring repair and what do ya know it fired right up and runs like a champ. In the process of checking everything out that has been suggested to me I found one of my intake gaskets cracked and some chaffed wires and hoses that I need to reposition but that is all minor. So thank you very much to everyone who has offered help, as always it is much appreciated.