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Bike cranks, but won't fire up?

2K views 9 replies 6 participants last post by  Steve42790 
#1 ·
Hey all, I'm new here and joined because I'm having a weird issue I can't figure out.

Long story short...I went out riding, filled up my tank and rode for the day with no issue at all. Got home and parked the bike. The very next day, maybe 12 hours later, I went out to ride and the bike wouldn't start. It literally just sat there over night. It appears to be fueling, but I'm not sure. It cranks over strong, but just won't fire. If i twist the throttle a bit while trying to start it, it chugs to life and will run as long as I'm holding the throttle, but if I let go and let it idle, it just dies out. The fuel pump primes and sounds strong, all fuses are good. I swapped out the fuel thinking it was bad, i kept trying to run it to get the old fuel out of the lines, and after a few start ups, while holding the throttle open to get it started, it seemed to even out and idle fine. i turned it off and back on again like 5 times and it started up and idled fine. So i concluded i just had bad fuel. I shut it off and the next day I came out to ride it. I started it and it idled normal, went for a test ride and it ran extremely BAD. it broke up/misfired, wouldn't really go past like 4-5k rpm and hesitated and just ran like complete crap. I brought it back and parked it, and after all those successful start ups, I'm right back where I was. cranks strong, but won't start unless i give it alot of throttle.

I tried disconnecting my PC3 and run the factory tune and same issue. I have not checked my spark plugs yet or replaced them, but how could they cause an issue sitting over night?

Any other ideas? One thing I'm gonna try when it stops raining is bypassing my BAS switch to see if that does anything. I really dont think it's the spark plugs, but besides them, does anyone have any other ideas??
 
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#3 ·
I changed my spark plugs, and still have the same issue. All the coil packs are fine as well. vacuum hose for the MAP sensor is also fine.

I just went out and started it, and it started up fine, but then the idle slowly dropped and dropped until it died.

Also, I don't seem to be getting an error code with the FI light. If i turn the key to on, there is no FI light, but if i flick the kill switch to on (but not starting the bike) it comes on and stays on for like 15 seconds then goes off. doesn't blink
 
#4 ·
Your bike is not going into "limp mode" and it's definitely not a BAS issue either, though that was stated above already.

Have you ridden it or just let it idle on the stand? You might have fouled the spark plugs (even though they are new) from all the starting and idling, might want to babysit around the block to clear it out a bit. I'd also be looking in your tank for any signs of rust or a plugged fuel filter.

There is an idle circuit and based on the year of your bike it could have a wax fast idle circuit in there that might be suspect. Basically that controls your idle speed by coolant temerature which as it heats up melts the was and the idle drops. Those can and do go bad, however is there a chance you moved the idle speed adjuster around in an attempt to get it to start? If your idle speed is set too low and the wax starts to melt your idle will drop too low and it will die. That sounds like your bike.

Couple of ideas anyway, hope it helps.
 
#6 ·
I rode it one time, and at roughly 4k rpm it starting misfiring and breaking up so bad it wouldn't accelerate any more and it sounded bad. I thought of the fuel filter already, but I pulled the cage out of the tank and all I saw a little strainer thing on the bottom, not an actual filter. there is no inline filter, so idk where it is, if there is one. somewhere hidden in the cage maybe?

I did adjust the idle, I put it all the way UP, to help get it started, so the idle is around 2k rpm. and then the idle adjuster got stuck as well, it won't turn at all. I cant get it unstuck. but the bike has started up a bunch of times and seemed to idle fine until I give it a rev, then it dies, and if I rev too high it sputters and misfires. and then sometimes it doesn't wanna start at all and i need to give it throttle.

almost positive its not the idle circuit. the bike is always cold when i try to start it or work on it. its never running enough to even get very hot.

the symptoms clearly seem to show (IMO) that it's a fueling issue, or a spark issue. I pulled the plugs today, to go ahead and test all the coils for spark. i plugged each one in and i heard them clicking/zapping but didnt see a spark, but I didnt ground it, so thats why I guess. I also got shocked myself LOL.

Going back to the fuel filter, that is my greatest suspicion, but like I said, i don't know where it is.

I also read a dying/low battery can cause a variety of random issues as well. mine has died multiple times and I've trickle charged it multiple times. and while it cranks strong, maybe it just doesn't have enough juice to power certain things properly? any insight into that?

Thanks for the help guys. I'm pretty mechanically inclined, i haven't really ever ran into an issue like this where im so stumped.
 
#5 ·
^^^^^^ Good advice right here.
 
#8 ·
hey all, I still haven't solved my issue and figured I would throw an update out and bump this. Bike is having the same symptoms. I swapped out the fuel cage thinking it was maybe a clogged or failing fpr or something. No dice. I put in a new ect sensor as well which did nothing. Bike would start for awhile, and idle like crap but it started up every time. Now back to square one where it doesn't even wanna start.

I'm going to do a compression test and also think possibly the MAP sensor is faulty, although its not throwing any codes. The MIL doesn't blink.

Anyone else have any ideas? Can someone give me a little more info on limp mode?
 
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