Hi guys, Im new to the site but have riden an FJ1100 for years, there has been some mods to it which I will post later, my problem that I need help with at the moment is as follows. I thought that I filled up with some bad fuel as she started to miss or hunt particulary between 4 and 6000 RPM, took her to my mechanic and had a good service done but still hunting, we have checked spark, carbs all is good the only thing we can come up with is that it is the TCI unit vacumn that is playing up, has anyone else had this problem or any sugestions will be welcome. Speak soon.
Not enough information to really help there.
New problem? Mods are what again? Problem under what throttle conditions? What's a "good service" involve?
Guessing: vacuum leak, check the intake boots for cracks. With the bike idling, spray WD40 in and around the boots, if the engine surges, you have a leak.
But without more, this is just a guess.
Dan
Mice in the airbox.
Quote from: andyb on February 27, 2011, 04:10:18 AM
Not enough information to really help there.
New problem? Mods are what again? Problem under what throttle conditions? What's a "good service" involve?
Yes it is a new problem never happened in the last 10 years. Mods are modifications, there was nothing done to the engine itself, just rims (17inch) and a few other cosmetic changers for looks(willpost picture). The problem occurs under normal throttle conditions going through the gears changing up at about 5 to 6000 rpm no matter what gear you are in this hunting happens between 4 and 6 000 rpm. A good service is change oil, oil filter, air filter,clean and calabrate carbs, check and adjust chain and a general check on lights, electrics, etc. hope this is more help.
Is it a wide open throttle problem? or just half throttle , normal ride going thru the gears thing.....meaning hard acceleration or cruising?
Quote from: Mark Olson on February 28, 2011, 11:21:03 AM
Is it a wide open throttle problem? or just half throttle , normal ride going thru the gears thing.....meaning hard acceleration or cruising?
Normal going thru the gears not hard acceleration just taking the revs up( cruising) and the hunting starts at 4000
Just for shit & giggles, try adding choke when it happens.
That should tell you if it is jetting? and which way to go.
As long as your tune up is good, it should be a good place to start.
Bob
pull the carbs and clean them , check diaphragms for pin holes. you have a transition problem between the circuits in the carbs.
Quote from: Mark Olson on March 01, 2011, 01:25:09 PM
pull the carbs and clean them , check diaphragms for pin holes. you have a transition problem between the circuits in the carbs.
Thanks, Will check for pin holes, my mechanic recons that it may be a TCI problem to do with the vacumn pipe, have you heard of this or is it a known fault of the FJs, I think it is something simple well I hope it is as parts in South Africa are hell of an expensive, it will be cheaper to fly them in from US, The local dealer quoted me R 6500, 00 ( about $1000)for a CDI unit.
I doubt it's that, but I have 3 or 4 so don't buy a new one.
Bob W
Just a thought have you checked the side stand switch mine did exactly that! did you use the side stand when you filled up with fuel before it started? just a thought as its a common fault.
Quote from: bluedirtydigit on March 04, 2011, 02:50:26 AM
Just a thought have you checked the side stand switch mine did exactly that! did you use the side stand when you filled up with fuel before it started? just a thought as its a common fault.
Really? I thought the side stand switch was a binary fault. The bike starts or not. You actually had hunting symptoms from a side stand switch problem??!!??
Dan
Any mechanical switch that controls the ignition can become a very strange misfire if it resonates and goes bad at a certain frequency.
<edited to be nicer to original poster>
Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.
Keep the rubber side down
Quote from: fugly on March 09, 2011, 03:41:42 PM
Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.
Keep the rubber side down
Uh, how do you turn the lights off without dissconnecting them? Do you mean high-beams?
Just curious.
Dan
Relays are good. Do both the light relay and coil relay...getting full voltage works wonders for lumens and spark.
However, I'm unconvinced that low voltage from the oem wiring harness, is the root cause of your symptoms.
Something else is going on...
Quote from: fugly on March 09, 2011, 03:41:42 PM
Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.
Keep the rubber side down
Pull the fuse.
Quote from: Dan Filetti on March 09, 2011, 08:17:58 PM
Quote from: fugly on March 09, 2011, 03:41:42 PM
Thanks for all the help, looks like it was a voltage thing after all, when the lights are on she hunts way more than when the lights are turned off, read about putting the relay into the curcuit so will be doing it this weekend and seeing if that solves it, will keep you posted, Once again thanks for all the input.
Keep the rubber side down
Uh, how do you turn the lights off without dissconnecting them? Do you mean high-beams?
Just curious.
Dan
Is this what you did, pull the fuse?
Like Pat, I'm dubious that this is the root cause of your issue.
Dan
Quote from: Dan Filetti on March 10, 2011, 07:37:19 PM
Is this what you did, pull the fuse?
Like Pat, I'm dubious that this is the root cause of your issue.
Dan
Unless the light circuit has a short in it...
Randy T
Indy
How would this be the case Randy? The light circuit is a different circuit than the coil/ignition circuit...
Quote from: rktmanfj on March 10, 2011, 09:01:07 PM
Unless the light circuit has a short in it...
Randy T
Indy
Quote from: Pat Conlon on March 10, 2011, 09:07:37 PM
How would this be the case Randy? The light circuit is a different circuit than the coil/ignition circuit...
Quote from: rktmanfj on March 10, 2011, 09:01:07 PM
Unless the light circuit has a short in it...
Randy T
Indy
Damned top posters... :biggrin:
If he has a short in the light circuit (not necessarily to ground), it could cause all sorts of weirdness, and not pull enough current to smoke the fuse, especially if a DPO put the wrong fuse in it.
If it truly does change when the light circuit is hot, I'd at least consider isolating the lights and trace them.
Randy T
Indy
Just an offhanded, idle question. How old's the battery, and what odds on the r/r feeding it a pinch aggressively? It's happened once or twice before on the FJ, I understand....
Quote from: andyb on March 11, 2011, 08:01:24 AM
Just an offhanded, idle question. How old's the battery, and what odds on the r/r feeding it a pinch aggressively? It's happened once or twice before on the FJ, I understand....
I guess anything is possible, but I don't see where overvoltage to the coils is going to do anything but throw a fatter spark at the other end, and if the battery starts the bike okay, don't know what the problem could be there.
But if the light circuit really is causing a problem when it's energized, then tracing that would be my first step.
Randy T
Indy
I'm thinking more to the extent of torching a "reasonably good" battery and giving problems if the overvoltage situation is transient, i.e., when the r/r or other portions of the generation circuit are too hot. If nothing else, on nearly any mysterious electrically related fault, a new, known good battery is a reasonably easy troubleshooting step, and a good foundation to build from for further troubleshooting.
I'll preface this by saying I'm not an expert, and am willing to be educated. However, I will say that the reasoning for my doubt that "hunting between 4-6K RPM" is a spark issues, is rooted in the firm belief that a spark plug either sparks and lights the gas, or it does not.
This idea that a 'fatter spark' being important has always annoyed me. For the same reason, I never buy expensive, fancy, multi-tipped, titanium spark plugs I also think that an awful lot of time and energy goes into this, yet it may only be important for the folks that are dealing in that last .05% of the performance tuning -not even certain there.
So, the spark is either there or it's not, the cylinder is either firing or it's not, and, it seems to me, the plugs should show this. Read the plugs: is there any indication that any/ all of them are rich/ carbonized? If so, you may have an issue where you need to look at whether/ if you have spark issues. Note: these could just as easily (more likely in my mind given the symptoms) be a carburetion issue.
I know a weak battery can cause wonky behavior, and that may be worth doing prophylactically if it's older, but "hunting between 4-6K RPM" just 'feels' like a fueling issue. All that being said, my opinion, and $1.75 will buy you a cup of coffee at Starbucks.
I'm still curious whether you actually pulled the headlight fuse to test this. Seems an odd/ random test if so. What made you consider this?
Dan
Quote from: andyb on March 11, 2011, 09:58:21 AM
I'm thinking more to the extent of torching a "reasonably good" battery and giving problems if the overvoltage situation is transient, i.e., when the r/r or other portions of the generation circuit are too hot. If nothing else, on nearly any mysterious electrically related fault, a new, known good battery is a reasonably easy troubleshooting step, and a good foundation to build from for further troubleshooting.
True, but IME, if the battery voltages (with and without load) are nominal and constant, it already
is a known quantity, IMO.
Overvoltage has not been mentioned here as a symptom here, BTW, though it
is an FJ, I guess it can be assumed.
Randy T
Indy
Hi, Guys
Just a reply to some of the comments made regarding my questions, Firtsly it is easy to turn the light off I use the light switch on the right hand handlebar controls it has three settings off/ park and on. If I am riding and turn the lights off she runs a lot smoother as soon as I turn th elight switch to on she starts to hunt. We have checked for bad connection or earthing did not see anything. we have tested all possible voltage points battery etc and all is OK, she starts fine even if you leave her standing for a week or so, The battery is only a year old pushes 13,6 Volt, we are doing the relay thing over this weekend and will take her for a ride and give feed back. Thanks for all the interesting posts.