Suddenly Backfires on Deceleration (constantly)
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TownsendsFJR1300
Well-known member
:yahoo: :yahoo: :yahoo:
Looks Like Silver wins the prize
onnector A is corroded:
I'll start cleaning them tonight after work ....
Thats easily 3 times worse than mine when mine started acting up..... I'm surprised it still ran... Make sure you put lots of dilectric grease in there, no more corrosion after that....
Other than "scraping" with a small pick, any and all other suggestions on how to get all that crud out of my connectors would be greatly appreciated !
RadioHowie
I Miss Beemerdons!
Can't find the injectors unless you lift the tank. Thought that was fairly obvious. :finger:
RadioHowie
I Miss Beemerdons!
Get a can of spray contact cleaner from Rat Shack, then plug-unplug-plug-unplug and repeat about 2000 times, with repeat sprayings until the goop is gone.
TownsendsFJR1300
Well-known member
I know where the injectors are, having done several syncs myself on it as well as a throttle spring un-wind. I guess you don't know either how to ACTUALLY check an injector (IE is it done on the bike running, just removing and sending out to a shop, etc).
TownsendsFJR1300
Well-known member
As posted above pick at it, if you have an air compressor and WD40 should help loosen it. I believe I used an old tooth brush to help loosen the crud. It got into most of the nooks and crannies....
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RadioHowie
I Miss Beemerdons!
That would be an incorrect guess.
To check the injectors for operation, you would have to pull the tank and remove each injector from the fuel rail, leaving the injectors plugged in to the wiring harness.
Then, after entering the DIAG mode through the instrument cluster, you would first put the kill switch into the OFF mode, then cycle the DIAG readout up to #36. Turn the kill switch back to the normal RUN position and fuel will come squirting out of the #1 injector. The injector will pulse and spray fuel 5 times per second until you switch the kill switch back off.
Cycle up to #37 and repeat for injector #2, #38 for injector #3 and #39 for injector #4.
Visually compare the fuel flow from each injector as you cycle up and down the DIAG codes. A clogged injector will be display an obviously different fuel flow from an un-clogged injector. Unclogged will give you a nice big spray of fuel. A clogged injector will either not flow any fuel, or just let fuel dribble out the end of the injector.
wfooshee
O, Woe is me!!
Look RH, somebody thought you were being serious!!!! 
How often does that happen??!?!
You have to improve your use of smilies.
(Here it comes . . . . .)
How often does that happen??!?!You have to improve your use of smilies.
(Here it comes . . . . .)
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TownsendsFJR1300
Well-known member
Thank you, thats what I wanted to know... I have a four stroke FI 150 HP Yamaha outboard that may have had FI problems. Short of replacing each(or sending them off for cleaning) I wanted to know.
I take it with the injector(s) disconnected from the fuel rail, there's enough fuel in them to see their performance when activated?
wfooshee
O, Woe is me!!
Yeah, just a bit. Pressure goes away nearly instantly.
TownsendsFJR1300
Well-known member
RadioHowie
I Miss Beemerdons!
(shuffling feet, looking a bit embarassed.....)
I should have been more precise....pull the fuel rail with the fuel injectors still installed from the intake manifolds...then step through the diagnostics as descriibed above.
That way, the injectors still get a supply of fuel that doesn't disappear with the first test. Just be carefull when you put it back on that the O-rings at the end of each injector are still in place.
It sounds like a lot of work just to verify injector action, but in actuality, it' only removing the two mo-fo screws that hold the fuel rail in place, than a little careful fore-and-aft rocking of the rail while pulling away from the motor to pull the injectors out of their seats in the throttle bodies.
Look RH, somebody thought you were being serious!!!!
(Here it comes . . . . .)
Yeah...I screwed the pooch on that one.
Uh-oh....mentioning sex with animals is sure to have Bust join this one! :dribble:
wfooshee
O, Woe is me!!
Glad you came back and 'splained before it was tried the way I said and somebody got mad at me. . . . .
Just to clarify my earlier post. I was joking, too, because I felt a little weird when I posted, and forgot my smiley. Right after fussing at RH for his lack of same!
I'm so ashamed.
(Well, somewhere there might be a universe where that's true. . . . .)
A loose injector will not spray, there's no pressure whatsoever in it if you pull it off the rail. Maybe a residual dribble, but that'll make you think it's bad.
It should go without saying that you don't want open flame, sparks, hotplates, heaters, light fixtures, fans, anything, within 50 feet of a spraying injector, and you don't want to watch it spray more than a fraction of a second, just to see that it does. Spray into a VERY absorbent rag, then dispose of it properly. (Take it out to the street and light it!)
Just to clarify my earlier post. I was joking, too, because I felt a little weird when I posted, and forgot my smiley. Right after fussing at RH for his lack of same!
I'm so ashamed.
(Well, somewhere there might be a universe where that's true. . . . .)
A loose injector will not spray, there's no pressure whatsoever in it if you pull it off the rail. Maybe a residual dribble, but that'll make you think it's bad.
It should go without saying that you don't want open flame, sparks, hotplates, heaters, light fixtures, fans, anything, within 50 feet of a spraying injector, and you don't want to watch it spray more than a fraction of a second, just to see that it does. Spray into a VERY absorbent rag, then dispose of it properly. (Take it out to the street and light it!)
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TownsendsFJR1300
Well-known member
Thanks for the information guys. Thats exactly what I wanted to know...
I have a shop manual coming for the outboard engine, hopefully it addresses how to get into the diagnostic section.
The dealer had replaced the throttle bodies under warranty- (almost $1,000). The fuel rail and injectors are closer to the head of course. It had some off idle, intermediate, hesitation,stalling but is now running 95% better. There's two, two bore throttle bodies so sync'ing isn't difficult (4 cylinder, about 2300 CC).
I have a shop manual coming for the outboard engine, hopefully it addresses how to get into the diagnostic section.
The dealer had replaced the throttle bodies under warranty- (almost $1,000). The fuel rail and injectors are closer to the head of course. It had some off idle, intermediate, hesitation,stalling but is now running 95% better. There's two, two bore throttle bodies so sync'ing isn't difficult (4 cylinder, about 2300 CC).
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Back to the topic at hand ....
Thoroughly cleaned the connectors .... Which didn't fix the problem
Time to pull the right side fairing and check all the coil connections (and re-check all the header bolts)
Still backfiring a lot on decel .... and a clearly noticeable miss at idle on cylinder 3 or 4 ...
(where should I look)
Thoroughly cleaned the connectors ....
Which didn't fix the problem Time to pull the right side fairing and check all the coil connections (and re-check all the header bolts)
Still backfiring a lot on decel .... and a clearly noticeable miss at idle on cylinder 3 or 4 ...
Loose on which end - plug or coil ?
(where should I look)
03HiYoSilver
Well-known member
Loose on which end - plug or coil ?
(where should I look)
Sometimes the Screwed is Wires of the Plug Wire to the Sparkplug boot get loose. You just unscrew them, trim off about 1/4" and ReScrew them back into the Sparkplug boot.
You can check the Coils to make sure the Tangs aren't bent to a Shorted Position.
https://www.fjrforum.com/forum//index.php?s...st&p=714281
(where should I look)
Sometimes the Screwed is Wires of the Plug Wire to the Sparkplug boot get loose. You just unscrew them, trim off about 1/4" and ReScrew them back into the Sparkplug boot.
You can check the Coils to make sure the Tangs aren't bent to a Shorted Position.
https://www.fjrforum.com/forum//index.php?s...st&p=714281
03HiYoSilver
Well-known member
Faster,
Make sure you get to the Main Harness Connector... the one you shown is NOT it. It is located farther up in front of the Triple Tree and is about 3" wide.
https://www.fjrforum.com/forum//index.php?s...mp;#entry268059
Here's Rad's Symptoms and fix results:
https://www.fjrforum.com/forum//index.php?s...st&p=450507
Make sure you get to the Main Harness Connector... the one you shown is NOT it. It is located farther up in front of the Triple Tree and is about 3" wide.
https://www.fjrforum.com/forum//index.php?s...mp;#entry268059
Here's Rad's Symptoms and fix results:
https://www.fjrforum.com/forum//index.php?s...st&p=450507
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Well ...... after far too many days and nights of pulling my hair out trying to find the cause of this ...
... finding and solving the final solution was actually pretty simple ...
To make a long story long:
1) I obviously have far too much trust in modern electronics (I design integrated circuits)
2) I know that all the components which could have possibly caused this problem are functioning correctly
- AIS plugs and ports are secure
- Vacuum plugs on throttle bodies have been replaced with "no cracks" new plugs
- Plug wire connections to plug boots are secure and electrically sound
- Connections to coils are solid and free of any possibility of shorting
- Header connections to engine are solid and free of any leaks
- Connector "A" has had all the corrosion removed, all contacts cleaned, and dielectric grease added
3) The misfire + backfiring was caused by a "hiccup" in the Power Commander III.
- Again, the signs of the problem were extensive backfiring on decel, low power, and an obvious
misfire at idle on cylinders 3 or 4 (easy to find because of Holeshot system's dual 2-1 design)
- When I removed the PC3 the idle smoothed out (no more misfiring on cylinders 3 or 4 at idle).
- got on the phone with Dynojet customer service, told them what my PC3 was doing:
... it only "communicated" with my laptop computer when engine was running ... it would get serial number, give "error code 12", and say "no connection"
(same thing with bike or external battery power)
... Dynojet tech had me download latest version of software (which now allows reset of PC3)
... with the engine idling (misfiring), at the moment I reset PC3 I said to the tech "wow, the idle just smoothed out"
... before resetting, "getting tune" from the PC3, every entry in the map had -- -- -- -- -- -- -- -- -- -- -- --
.. after resetting, all the map entries changed to zeros
... re-installed my tune, and everything is fine
On a side-note, even though it was still misfiring and backfiring at the time because of the PC3 error,
after I cleaned "connector A", there was a noticeable reduction in backfiring and improvement in performance.
... finding and solving the final solution was actually pretty simple ...
To make a long story long:
1) I obviously have far too much trust in modern electronics (I design integrated circuits)
2) I know that all the components which could have possibly caused this problem are functioning correctly
- AIS plugs and ports are secure
- Vacuum plugs on throttle bodies have been replaced with "no cracks" new plugs
- Plug wire connections to plug boots are secure and electrically sound
- Connections to coils are solid and free of any possibility of shorting
- Header connections to engine are solid and free of any leaks
- Connector "A" has had all the corrosion removed, all contacts cleaned, and dielectric grease added
3) The misfire + backfiring was caused by a "hiccup" in the Power Commander III.
- Again, the signs of the problem were extensive backfiring on decel, low power, and an obvious
misfire at idle on cylinders 3 or 4 (easy to find because of Holeshot system's dual 2-1 design)
- When I removed the PC3 the idle smoothed out (no more misfiring on cylinders 3 or 4 at idle).
- got on the phone with Dynojet customer service, told them what my PC3 was doing:
... it only "communicated" with my laptop computer when engine was running ... it would get serial number, give "error code 12", and say "no connection"
(same thing with bike or external battery power)
... Dynojet tech had me download latest version of software (which now allows reset of PC3)
... with the engine idling (misfiring), at the moment I reset PC3 I said to the tech "wow, the idle just smoothed out"
... before resetting, "getting tune" from the PC3, every entry in the map had -- -- -- -- -- -- -- -- -- -- -- --
.. after resetting, all the map entries changed to zeros
... re-installed my tune, and everything is fine
On a side-note, even though it was still misfiring and backfiring at the time because of the PC3 error,
after I cleaned "connector A", there was a noticeable reduction in backfiring and improvement in performance.
RadioHowie
I Miss Beemerdons!
Wow...congrats on finding/solving the problem. Might be a record time in resolving it, too....just 5 days from your 1st post.
May be too quick to deserve a
piccy in your siggy, but good for you.
Now, GO RIDE!!! :yahoo:
(Man, I just LOVE these "I Fixed It!" posts!)
May be too quick to deserve a
Now, GO RIDE!!! :yahoo:
(Man, I just LOVE these "I Fixed It!" posts!)
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