Engine miss

[SPORT]

Specs:

2005 FJR ABS

Miles: 30,000

Mods:

• Just removed PC-III (it caused TPS to fail several times)
• Barbarian Mod~ +7
• Air box returned to stock

Scenario:

As a note, the roughness does NOT occur during idle and is not felt during acceleration, but most evident while at cruise operation of any speed, but mostly during slower cruising speeds of 5-30MPH. However, the roughness can also be felt during deceleration, but no after-fire is heard. This has been going on for at least a year now, yet was mostly masked by the PC-III. Now that the PC-III is removed, the problem has increased. During engine operation in the garage and on the center stand, I'll lock the throttle at say, 4,000RPM, the engine will intermittently drop down to roughly 3,500RPM, bounce around for 5-10 seconds, then jump back up to 4,000RPM. It repeats this intermittently, but very frequently (3-4 times in a minute). There for a while it seemed to happen while I was trying to move wires and lines around under the tank, but could not isolate it, and the roughness continued even after I stopped moving the wires and lines.

The bike is kept in the garage EVERY night and is only out while riding or camping, and do NOT rely on any one gas station for fuel, so I don't think there is water in the tank; however, no official test for water in the tank has been performed.

Corrective measures done thus far:

• Replaced Spark Plugs with new OEM
• Snipped ends of spark plug wires due to possible corrosion (none was noted)
• Added electrical conductor grease to protect Main electrical plug under tank (no corrosion noted)
• Sync'd carbs both the official and un-official method. All fall well within limits
• TPS has been replaced...twice
• TPS was diagnosed to be working properly and within limits

My next move is to confirm there is NO water in the tank. Then it would be to clean the injectors, and maybe return the CO's back to stock settings. beyond that, I'm unsure what to do.

Any advice and/or suggestions are greatly appreciated!

 

[03HiYoSilver]

Have you run some Fuel Treatment like SeaFoam yet?

https://www.seafoamsales.com/gasoline-engine-faqs.html

If not, run a tank on this and see if this clears things up.

You have done about everything else.

 

[Donal]

I would suggest 'experimenting' with your CO settings. I see they are currently set at +7. I would try increasing them in stages to something like +20 and observe the bikes performance after each change. I have an '09 and mine was kind of rough at lowish RPMs, works much better at +15 across the board.

Don

 

[SPORT]

I would suggest 'experimenting' with your CO settings. I see they are currently set at +7. I would try increasing them in stages to something like +20 and observe the bikes performance after each change. I have an '09 and mine was kind of rough at lowish RPMs, works much better at +15 across the board.

Don

I have done quite a bit of experimenting with CO settings. None of which really affect any change. I've also gone through numerous tanks of gas and still have the same problem. I'm beginning to think that it's electrical and perhaps even in the ECU???

I again fiddled with it. Scenario is as follows:

Warm up on center stand, Throttle lock set at 3,500RPM. RPM will hold steady for approx 45sec. then dip down to 2,500RPM for another 45sec. It will then slowly climb up to 4,200RPM for yet another 45sec, then back down to 2,500RPM. This cycle continues repeatedly. There is NO after or back fire and the engine runs relatively smooth. It just looses power. I will do a compression check this week to confirm it's not mechanical.

Any further thoughts?

 

[ionbeam]

...Warm up on center stand, Throttle lock set at 3,500RPM. RPM will hold steady for approx 45sec. then dip down to 2,500RPM for another 45sec. It will then slowly climb up to 4,200RPM for yet another 45sec, then back down to 2,500RPM. This cycle continues repeatedly....

Any further thoughts?

I believe this is actually normal for a FJR on the center stand. At least for a Gen I. Anyone want to try this and see if they can duplicate these results? (I know my FJR does this.)

 

[joebiodiesel]

If you feel a miss on decel, then your next move is a compression test, then a leakdown test. On decel the injectors aren't firing, so that eliminates both spark and fuel. Time to check the mechanical stuff.

Joe

 

[SPORT]

If you feel a miss on decel, then your next move is a compression test, then a leakdown test. On decel the injectors aren't firing, so that eliminates both spark and fuel. Time to check the mechanical stuff.

Joe

Joe,

Good point.

I'm garaged for a while, but from what I remember, The miss does NOT occur during deceleration. It ONLY occurs while at a steady cruise.

Ionbeam,

I'm familiar with needing to +7 the CO settings to smooth out the 'miss' while at cruise, but it seems worse now that it has 25,000+ miles on her.

 

[joebiodiesel]

However, the roughness can also be felt during deceleration, but no after-fire is heard.

I understand. Maybe the misfire and the roughness are not related. For anything that happens on decel, you can forget about it being related to spark or fuel as there is no combustion during engine braking. You'll be looking for strictly mechanical driveline stuff. Causes can range from uneven compression to a wheel binding, or even a bent shaft in the transmission. None of these things are likely to be mistaken for a misfire though.

Just for giggles, for the problem at cruise, maybe try disconnecting the battery for a few minutes (to clear the fuel trims from the computer), and disconnect the O2 sensor and go for a ride. My thinking is that the O2 may be biased and leaning out your mixture a bit. It's just a guess, but it's free to try.

 

[SPORT]

Just for giggles, for the problem at cruise, maybe try disconnecting the battery for a few minutes (to clear the fuel trims from the computer), and disconnect the O2 sensor and go for a ride. My thinking is that the O2 may be biased and leaning out your mixture a bit. It's just a guess, but it's free to try.

Hmm. Haven't considered that.

I'll give it a shot when I get the time...

Thanks

 

[Fred W]

If you are as sensitive as I am, I believe that whet you are describing is what I call the "lean surging" issue of the stock FI mapping. If I don't run a PCIII on my bike I get exactly what you are talking about. It feels like the speed is "hunting", or varying up and down whenever the throttle is held constant. It is worst at lower loads, low throttle positions, and lower rpms. Adding numbers to the CO setting via barbarian jumper mod did not eliminate the surging on mine. Only the PCIII did the job.

I don't see how a PCIII was causing your TPSes to fail. You might want to get another one.

 

[SPORT]

If you are as sensitive as I am, I believe that whet you are describing is what I call the "lean surging" issue of the stock FI mapping. If I don't run a PCIII on my bike I get exactly what you are talking about. It feels like the speed is "hunting", or varying up and down whenever the throttle is held constant. It is worst at lower loads, low throttle positions, and lower rpms. Adding numbers to the CO setting via barbarian jumper mod did not eliminate the surging on mine. Only the PCIII did the job.

I don't see how a PCIII was causing your TPSes to fail. You might want to get another one.

I agree with your diagnoses, but it seems a bit worse from when i first bought it. The problem is that the PCIII has been on for most of my owning the bike, so I don't recall specifics.

Now that i have my son's Jeep running after replacing the carb, I see a similarity. Namely that it was vacuum leaks that caused the Jeep to run rough at cruise (it accelerated fine).

As such, I'm thinking I have an air/fuel mixture problem that is causing my roughness. Any thoughts to what may cause that?

I have ran a can of Sea Foam through the tank and it is still running rough...like a vacuum leak.

As a note: It was a Yamaha rep (not the dealer) that recommended I remove the PCIII as he has seen it cause problems on other model Yamaha's. Ironically, I have not had ANY error codes since removing it; which suggests the PCIII did adversely effect the TPS.

 

[worldbound4now]

If you are as sensitive as I am, I believe that whet you are describing is what I call the "lean surging" issue of the stock FI mapping. If I don't run a PCIII on my bike I get exactly what you are talking about. It feels like the speed is "hunting", or varying up and down whenever the throttle is held constant. It is worst at lower loads, low throttle positions, and lower rpms. Adding numbers to the CO setting via barbarian jumper mod did not eliminate the surging on mine. Only the PCIII did the job.

I don't see how a PCIII was causing your TPSes to fail. You might want to get another one.

I agree with your diagnoses, but it seems a bit worse from when i first bought it. The problem is that the PCIII has been on for most of my owning the bike, so I don't recall specifics.

With your throttle body synch tool connected, try to lock the throttle again at 3500RPM or 4K RPM and see if it still persists. May be a leak in one of your TBS nipple port caps. I had one that was cracked pretty bad. I could get my TBS to synch up really well but the bike ran oddly after buttoning things up. I wish I could remember the details to the odd problem, but it may be worth a shot. Replaced the cap and no problems since.

 

[SPORT]

With your throttle body synch tool connected, try to lock the throttle again at 3500RPM or 4K RPM and see if it still persists. May be a leak in one of your TBS nipple port caps. I had one that was cracked pretty bad. I could get my TBS to synch up really well but the bike ran oddly after buttoning things up. I wish I could remember the details to the odd problem, but it may be worth a shot. Replaced the cap and no problems since.

Ooooh, great thought!

That's something I haven't considered. I'll try and look into this over the weekend.

Thanks

 

[TownsendsFJR1300]

...Warm up on center stand, Throttle lock set at 3,500RPM. RPM will hold steady for approx 45sec. then dip down to 2,500RPM for another 45sec. It will then slowly climb up to 4,200RPM for yet another 45sec, then back down to 2,500RPM. This cycle continues repeatedly....

Any further thoughts?

I believe this is actually normal for a FJR on the center stand. At least for a Gen I. Anyone want to try this and see if they can duplicate these results? (I know my FJR does this.)

My 04 with 8300 miles was doing the surge thing not bad (maybe 200 RPM) at about 4K in neutral. Runs great, no surge when underway, backfire, etc. NO aftermarket PC, no mods to the co settings. I did sync it sometime ago but today, the surge (in neutral was real bad, 6-700 RPM's, very unusual-never did this). Always garaged, full tank, usually doesn't see rain, had the TPS changed out years ago...

Tomorrow, I guess I'll be checking battery terminals, TPS, re-set computer (disconnect battery for 10 minutes) and if need be, partially drain the tank and check the thottle body caps and put the sync on it. Probably re-check the plug above the engine known to corrode, mine did, cleaned it, di-lectric grease) been fine for 4-5 years...

I'll post if I figure it out... fun day....................

 

[SkooterG]

...Warm up on center stand, Throttle lock set at 3,500RPM. RPM will hold steady for approx 45sec. then dip down to 2,500RPM for another 45sec. It will then slowly climb up to 4,200RPM for yet another 45sec, then back down to 2,500RPM. This cycle continues repeatedly....

Any further thoughts?

I believe this is actually normal for a FJR on the center stand. At least for a Gen I. Anyone want to try this and see if they can duplicate these results? (I know my FJR does this.)

My 04 with 8300 miles was doing the surge thing not bad (maybe 200 RPM) at about 4K in neutral. Runs great, no surge when underway, backfire, etc. NO aftermarket PC, no mods to the co settings. I did sync it sometime ago but today, the surge (in neutral was real bad, 6-700 RPM's, very unusual-never did this). Always garaged, full tank, usually doesn't see rain, had the TPS changed out years ago...

Tomorrow, I guess I'll be checking battery terminals, TPS, re-set computer (disconnect battery for 10 minutes) and if need be, partially drain the tank and check the thottle body caps and put the sync on it. Probably re-check the plug above the engine known to corrode, mine did, cleaned it, di-lectric grease) been fine for 4-5 years...

I'll post if I figure it out... fun day....................

Do you notice any issues while riding? I mean, is there really any problem if you don't? If no issues when riding, who cares what it does in neutral? I would NEVER even try this so-called 'test'. Don't go try fixing what ain't broke.

 

[TownsendsFJR1300]

...Warm up on center stand, Throttle lock set at 3,500RPM. RPM will hold steady for approx 45sec. then dip down to 2,500RPM for another 45sec. It will then slowly climb up to 4,200RPM for yet another 45sec, then back down to 2,500RPM. This cycle continues repeatedly....

Any further thoughts?

I believe this is actually normal for a FJR on the center stand. At least for a Gen I. Anyone want to try this and see if they can duplicate these results? (I know my FJR does this.)

My 04 with 8300 miles was doing the surge thing not bad (maybe 200 RPM) at about 4K in neutral. Runs great, no surge when underway, backfire, etc. NO aftermarket PC, no mods to the co settings. I did sync it sometime ago but today, the surge (in neutral was real bad, 6-700 RPM's, very unusual-never did this). Always garaged, full tank, usually doesn't see rain, had the TPS changed out years ago...

Tomorrow, I guess I'll be checking battery terminals, TPS, re-set computer (disconnect battery for 10 minutes) and if need be, partially drain the tank and check the thottle body caps and put the sync on it. Probably re-check the plug above the engine known to corrode, mine did, cleaned it, di-lectric grease) been fine for 4-5 years...

I'll post if I figure it out... fun day....................

Do you notice any issues while riding? I mean, is there really any problem if you don't? If no issues when riding, who cares what it does in neutral? I would NEVER even try this so-called 'test'. Don't go try fixing what ain't broke.

Thanks SkooterG. No other than that it runs great... Just checked the TPS for S & G's, its fine. Being its been awhile since I synced the TB's, I'm going to check them in the am.

Question, I didn't pay much attention to the 25 cm called for in the manual for base #3 TB but did sync the others well within 5mm of #3. Should #3 be higher or lower than 25CM, will adjusting THAT SCREW (not the butterflys) in or out bring up (or down) the vacuum pressure?

I ask as I found a thread elsewhere, that the op, once he had the # vacuum pressure to spec and syned the rest to it made a big difference...

 

[03HiYoSilver]

...

Question, I didn't pay much attention to the 25 cm called for in the manual for base #3 TB but did sync the others well within 5mm of #3...

Don't worry about the CM numbers are...just balance them to #3 and you should be good to go.

 

[TownsendsFJR1300]

...

Question, I didn't pay much attention to the 25 cm called for in the manual for base #3 TB but did sync the others well within 5mm of #3...

Don't worry about the CM numbers are...just balance them to #3 and you should be good to go.

Thank you....

 

[3dogs]

I've read through all the posts and I can't tell exactly what's wrong with your bike? From what I read I don’t think anything is wrong (you must have lots of free time on your hands). Holding the throttle steady in neutral as a diagnostic tool is useless as there is virtually no load on the engine and engine RPM will never be steady for very long on any bike.

I you want some meaningful help/advice please be more specific as to what the symptoms are regarding the engine running rough. For example:

Describe running rough – hesitation or stumble on acceleration, misfire, what?

Does it cold/hot/either?

What gear are you in when it happens? How fast are you going MPH? (you mentioned 5 to 30mph, how does it run at 60 or 70 mph?)

How far open is the throttle when you experience the problem?

Are you accelerating? Holding a steady cruise?

When did this problem start? Instantaneously? Started small but got worse?

Did you (or anyone) do something to the engine/make an adjustment to the fuel system (TB sync?)

****************************

Since others are taking a wild-assed guess as to what’s wrong here is mine. The engine is running normally. To “fix” your issue do the following:

Put the CO adjustment back to where it was from the factory.

Reinstall the PCIII with an appropriate fuel map. (make sure it’s grounded directly to the battery -- the PCIII not the map)

Sync the throttle bodies – use the unauthorized method HERE (fifth post down).