2016-03-31 KrZy8 Running Rough just above idle

[dcarver]

So the thought crossed through the cranium scareabellium how wonderful KrZy8 was running.


JINX!

Yesterday, on commute, heard back firing on de-cel. Hmm.
..and mpg avg going from 44+ (unusually high)
..to 28 mpg (unusually low except if at go-to-jail-speed)
..and back and forth.

So, stopped by Chevron (my top-tier provider of choice), added 8.7 gallons to main and aux tank.
Purchased a bottle of 'Techron' and dumped all into the 6.6 gallon main tank.

Rode home, added SeaFoam, 3/4 bottle to Aux tank.

After just under 200 miles, (and mixing Aux tank SeaFoam with main tank Techron as the gauge dipped), she WAS running a *bit* better.

Main symptom? Transitioning off idle up to 3k rpm.

Idle, stable.

MPG - all over the place.

Firing misorder very evident from left bank, cylinders 1 or 2 as evidenced by placing hand at left exhaust. Can't be missed. Substanital.

Ok then.

Bike home, removed all plugs. All look good.

Removed fuel rail.

Going to replace injectors, 1, 2 with spares I have laying around.
Will replace 1, 2 sparking plugs too.

I care less about what's wrong than just

getting her fixed.

That is why I'm not an engineer... LOL.

Root Cause?
Good question.

My best hypostehsis is this-
My Aux Tank had an aluminum baffle cross-welded in on each quadrant. Only tack welded, which broke.
I attempted to fix by using JBWeld for gas.
Which broke free.

3 - 4 inch sections of JBWeld broke free after years of riding the dirt road back home.

The aluminum baffle plate, no longer secured, rotated to a postion where the JBWeld was rubbing against a section of the interior tank. The JBWeld was visibly reduced by the rubbing; from approx 5mm 'bead' to half that.

And all that JBWeld went somewhere.

I don't have a fuel filter between the aux tank and main tank.. but will have one by end of day tomorrow.

Will test the 2 injectors removed from KrZy8 tomorrow using a DIY homebrew method.

...and also test 2 injectors from the 'old' rail too.

Should be fun!

Later..

 

[Fred W]

Jebus, Carver... you could have your own forum just on what goes wrong, or has been wrong in the past, with that KrZy8.

Sorry, I have no suggestions (this time) for how to get it fixed, or even theories to float (that you don't want to hear) on what might be the root cause, but will get the popcorn ready and look forward to the updates.

 

[RossKean]

If your exhaust header is OEM "normal" and the cats are not plugged on one side, there shouldn't be any difference in exhaust velocity/volume from one side to another as a function of how well 1-2 are working compared to 3-4. The exhaust is 4 into 1 into 2.

Normally, I wouldn't suggest that fuel injector plugging is likely but given the history you described, it may be possible. In addition to having them properly serviced including ultrasonic cleaning, replacing inlet "filters" and evaluating spray pattern. Depending on the cost, you might want to check out used injectors or even a whole used throttle body with injectors for $152 on Ebay

https://www.ebay.com/itm/G-YAMAHA-FJR-1300-AS-2006-OEM-THROTTLE-BODY-CARBURETOR-INJECTORS-BODIES-FUEL-/141702725436?hash=item20fe23ff3c:g:ur0AAOSw-vlVjEtq&vxp=mtr

Check the pickup screen on your fuel pump to make sure it isn't plugged. This wouldn't explain the symptoms but if there's crap in the tank, the problem could come back after getting it "fixed". I might try some Yamaha Ring Free as long as you are still looking at simpler (and cheaper) chemical fixes.

Good luck!

Edit: I once had similar symptoms on my '07 (running very rich, lousy gas mileage and very poor off-idle throttle response). As far as I could determine, the issue was the result of the O2 sensor wire being pinched when the timing chain cover was replaced when servicing the CCT. The FJR will run OK without an O2 sensor but I suspect it doesn't like it if the O2 sensor is giving a wrong reading. O2 sensors can go bad...

Obvious other stuff would be bad plug, bad plug wire/connection, bad coil.

Again, Good Luck!

 

[RaYzerman19]

First off, no more chemicals...... you already got too much in there (maybe). I'd say check the usual things, no vacuum leaks, TB sync passages clean, and if in doubt about the injectors, have them tested and cleaned. Maybe new spark plugs. After that, see what happens......

 

[dcarver]

Here's what she sounds like -
https://vimeo.com/161416885

• Removed fuel rail, tested all 4 injectors
  https://vimeo.com/161416883
• Dumped all gas from tank, clean, dry, no debri. Fresh <straight> gas in
• Swapped ECU with known good
• Replaced all sparking plugs with new
• Replaced air filter with new (old one not bad at all)

No joy.

Did find a wire harness crimped by the airbox lid.. It goes to what I think is a psia sensor monitoring air box pressure.

 

[dcarver]

I did find one kinda-clogged injector.. Thought I had found the root cause. But noonooo....

https://vimeo.com/161519340

 

[dcarver]

Compression is as follows cyl 1=170, 2=190, 3=178, 4=180. Throttle WFO.

2 runs, averaged.

 

[ionbeam]

Compression is as follows cyl 1=170, 2=190, 3=178, 4=180. Throttle WFO.2 runs, averaged.

With a cold engine?

If this is part of your misfire hunt, you probably won't find the misfire in the compression. However, you have now confirmed that there is nothing drastically wrong with the compression.

Would you be open to the suggestion that your aftermarket exhausts may causing an exhaust scavenging issue at that one non-resonant rpm range?

Is your Air Injection System still installed?

 

[PhilJet09]

Your solution is simple - move to a place with a shorter/smoother driveway. The way I see it, it'll fix almost all of your FJR issues.

Does that help? :biggrinsmiley:

 

[dcarver]

Compression is as follows cyl 1=170, 2=190, 3=178, 4=180. Throttle WFO.2 runs, averaged.

With a cold engine?

If this is part of your misfire hunt, you probably won't find the misfire in the compression. However, you have now confirmed that there is nothing drastically wrong with the compression.

Would you be open to the suggestion that your aftermarket exhausts may causing an exhaust scavenging issue at that one non-resonant rpm range?

Is your Air Injection System still installed?

Dr. Ion, the miss is significant and a repeat from last Nov/Dec. It's unhealthy and not normal. Yes, cold engine. Worst case scenario. The last time, we threw ignition coils, fuel injector harness, ECU, O2 sensor at it.

No happiness until a new to me TB assembly e.g. used Ebay, was installed. At first fire, all was good and she has run great for about 8k miles. Now the same symptoms are back.

Your solution is simple - move to a place with a shorter/smoother driveway. The way I see it, it'll fix almost all of your FJR issues.
Does that help?

Well, no, not really, but what the heck!

In the meantime, I gave her a bath tonight. Maybe that will cure all.

No error codes either.

 

[dcarver]

Jebus, Carver... you could have your own forum just on what goes wrong, or has been wrong in the past, with that KrZy8.

Sorry, I have no suggestions (this time) for how to get it fixed, or even theories to float (that you don't want to hear) on what might be the root cause, but will get the popcorn ready and look forward to the updates.

I know... but it has given Naomi a chance at first chair, which is good. I almost have all farkles ready for her for one big build instead of multiple little ones. I kinda like SPORT mode.

If your exhaust header is OEM "normal" and the cats are not plugged on one side, there shouldn't be any difference in exhaust velocity/volume from one side to another as a function of how well 1-2 are working compared to 3-4. The exhaust is 4 into 1 into 2.
Normally, I wouldn't suggest that fuel injector plugging is likely but given the history you described, it may be possible. In addition to having them properly serviced including ultrasonic cleaning, replacing inlet "filters" and evaluating spray pattern. Depending on the cost, you might want to check out used injectors or even a whole used throttle body with injectors for $152 on Ebay

https://www.ebay.com/itm/G-YAMAHA-FJR-1300-AS-2006-OEM-THROTTLE-BODY-CARBURETOR-INJECTORS-BODIES-FUEL-/141702725436?hash=item20fe23ff3c:g:ur0AAOSw-vlVjEtq&vxp=mtr

Check the pickup screen on your fuel pump to make sure it isn't plugged. This wouldn't explain the symptoms but if there's crap in the tank, the problem could come back after getting it "fixed". I might try some Yamaha Ring Free as long as you are still looking at simpler (and cheaper) chemical fixes.

Good luck!

Edit: I once had similar symptoms on my '07 (running very rich, lousy gas mileage and very poor off-idle throttle response). As far as I could determine, the issue was the result of the O2 sensor wire being pinched when the timing chain cover was replaced when servicing the CCT. The FJR will run OK without an O2 sensor but I suspect it doesn't like it if the O2 sensor is giving a wrong reading. O2 sensors can go bad...

Obvious other stuff would be bad plug, bad plug wire/connection, bad coil.

Again, Good Luck!

Exhaust header is OEM. No difference in exhaust volume per side. I posted a video on Vimeo above showing spray pattern.

..yes last time this occurred, a new-to-me- TB assy cured it.. But why me, why yet again? Nothing but top-tier fuel (Chevron normally) with occasional Seafoam dosing, approx every 6 tanks.

I do have a spare O2 sensor, will test more as time allows. Which is getting short for me. I have to go back to nuclear jail.

 

[NTXFJR]

I had very similar symptoms on my Honda V65. Turned out that the ignition coils were breaking down under heat and load. They would fire, but not as well as they should. It ran slightly rougher than it did before hand especially just off idle, fuel economy went to crap, I couldn't keep a set of plugs in it for more than a few hundred miles before they would crud up. On this one, new coils made it good again.

 

[RossKean]

If you still have crap in the fuel system as a result of the auxiliary tank issue, the replaced TB might now be screwed for the same reason - fine particulates floating around. Fuel injectors have a fine mesh (generally replaceable) screen or filter basket at the inlet. Some minor surgery to have a look might be worthwhile. Perhaps a quick dunk of the filters in an ultrasonic tank is worthwhile.

 

[Fred W]

Any difference to the symptom when stone cold vs fully warmed up?

 

[NBB]

Does the misfiring when the engine is cold happen in a similar manor with the stock exhaust? If so, the aftermarket exhaust may be flowing a bit more than stock, and when cold the stock ECU mapping may not be keeping up.

By any chance have you tried changing the settings with the Bavarian jumper mod active after you put on the aftermarket exhaust?

 

[ionbeam]

Time to get serious and bring in someone that can cure your FJR's problems.

BTW, just unplug the O2 sensor to confirm that it's not causing the problem.

The last time, we threw ignition coils, fuel injector harness, ECU, O2 sensor at it...No happiness until a new to me TB assembly

So, you have replaced the high voltage ignition system, the fuel/ignition controlling computer, the fuel delivery system and an irrelevant O2 sensor yet the problem persists. You see the issue at Cyl #1 & #2, those cylinders are fired by different coils (which have been replaced) and the fuel system has been replaced. The only sensors that could affect certain cylinders would be the crank sensor and the timing sensor. If you have a stock catalytic converter it has a common phylum which mixes all the cylinders exhaust together so what you feel as exhaust flow out the tail pipes isn't related to right/left exhaust headers. There is even a balancer cross over pipe between Cyl #2 & #3 (at least on the gen 1). About the only thing left to cause the running issue is a mechanic failure, change the mechanic.

When you changed the throttle bodies your FJR ran normal for a while. You touched/moved/disturbed something in that process. Since the issue went away and the exact same symptom came back it is highly unlikely that you have had the same failure caused by two entirely different assemblies. Perhaps you have killed two different assemblies the same way causing them to fail the same way. Or, you caused the symptoms to go away by 'messing' with stuff and it has just jostled back out of alignment with the cosmos.

 

[st4gary]

Any chance it could be a fuel pressure/pump issue? It's been a couple of years since I've been under the tank, I can't recall if the fuel system has a port to check/monitor the fuel pressure or not.

 

[dcarver]

.

 

[dcarver]

I had very similar symptoms on my Honda V65. Turned out that the ignition coils were breaking down under heat and load. They would fire, but not as well as they should. It ran slightly rougher than it did before hand especially just off idle, fuel economy went to crap, I couldn't keep a set of plugs in it for more than a few hundred miles before they would crud up. On this one, new coils made it good again.

NTXFJR - I sure was hoping that was the cause last time this happened. Same symptoms with two new coils installed.

If you still have crap in the fuel system as a result of the auxiliary tank issue, the replaced TB might now be screwed for the same reason - fine particulates floating around. Fuel injectors have a fine mesh (generally replaceable) screen or filter basket at the inlet. Some minor surgery to have a look might be worthwhile. Perhaps a quick dunk of the filters in an ultrasonic tank is worthwhile.

I think you're on it, Ross. Thinking back on it, the issue returned after having run a fresh load of fuel from the aux tank. I had the tank off for repair - cut the top off, remove baffles, re-weld top back on, stuff with fuel cell foam, install, use tank. Shortly thereafter, issues.

Any difference to the symptom when stone cold vs fully warmed up?

Fred - Not really. The popping (very slightly) diminishes when warm but still, obviously sick.

Does the misfiring when the engine is cold happen in a similar manor with the stock exhaust? If so, the aftermarket exhaust may be flowing a bit more than stock, and when cold the stock ECU mapping may not be keeping up.By any chance have you tried changing the settings with the Bavarian jumper mod active after you put on the aftermarket exhaust?

NBB - The Barbarian mode, I've read, only impacts idle and slightly off idle, IIRC. This miss is at all rpm's although it is masked somewhat at higher rpms.

Time to get serious and bring in someone that can cure your FJR's problems.

BTW, just unplug the O2 sensor to confirm that it's not causing the problem.

The last time, we threw ignition coils, fuel injector harness, ECU, O2 sensor at it...No happiness until a new to me TB assembly

So, you have replaced the high voltage ignition system, the fuel/ignition controlling computer, the fuel delivery system and an irrelevant O2 sensor yet the problem persists. You see the issue at Cyl #1 & #2, those cylinders are fired by different coils (which have been replaced) and the fuel system has been replaced. The only sensors that could affect certain cylinders would be the crank sensor and the timing sensor. If you have a stock catalytic converter it has a common phylum which mixes all the cylinders exhaust together so what you feel as exhaust flow out the tail pipes isn't related to right/left exhaust headers. There is even a balancer cross over pipe between Cyl #2 & #3 (at least on the gen 1). About the only thing left to cause the running issue is a mechanic failure, change the mechanic.

When you changed the throttle bodies your FJR ran normal for a while. You touched/moved/disturbed something in that process. Since the issue went away and the exact same symptom came back it is highly unlikely that you have had the same failure caused by two entirely different assemblies. Perhaps you have killed two different assemblies the same way causing them to fail the same way. Or, you caused the symptoms to go away by 'messing' with stuff and it has just jostled back out of alignment with the cosmos.

Ionbeam - I think you and Ross are on it. My bet is the same JBWeld contaminated tank has affected 9 injectors now.

Any chance it could be a fuel pressure/pump issue? It's been a couple of years since I've been under the tank, I can't recall if the fuel system has a port to check/monitor the fuel pressure or not.

St4Gary - I don't think so. We had the same symptoms when the fuel was being delivered by a Motion Pro fueling station in the shop.

---------

Here's a data point that might support RossK's theory. The injector clearly has 4 discharge holes. When I tested all injectors (which have been exposed to the potentially contaminated fuel) only two ports are discharging flow.

https://vimeo.com/161416886

One would think all 4 ports should be discharging. I wonder if all ports are the same diameter (smaller diameter clogs first?). I would ASSume that all ports operate at the same 40 psig fuel pp pressure meaning my substantially less pressure from the syringe should result in an equal, although reduced volume, flow.

I ebayed a nice 2008 TB assembly for 200 bucks. It should work nice with my 2008 engine inside the 2006 frame.

Gents, Thank You all very much for the insights. Especially Dr. Ionbeam. As of now I'm recruiting for a mechanic! How come that Ray guy has to live so far away, anyway?