wierd problem

[pnkrkr4lif]

OK, so I'm stumped and both mechanics at the dealer are stumped too. I have had the bike for a month, it has 31,000 miles on it. I put a power commander V on it and uploaded a map from their website, I also have Delkevic mufflers. It has worked flawlessly the entire time. I was able to get my bike in for the valve clearance check

I get the bike back on a thursday, by saturday it started to run kind of weird, if I hold the throttle at a steady speed it starts to buck a little and it sounds a little off. So I cut my ride short and head home to check things out. For kicks I hooked up my TBS motion pro tool and was surprised to find them out of sync because the tech has some fancy digital machine and got them perfect.

I re-synced the throttle bodies and everything was fine, until monday. I started getting the same problem at low RPMs the bike would buck and hesitate. So when I got home I rechecked the throttle bodies and they were out of sync again. So I re-synced them again and off for a test ride. Everything seemed to be working fine.

Then on wednesday same problem, rechecked the throttle bodies and out of sync again! So I took the bike back to the dealer and they have been looking at it for a few days now and say they can't find anything wrong. I have also lost 2-3 miles per gallon through this whole thing.

any ideas?!?

 

[Hornet Pilot]

I would first try disconnecting the Power Commander and see how it runs. I have had problems in the past when they start to fail. However, that said, it shouldn't have affected the sync of your throttle bodies I don't think.

 

[pnkrkr4lif]

what is stumping me is why do they un-sync within a tank of fuel. I thought about unplugging the PC-V and start from scratch. Problem is that I would need to have sent it back today to Amazon if in fact it is faulty. But if it's defective I should be able to exchange it from Amazon also. The lead tech said he will tune the PC-V himself to see if that would also help.

 

[FredandJeannesRacer]

It might be something else, If the bike ran flawlessly BEFORE you got the valve clearence checked.

 

[pnkrkr4lif]

Kind think they might have pinched a vacuum line or something. He said all valves checked within spec, so not sure what else there is. He also said he was going to re sync the butterflies

 

[bluesdog]

Check the PC-V ground wire.

 

[Twigg]

Is it the same cylinders going out of sync? By how much? We fret about this issue but for the most part it really only affects the bike at idle unless they are way off.

Out of sync throttle bodies shouldn't cause much in the way of noticeable "bucking" unless the problem was severe, and then you would notice it at idle.

 

[chornbe]

OK, so I'm stumped and both mechanics at the dealer are stumped too. I have had the bike for a month, it has 31,000 miles on it. I put a power commander V on it and uploaded a map from their website, I also have Delkevic mufflers. It has worked flawlessly the entire time. I was able to get my bike in for the valve clearance check
I get the bike back on a thursday, by saturday it started to run kind of weird, if I hold the throttle at a steady speed it starts to buck a little and it sounds a little off. So I cut my ride short and head home to check things out. For kicks I hooked up my TBS motion pro tool and was surprised to find them out of sync because the tech has some fancy digital machine and got them perfect.

I re-synced the throttle bodies and everything was fine, until monday. I started getting the same problem at low RPMs the bike would buck and hesitate. So when I got home I rechecked the throttle bodies and they were out of sync again. So I re-synced them again and off for a test ride. Everything seemed to be working fine.

Then on wednesday same problem, rechecked the throttle bodies and out of sync again! So I took the bike back to the dealer and they have been looking at it for a few days now and say they can't find anything wrong. I have also lost 2-3 miles per gallon through this whole thing.

any ideas?!?

You actually trust that a dealer did a valve check properly, or at all? I'd start there.

$.02

 

[rbentnail]

Sounds like the timing chain is off a tooth.

 

[RossKean]

Sounds like the timing chain is off a tooth.

Based upon the symptoms, I agree. If the dealer did the valve check and found no need for adjustment and didn't do something like change a CCT then it seems unlikely that he would have done anything to cause a skipped tooth. To do just a valve CHECK, the cams and chain are not touched.

Assuming the dealer did not actually remove the cams or loosen the chain to replace a CCT, I would first of all look for pinched, torn or loose vacuum lines. Next, I would remove the Power Commander from the equation (and the bike) and try it again.

 

[Denver_FJR]

I would first try disconnecting the Power Commander and see how it runs. I have had problems in the past when they start to fail. However, that said, it shouldn't have affected the sync of your throttle bodies I don't think.

I've always wondered if fuel modifications such as BJM or Power Commander install could have an effect on vacuum and be apparent during TBS. After all you're offsetting air volume with fuel.

 

[Fred W]

Power Commanders are capable of sending different maps to the different cylinders. Normally we do not do that on an FJR and just use the same map for all 4. But that points out the possibility of the PC causing a misbalance between cylinders.

I'd bypass the PCIII and see what happens. If it is defective, even if the retailer won't cover i, DynaTune should still cover it under warranty. Do be sure the ground wire is run all the way back to the battery negative terminal (not just frame ground)

 

[pnkrkr4lif]

The thing ran fantastic before I took it to the shop. I consistently averaging 39MPG with the tune I was running. I did the TBS when I first got the bike and I haven't had to adjust them since. After I got it back I was getting around 35MPG and then the running issue ever 2 days. So the day I gave it back I had my sync tool hooked up, tightened up my throttle lock and took the bike up to 3000 RPMs. You could hear the thing missing and stuttering, the fluid in the tool were pretty close for a while then they would go out of wack for a bit then level back out then out of wack. The entire time I had that thing steady at 3K, it sounded terrible. Also, when I took off the PAIR stuff I never adjusted the idle back up so the thing would idle around 850RPM, some times after the cold start warm up it would idle down a little to far and stall. When I got it back I bumped up the idle using the screw on the right side of the frame and brought it up to about 1030RPMs. (could that have been what doomed me?)

 

[Richouse]

Has all of this been happening on one tank of gas? Bad gas maybe???

 

[pnkrkr4lif]

3 tanks and 2 different gas brands

 

[rbentnail]

The thing ran fantastic before I took it to the shop. I consistently averaging 39MPG with the tune I was running. I did the TBS when I first got the bike and I haven't had to adjust them since. After I got it back I was getting around 35MPG and then the running issue ever 2 days. So the day I gave it back I had my sync tool hooked up, tightened up my throttle lock and took the bike up to 3000 RPMs. You could hear the thing missing and stuttering, the fluid in the tool were pretty close for a while then they would go out of wack for a bit then level back out then out of wack. The entire time I had that thing steady at 3K, it sounded terrible. Also, when I took off the PAIR stuff I never adjusted the idle back up so the thing would idle around 850RPM, some times after the cold start warm up it would idle down a little to far and stall. When I got it back I bumped up the idle using the screw on the right side of the frame and brought it up to about 1030RPMs. (could that have been what doomed me?)

Skipping a tooth on the timing chain did similar on my bike: the idle rate plummeted and screwing the idle screw all the way in barely got it back to 1000. Just barely but no higher. Running above about 4k rpm it was fine but less than that was very rough- coughing, missing, spitting, whatever you want to call it. It just ran crappy. And check your fuel tank vent tube, it might be kinked. It's the hose that runs from the rear left of the tank straight down to the universal joint cover behind the left footpeg. It's easy to kink it, please DAMHIK.

You said in the OP that "I was able to get my bike in for the valve clearance check" but haven't said if re-shimming was necessary. As inferred in post #10, I think you need to find out exactly what the shop did and didn't do.

 

[pnkrkr4lif]

The tech told me that all valves were in spec and no shimming was needed, but when the shop opens tomorrow I will see if they took enough apart to mess with the timing

 

[Bustanut joker]

Timing doesn't make sense to me... If it was timing his re synching the TB and getting it to run fine after would indicate to me it was something else.

As several here have suggested i'd disconnect the PC and check for vacuum leak.

 

[Intech]

Timing doesn't make sense to me... If it was timing his re synching the TB and getting it to run fine after would indicate to me it was something else.As several here have suggested i'd disconnect the PC and check for vacuum leak.

Damn! Barry being all business and shit!! Historic!

(No sheep were harmed in the creation of this post)