Rough Idle, Power issues, Fuel etc.

[ionbeam]

...Have a look at my post on a possibly shorted oxygen sensor. The wire was significantly pinched when the crank...t if that doesn't pan out, based just on ionbeam's prior suggestions/comments it might be worthwhile to check to be sure that the cold start enricheners on the throttle bodies are not getting stuck. These are the little piston like dealios in the front of each throttle body...

I've PMed Ross. Given him info on the pinched wire, if there was one of four wires to pinch, they got the right one. As far as the 'cold start enrichners' they are additional air bleeds to supplement the ECU Fuel Enrichment. I was beguiled by their roll but they are about air and not gas.

There may have been some issues with diAG readings being MKS and not inch/pound/Fahrenheit.

 

[Fred W]

I've PMed Ross. Given him info on the pinched wire, if there was one of four wires to pinch, they got the right one.

I also PM'ed Ross and suggested just disconnecting the O2 sensor to see how it runs. If the symptoms change significantly (not necesarily improve completely) he might be on to something. Many bikes with PCIII's are running with no O2 sensors and with a zero map installed they will run considerably better than his does, especially at idle.

As far as the 'cold start enrichners' they are additional air bleeds to supplement the ECU Fuel Enrichment. I was beguiled by their roll but they are about air and not gas.

Yeah that's true. If it was a carb they'd be enrichners. On F.I. all they can pass is air. Doh! Guess I had not thought that through completely. :blush:

 

[03HiYoSilver]

Ross,

Check those Small Wires on your Throttle Body Assy and make sure they are not Pinched/Cut/or Shorting out against a metal surface.

I had a similar problem but it was #4 that would NOT adjust and Idled Roughly. After doing many fixes to NO avail under YES, ended up having to replace the Throttle Body Assy (which is all 4 Bodies...not done separately). I along with the Yamaha CSR, ordered it from Japan to have it on hand...when they gave up on all their options, they decided to install this Throttle Body Assy and to their surprise, it WORKED!

This is RARE and this Condition will not throw a Code either.

This ended up to be my Fix for this situation.

Hopefully, yours will not have to come to this and good luck on your fix.

 

[RossKean]

DONE!

FIXED! (I think)

After a whole bunch of stuff, the bike is running properly! (at least as far as I can tell with a quick run around the block during a brief lull in the heavy rain).

I did a lot of checking but never found anything that appeared to be a problem. Cam timing was good, valve check was good, plugs, plug caps, air filter, coil ohm readings, fuel tank examination for crud, possible corrosion in ECU connector, Vacuum leaks, Diagnostic checks, TBS, various other connectors etc etc. etc. did not show anything out of the ordinary.

The only thing that was odd was my discovery of an O2 sensor wire that had been pinched between the crankcase cover and the chassis; probably when we replaced the CCT at NERDs in Stowe Vt. (May have happened before?) One of the wires (white one) was squished enough that the insulation was split and may have been making electrical contact with the bike chassis. In any case, when I put it all back together, it started easily, idled smoothly and throttle was responsive below 2000 rpm again. Exhaust doesn't smell like an EPA disaster site anymore either.

I'm reserving final judgement until I have had a chance to take it for a real ride in a day or two. I'll see if performance stays up there and keep an eye on fuel consumption before I can definitively state that its a done deal.

Many thanks to everyone who contributed to the trouble shooting and resolution to this elusive problem.

At least I don't owe dcarver money (or beer) since the ECU connector and pins were absolutely pristine and dry!

Ross

Edit: Got out for 60 miles of mixed city/highway tonight. Behaved perfectly - as well as it has ever run. Fuel economy is back and no more stumbling at low rpm. Complete transformation! I may have to go out and buy it a present in celebration. I KNOW it would love to have a new Zumo!

 

[graytaz]

Isn't technology grand. Something so seemingly insignificant can have such negative repercussions. Glad to hear that you located the problem and that it was an inexpensive fix, if you discount all the time and energy involved. Also on the bright side, your valve clearance check is complete along with a coolant change. You can tick those off the todo list.

Did Irene hit your area very hard?

Philip

 

[RossKean]

Isn't technology grand. Something so seemingly insignificant can have such negative repercussions. Glad to hear that you located the problem and that it was an inexpensive fix, if you discount all the time and energy involved. Also on the bright side, your valve clearance check is complete along with a coolant change. You can tick those off the todo list.

Did Irene hit your area very hard?

Philip

Irene was kind to us compared to some parts of New England. Heavy rain for a day but probably less than 3". A bit windy but not wild.

Valve check is done but I didn't even bother to change coolant - it was done last year and once every 2 years should be plenty. I did manage to learn quite a bit about the bike throughout the whole process. If I had to pay the dealer for the amount of time I spent on it, it would have been pretty expensive!

 

[dcarver]

At least I don't owe dcarver money (or beer) since the ECU connector and pins were absolutely pristine and dry!

Very good to hear you fixed it Ross :clapping: I know it's no fun when the skoot isn't running right and you're miles away from home. I'll store this in the fjr database as another point of technical reference. And I'll buy you the beer!

EDIT - wait a minute, wasn't the bike running poorly *before* tech day and fairing removal? :huh:

 

[RossKean]

At least I don't owe dcarver money (or beer) since the ECU connector and pins were absolutely pristine and dry!

Very good to hear you fixed it Ross :clapping: I know it's no fun when the skoot isn't running right and you're miles away from home. I'll store this in the fjr database as another point of technical reference. And I'll buy you the beer!

EDIT - wait a minute, wasn't the bike running poorly *before* tech day and fairing removal? :huh:

It was and the reason is a bit of a mystery. I rode through several hours of rain and I thought the problem was due to wet ignition. Later examination for arcing, poor connections etc didn't reveal anything. I am thinking it may have been a tank of bad (wet) gas when I filled up in Calais. I may never know until it happens (or doesn't happen) again.

Despite some discussions on another thread regarding my grounded O2 sensor, I am convinced that this was the cause of the post-CCT problem. After MANY hours of working on the bike, this is the ONLY thing that I changed that could have made any difference.

Ross

 

[dcarver]

I think the only real solution is for you to ride into a huge rain storm and see if the symptoms reoccur.

Something like this..

Many times, it's multiple issues causing a problem.

..and sometimes, it's never fully resolved.

If the bike is running good, ride it.

If the problem happens again, deal with it then.

Just ride Ross, just Ride!

 

[Fred W]

Despite some discussions on another thread regarding my grounded O2 sensor, I am convinced that this was the cause of the post-CCT problem. After MANY hours of working on the bike, this is the ONLY thing that I changed that could have made any difference.

Ross

Was the O2 sensor wire definitely pinched during the re-assembly? What was it "pinched" between?

What I'm getting at is, could it have been pinched and or chafed earlier? If the insulation was already chafed bare then the rain water could have completed the circuit to ground.

 

[RossKean]

Despite some discussions on another thread regarding my grounded O2 sensor, I am convinced that this was the cause of the post-CCT problem. After MANY hours of working on the bike, this is the ONLY thing that I changed that could have made any difference.

Ross

Was the O2 sensor wire definitely pinched during the re-assembly? What was it "pinched" between?

What I'm getting at is, could it have been pinched and or chafed earlier? If the insulation was already chafed bare then the rain water could have completed the circuit to ground.

I don't have any idea. It was between the oil pump cover and the case but the condition of the wire was not noticed until re-assembly. I would like to think it was a pre-existing condition but I think we would have noticed during re-assembly after doing the CCT. Since there isn't anything I can do until it happens (or doesn't happen) again, I'm just going to keep an eye on it and ride anyway.

Ross