2007 rough, slow cold idle

Well I finally made time to come back to this project and see what I could figure out. I am a little surprised as to how backing out the TB adjustment screws so much really didn't make the readings to far off of what the manual says everything should be at.

Ok, to start off my idle adjustment screw was all the way in and the bike would idle right at 1k, probably just a touch under. With my mercury gauge hooked up and the bike warmed up and idling at 1kish, all four cylinders showed approximately 24 cmHg (the manual says 33.3 kPg or 250 mmHg, for this write up I will be using cmHg because that is what my gauge reads in).

The first thing I did was turn the #3 TB adjustment screw two good turns out. The mercury dropped to 20.5 cmHg. Since I was already on the right side of the bike I also adjusted #4 down to match. Upon moving #4 the idle came up on the bike. At this point I have two cylinders showing much less vacuum then the manual specifies. I was starting to think that I was going to be way off from were I should be once I got done with this experiment. I went ahead and adjusted 1 and 2 to match 3 and 4. At this point the tach is showing about 1200 rpm.

Now I adjust the idle back a touch to what I think is 1100 rpm......look down at the mercury gauge and what do you know, I'm reading right at 24 cmHg again on all the cylinders! Great! I decided that since this was working out well so far I was going to back out the TB adj. screws some more. Basically I wanted to be able to make 1100 rpm the center of my idle adjustment range since I felt that was were I wanted my bike to be at to hopefully minimize the issues coming off of high idle in as the bike warms in the mornings. After I went through the whole process one more time I did get the rpms to rise a little more.

As of right now, I read 24 cmHg on all four cylinders and I can now adjust my idle from about 1600-1650 to 800 rpm, so a much better range. Originally my TB adj. screws were almost all the way down. If you look at them now, the heads of the screws are close to level with the opening surface. I have never had the bike adjusted by a shop, so I assume that #3 was that way from Yamaha (+ or - any movement over time).

So, in my particular case I believed that if I could get another 100 rpm of idle speed, my bike would be ok. Since the ECU recall the only issues I am having is when the bike comes off of high idle as it warms in the mornings. After my tune up at the first of the month I got it past actually stalling during that time and to the point that is just almost stalls. Tomorrow morning might not be the best morning to tell if the touch of extra idle rpm makes this little hiccup in the ECU controls (thats what I'm blaming it all on since it wasn't there with the original ECU!) tolerable and hopefully fairly unnoticeable as the temps are not supposed to drop to much tonight (70's). However, it sounds like Friday morning will be cooler (low 60s maybe upper 50s that morning).

So Twistedcricket, I'll let you know if my bike is adjusted out in a couple of days. I would imagine that if this fixes mine, yours has got to be close since worldbound4now did the same stuff I just did. The only difference might possibly be how much he backed the TB adj screws out. What does your bike idle at when it shows four bars on the temp gauge?

Metric,

It sounds like we did similar procedures, except I did not turn out the TB screw on #3 as much as you did. I was tempted to redo it, but we ran out of time and had other "to-do" items on the list.

Twistedcricket, hit up someone with a TBS tuning tool and start with #3 cylinder out farther than what I have it at (maybe at 2 turns counterclockwise from fully closed clockwise) and then balance the rest to #3. Don't forget to open the throttle for a second or so after "balancing" each cylinder and adjusting your idle speed after each TB adjustment to keep yourself at an 1000-1100 rpm hot idle speed. I'd try that before trying the ECU attempt that you emailed me about (swap back to the recalled ECU).

worldbound4now

Well, summer has officially set in. I don't think there are going to be anymore 50-60 degree mornings until this fall. However, after a few cold starts and few more miles, I'm pretty confident that I have the ol' girl adjusted out finally. Its noticably smoother at start up and there are zero stumbles as it warms now. I'm closing the book on this project and officially saying my bike is fixed.

It would be interesting to know how many other people have this issue with the new ECU's though. I'm also wondering if maybe some of this wasn't caused by a 'programming' change in all new ECU's to include new bikes. I've seen people talking about similar problems with the '09's. Makes me think maybe Yamaha has done some 'tuning' recently, maybe trying to comply with some new emmisions standards or something. Its just something I've been wondering about.

I would but I don't know of anyone local who has a TBS tool... maybe there's a trip back to Dallas sometime in the fall

Just found this thread and am very curious about the cold start high idle mechanism. This came up in another thread where I was completely unaware of its existence. Did anyone ever figure out what the deal is with that? How does it work?

It sounds like it is a vacuum operated device of some sort but how does the ECU control it?

Or is the vacuum device itself somehow temperature controlled?

Knowing more about this cold start thingee may lead to the root cause of these problems.

The cold fast-idle control simply uses a thermo-wax element to vary the amount of throttle body bypass air based on the coolant temperature. Once the engine reaches operating temperature the bypass air valve on each throttle body should be fully closed.

The coolant circulates continuously through the thermo-wax device located below the leftmost throttle bodies. The small hose connected to the coolant pipe manifold above the engine carries the hot coolant down to the wax control unit. After the coolant passes through the control unit it flows back to the left end of the radiator.

https://en.wikipedia.org/wiki/Wax_motor

The thermo-wax device is a linear actuator moving the bypass air valves on each throttle body.

The ECU doesn't control the cold fast-idle. It just responds to the coolant temperature and intake air pressure when the air bypass valves are open at a cold start. With the bypass valves open or partially open the ECU responds as if the throttle valves have been opened -- more fuel is delivered and a higher idle results. Also the ECU provides additional warm-up fuel enrichment based on coolant temperature.

Ah, OK. So it works the same as a coolant thermostat. In which case, there is a good chance that the device would go tits up and not open the high idle passage properly or enough. Now to scour the parts lists for a replacement. It has to be in there somewhere...

OK, found it. Here:



It appears that there is a spring which should pull the sliding rail to the right in that picture (left when seated on bike) which should open up the high idle pistons. If they are not opening enough it could be that the spring is too wimpy or that the thermowax is not contracting enough to allow the rail to slide. If you can push it open with a finger and then it stays there, it would make sense that maybe the spring is too soft? If it returns to it's less open position then the actuator would be at fault.

The bad news is there doesn't seem to be separate part numbers for any of this stuff. It's a part of the throttle body assembly.

The good news is that this would be really easy to put a "choke" cable on if someone wanted to manually control their high idle.

FredW ~ Nice find on the parts diagram! Isn't it FUN when they don't offer the individual parts, but only the complete ass'y? Don't suppose there is "profit incentive" in the equation somewhere, do ya? :angry2:

Just looking at the drawing, and that rather wimpy looking return spring, do you suppose that the accumulation of swarf in the sliding rail could cause enough resistance to freely sliding that it could cause a problem? I have no way of knowing what kind of force that temperature sensitive "Wax motor" might be capable of generating, and that whole assy lives in a pretty harsh environment... just sayin.

You know, the more I read the factory SM, the less happy I am at myself for having drunk the Kool Aid and buying the damn thing. No Index, descriptions for procedures that tell you to remove a lot of items that aren't really necessary, telling you to use Yamaha Tool Number "X", etc. This, and other model specific forums online are a much better source of valid information. To me, about all the factory SM is good for is to confirm that I'm not about to totally Screw The Pooch too badly when I try to work on the bike.

Really valid and helpful information is right here, on good ol FJRforum.com.

And thanks to everyone who contributes to the discussions and help to make it that way! :clapping: Youse are good peeps! :yahoo:

Don

dsmack said:

FredW ~ Nice find on the parts diagram! Isn't it FUN when they don't offer the individual parts, but only the complete ass'y? Don't suppose there is "profit incentive" in the equation somewhere, do ya? :angry2:
Just looking at the drawing, and that rather wimpy looking return spring, do you suppose that the accumulation of swarf in the sliding rail could cause enough resistance to freely sliding that it could cause a problem? I have no way of knowing what kind of force that temperature sensitive "Wax motor" might be capable of generating, and that whole assy lives in a pretty harsh environment... just sayin.

Click to expand...

Well, based on the lack of prior discussion here on the forum related to this cold start function, I'd say it's a pretty reliable widget. So it's probably OK that they didn't break down all of these parts, though the wax motor as a FRU sure would be nice.

For this problem, (the failure of the cold idle pistons to open enough when cold) the problem wouldn't be whether the wax motor has enough gusto, as its function is just to push them closed when warm. The Wimpy Spring ® would be the suspect. But, as I alluded before, if that was the entire problem then you'd expect that you could just push it open and it would stay there until the engine warmed up again. I'm thinking this will turn out to be something related to the wax motor malfunctioning.

I definetly understand the thought process here, and I understand why you are looking at the part that you are. However, somehow the ECU is responsible for the problem that my bike had. Not the issue with not being able to adjust the idle any higher then 1k obviously, but the warm up issue in the morning definetly.

I ride my bike all winter (I mention this because I want anyone reading this to realize that the bike had not sat still for any extended periods of time, I was very familiar with how the bike ran and it hadn't sat and had something get plugged up or seized during the winter) and early this spring I took it into the dealer for the key switch recall. While I was there they checked to see if there were any other recalls that needed to be addressed. The ECU showed up for my bike. Mind you the bike ran like a top up until this point. I talked to them about why the ECU recall needed to be done and decided to go ahead since they had one in stock. Aside from the new ignition switch, the only thing they changed was the ECU. From that point on, I had idle issues when the bike was warming in the mornings. To me, this points squarely at the ECU.

I've seen that some people are complaining about idle issues with the '09s. When I listen to those claims and compare my issues, it seems to me that Yamaha has made some sort of change in the ECU and how it controls something. I don't know why but my guess is probably for some new emission standard that has come into affect they needed to meet. Unfortunately it seems that maybe they also implemented the change in the ECU's being used for recalls.

All that being said, after some work, my bike is now running the best that is has since I purchased it. Running down the highway at 4k I can't even tell the motor is running it is so smooth....I was laughing about it going down the road after I finally got it right. At least in my case, it seems that the bikes can be tuned out to run very nicely without replaceing anything. If in fact there is an issue with the parts you are looking at right now, I suppose time will tell. If everything I did covered up an issue with one of those parts, then eventually the problem will come back around as the parts get worse. Only time will tell I guess.

You may well be right about the ECU.

My focusing on the fast idle mechanism was based on the reports that after starting their bikes when cold the engine was only running at (or below) 1000 rpm and was clunking and sputtering.

On a cold start, at least with the 1st gen bikes, the engine runs at around twice that speed (~2000 rpm) until it begins to warm up.

Fred W said:

You may well be right about the ECU.
My focusing on the fast idle mechanism was based on the reports that after starting their bikes when cold the engine was only running at (or below) 1000 rpm and was clunking and sputtering.

On a cold start, at least with the 1st gen bikes, the engine runs at around twice that speed (~2000 rpm) until it begins to warm up.

Click to expand...

Mine has never idled that high at start up. Mine is at about 1500 rpm for high idle. Then once it warms it comes down to 1100. I think that you are correct that the Gen I bikes do idle higher when cold, I have seen this first hand also.

Fred W said:

You may well be right about the ECU.
My focusing on the fast idle mechanism was based on the reports that after starting their bikes when cold the engine was only running at (or below) 1000 rpm and was clunking and sputtering.

On a cold start, at least with the 1st gen bikes, the engine runs at around twice that speed (~2000 rpm) until it begins to warm up.

Click to expand...

I'm just now seeing this thread. Very interesting because my 08 has a slower idle and makes the clunking noise at cold start. As Fred states about the gen 1 bikes, my old 04 idled around 2000 rpm with no clunks at cold start. I've kind of been concened about any damage this might be causing on the 08. It sure doesn't sound good. I'm getting ready to take the 08 in for the ignition switch recall and some other warrany related work. It would be nice if the techs at my dealership knew something about this, but my guess is that they don't. If it is a ECU problem, you would have to pay for and change that out yourself. Correct? I've already done a TB sync and don't recall a bottomed out screw, but I really wasn't turning them enough to tell. Thanks for the info so far. Keep it coming.

GP

I just went out and checked. Mine starts and runs at 2100 rpm on the tach when cold.

Fred W said:

I just went out and checked. Mine starts and runs at 2100 rpm on the tach when cold.

Click to expand...

I forgot to mention at cold start up, my 08 idles at 800-1000 rpm. (Clunk, clunk, clunk......................)

GP

GPRIDER said:

Fred W said:

I just went out and checked. Mine starts and runs at 2100 rpm on the tach when cold.

Click to expand...

I forgot to mention at cold start up, my 08 idles at 800-1000 rpm. (Clunk, clunk, clunk......................)

GP

Click to expand...

Wow!

Interesting to read about the thermo-wax device. If it is supposed to move, be sure it's clean. I wouldn't lubricate with any wet lube because a liquid lubricant will hold dirt making things worse in the long run.

The ECU needs to have a correct coolant temperature reading to provide a richer fuel trim for cold starts. To check coolant temperature go to the diAG mode, then press SELECT until you are at Code 06. Read the coolant temperature in °C. If the bike has sat over night or for several days, the reading should be essentially the same as ambient. If it reads way to cold the initial FI trim will be too rich, if the reading is too high the FI trim will be too lean. Next time you return from riding and the engine is fully warmed up check this value again and it should reflect full coolant temperature, someplace between 87°C and 102°C degrees.

Instructions & codes.

Can you feel the love?

One other thing that would pretty easy to check, and may lend some additional information, would be to measure the physical position of the wax motor actuator or, more to the point, the fast idle pistons on the throttle bodies, both when the engine is stone cold and then later after it warms up. Make sure those suckers are being moved. They may be stuck (partially) open and then folks are cranking down the other adjustments to compensate.

"Rough, slow and cold" - sounds like my mother-in-law!

So, guys, help me get my head around this "wax motor" thingie...

When the motor is cold, the wax in the "motor" is solid, and the spring pulls the rail all the way to the left side of the motor, thereby pulling open the "fast idle" valves on the throttle bodies. That's what I just determined looking at the throttle bodies on my very cold (read: dead) FJR.

So what happens? I'm guessing when the bike heats up and hot coolant flows thru the tubes leading to the mechanism, the wax melts in its "piston", expands with the heat and forces the sliding rail back towards the right side of the bike (left side in Fred W's illustration) allowing the fast idle valves to close?

Does this sequence of events sound about right?

One thing I could not determine with the throttle bodies still mounted on the head, and you can NOT see the "wax motor" thingie, is if there is an adjusting mechanism on the wax motor, which might let the sliding rail retract further at a cold-motor state, opening the fast idle valves further.

It appears, though certainly not conclusive from the photo, that there might be an adjustment to the mechanism:



The photo doesn't zoom well, but here it is "closer":



That appears to be an adjustment screw to me. But how would you get to it without removing the throttle bodies, I don't have a clue.

Anyway, it appears late-model Gen IIs with slow "fast idles" might be adjustable.

Anyone got there throttle bodies off to confirm???

'Howie