Idle Adjustment Question

[FJR Flyer]

I realize its friday, and I've had a couple beers, but here it goes.

I did a TBS today. First one on the FJR (did many on the FJ). No big issues with the TBS. But....my idle is right at 1000 rpm. I tried to move it up a bit and realized the adjustment screw is all the way in. The spring is completely compressed and there is no adjustment left, at least to go higher. Of course, it will go lower.

I'm guessing this falls outside the norm. Any ideas on what's up? I'm running a PCIII, but I don't think that would have any effect on idle.

I will say the TBS was really easy. Now, changing tires on 12" camper rims is a royal PITA. I will never do that again.

 

[RsvlFeej]

My guess is your baseline (#3) throttle body wasn't open (or closed?) enough when you did your TBS. When you matched the other throttle bodies to #3, you ran yourself out of idle adjustment.

Good thing you thought the TBS was easy, because you get to do another one.

Actually, while you're in there, you may as well do the "completely unauthorized TBS", which matches intake at an RPM of your choice. Here's a link:

https://www.fjrforum.com/forum//index.php?showtopic=23101&st=0&p=271779&hl=unauthorized&fromsearch=1entry271779

 

[03HiYoSilver]

FJR,

One thing that may help you is to Screw all the Air Adjustments Screws down and Back them out to about 1 Turn - 1 1/2 Turns out.

This will set a new Baseline on your #3 Screw. Then do a New TBS and should recover your Idle Adjustment.

 

[RadioHowie]

Yep...what they said.

Basically, the 4 TBS adjustment screws can be considered individual throttle body idle adjustments. If you start your TBS with them screwed in too far, you have to run the main idle adjuster, under the right side of the tank, in farther to maintain 1100rpm.

You have experienced what many have...you lost your main adjustment by closing down the TBS adjusters too much.

Now, how to fix it? Pretty easy...turn each individual TBS set screw out EXACTLY 1/2 a turn for each screw. The key is to back each screw out an equal amount. When you do so, your idle speed will increase. THEN, you can return to your normal idle with the main adjuster.

You MAY want to re-check your TBS settings after accomplishing this, but assuming you moved all 4 an equal amount, your TBS vacuums shouldn't have changed. It may take more than a 1/2 turn on the individual set screws to get enough idle to be able to back down the overall idle with the main adjuster. The key is to move each screw an equal amount when compared to each other.

 

[FJR Flyer]

Thanks for the replies. Interesting thing is I tried to adjust the idle before I ever touched the carb adjustment screws. And I found that the #1 screw was almost all the way in.

Looks like I'll be back under the tank today.

 

[FJR Flyer]

As usual, you guys nailed it. I took the plunge and did the complete 'unauthorized' TBS. The #3 and #4 plates were way off. #1 and #2 were pretty good, and #1/2 and #3/4 were pretty close. Got the idle adjustment back to normal and its running pretty smoothly.

Thanks again. This place is the sh*t for good info.