j200pruf

iTrader: (4)

Hey all, I really want to get my rebuild idleing at 750 RPM so I can set the timing and check some other stuff. I tried adjusting the screw on the top of the TB but it doesn't get teh idle low enough, is there anything else I can try on my S4 base?

trainwreck517

iTrader: (1)

Check to make sure secondary butterflys aren't open at idle.. screw in front, and make sure your *forgot whats it's called* Idle thing at the back of the TB near the fire wall is adjusted properly... Its a screw inthe lincage to control how closed the primary butterfly closes.

Kenteth

heh i cant get mine high enough.. i sit around 200...

HAILERS

Your bac's probably dead.

I'd suggest getting out a screwdriver, ratchet, 12mm socket, pair of needle nose pliers, and a download of the Fuel section of the fsm and spend just fifteen or twenty minutes wiping off the crud behind/under the throttle plates.......then make sure the throttle plates are adjusted per the fsm. And while there take note of the adjustment of the thermowax and the throttle stop screw.

Its just four nuts that hold the throttle body on and a couple of hose etc. No special tools. Common stuff.

If you pull the bac plug off and the rpm stays the same, then go here and check out the output of the ECU to the bac... http://www.teamfc3s.org/info/articles/idle.html

Kenteth

or removed

j200pruf

iTrader: (4)

Thanks for the replys, I don't have any time right now, but I think it is just that the throttle plates aren't quite closed enough. I was adjusting the screw off of the primary throttle shaft (the screw with the spring), and it got it to idle maybe 100RPM lower, but I got it all the way down to 1000RPM if I pulle up on it.

HAILERS

I probably am misunderstanding, but just in case........you don't use the screw with the spring under it to set the idle in any shape or form. That is the TPS adjusting screw to ...adjust the setting of the TPS.

But if your saying that you were lifting up on the linkage where the screw is, and the idle is dropping down when you do that, then make sure there is a touch of slack in the throttle cable. Its like you should be able to reach back there with your finger and put your finger under the cable and be able to lift the cable up and down and around at least 1/16 to 1/8th inch and not see the throttle linkage move at all.

If you have that slack...then maybe the DASHPOT needs adjsuting. Maybe try to back off the dashpot off the linkage all the way and then see what happens when you try to shut the throttle as you described in your post above. If the idle still drops when you do that..then it was not the dashpot holding the throttle plates open, so forget that idea.

Its possible the fast idle cam and screw need adjustment. That can't be done on a n/a with the throttle body on the car (near impossible anyway for me).

Maybe get some ProLine Super Lubricant or equiv and spray heavily the linkage at the front and back of the throttle body while moving the linkage. I'll get on the exaust and smoke for a few minutes after that, but not to worry.

Or it could be the thermowax/fast idle cam not falling off the roll pin because the water isn't flowing thru the thermowax good enough. Usually if that is the case, if you drive and get the engine good and heat soaked...the thermowax will expand and fall off the roll pin anyway and the idle will drop down.

Or your timing could be set too far advanced and that is causing the high idle...but probably not since you can make the idle go down when lifting on the linkage.

Who knows. A little of this and a little of that or a little of all.

If you take the bac off and the idle is 200.....it means that you need to set your idle speed. When the idle speed is set to the fsm procedure....the bac is disabled, so its more than the bac missing. That said, if the idle was set wrong, say to 200 rpm, and then the bac was again enabled, then it, the bac, would drive the rpms up to 750, or at least try to get it there. Set at 200 and having a good bac would cause some irregular bouncing of the idle at times. Enough.