Idle Mixture Screw, Plenum.

[andy-w]

Hello All...i have a slight problem with the idle screw in the plenum...i read in the bible that this should be wound right in and then unwind 2.5 turns...well i can wind mine in about half a turn an it is solid....then if i unwind it 2.5 turns and wind it back down it will only go in about half a turn again. I took the 90 deg induction hose of that goes to the plenum so i could see inside and in the air bypass outlet that goes to the stepper motor i can see what looks like a spring...is this normal as it is not mentioned in the bible.

[2 sheds]

The "spring" you are seeing is infact the thread of the idle screw (throttle by-pass). don't worry about how many turns as it has to be set up in relation to the throttle butterfly position, it has nothing to do with the stepper by-pass or mixture, it's purely a throttle butterfly by-pass, if it is running ok i would leave it as is.

Tim

[andy-w]

if i put an allen key into the top of the idle screw this spring is at 90 deg to the allen key...it is like a coiled wire that goes accross the bypass outlet that connects to the hose going to the stepper...if i was to remove the hose i would assume that you would be able to push a cloth through to clean it...i cant because of this spring or bent wire...

[2 sheds]

I don't know what you are seeing or what the spring could be ???

[GreenV8S]

Me neither - perhaps some swarf from a stripped thread? That might explain why it seems to undo OK but not do back up? I'd be tempted to take the screw right out and see what's going on in there.

[andy-w]

I'll try to take a picture and post in on here when i find out how to... but it definatley isnt swarf, it a wire that is best described as similar to a spring.

[Ballistic Banana]

Sounds to me that it may have been cross threaded and that springy thing is the old thread :C

BB

[GreenV8S]

Perhap somebody's tried to helicoil it?

[andy-w]

that would make sense, it looks just like that. i think ill get some long nosed pliers and see if it will pull out

[andy-w]

It is definately where someone has made a hash of trying to helicoil it...i took the screw right out and there is no thread in there at all.
When i took the screw out the rest of the helicoil came out with no effort at all...looks like i am going to have to get this repaired as the screw just goes right in now!!!