Why does my BAC screw not change idle!?
 

Ok, I am trying to figure out what to do (91 TII). My idle with out the intial set connector grounded is 750RPM +/- 40. When I ground the initial set connector it goes to 600RPM +/- 20. So I go to the BAC screw and turn it throughout its travel and it does nothing! Has anybody delt with this? I want to set my timing with the initial set connector grounded like it says in the FSM.

James

back it out and clean it?

I find that n NAs, that screw is HORRIBLY carboned.

Like take the entire screw out? I fear things shooting across the garage and never to be found. So that is cool?

James

Does your idle go up when you turn on your A/C? If not, you may have fried the transistor in the ECU.

waaaaaaaaait a minute..
to every car that i get that dies with the AC on has NEVER had a fried anything.

just poor timing, TPS and Idle adjustment

all at once.

i dont thing that the screw will have anything fly out.

My experience is on the NA cars.
theirs in in the dynamic chamber, and its oly a conical screw and o-ring.

prolly same for you.

i think itll be fine.

Well, I am going to use that idle info sheet on the teamfc3s.org page. Test the BAC everywhich way. The idle goes to 950rpm like it is supposed to with the AC on.

It is a delemia. The FSM says to set the timing with the initial set conector grounded. I ground it and the idle drops to 630rpm. Can't set timing there. Can't adjust timing. So unground the ISC and it goes to 750rpm. I adjust the timing. Would like to be able to set timing with the ISC grounded.

James

Yeah. Set the timing. Just about any rpm less than a 1000. Certainly 650 to 750. I don't think the ECU will advance the timing until around 1000rpm, give or take. When you get through, look at the timing mark while reving the engine. I think you'll see there is no advance until around 1000. With or without the initial set coupler installed, the timing can and will be set correctly. Makes no diff on way or the other. Personaly I'd be quite content with the idle you presently have, as long as the bac is reacting to any load put on it such as a/c or headlights etc.