Is there anyway to adjust this on a S4? At times under electrical load my idle will drop down to 500-600rpm then slowly recover to 750. I swapped \cleaned another (used) BAC which helped a little. TPS and idle are set.

How about the variable resistor, is the screw there under all the seal crud?

I just think 750 rpm is too low for a 18 yr old car, would rather let it idle at 1000 rpm and not worry about the idle dropping momentarily every time I stop with a/c or lights on.

 

750 is normal no matter how old the car is. 1000 seems a bit high, i guess you could bump it up to 800 or 850. 1k is a bit excessive and would just waste gas. i could never get my BAC adjusted, so i used the throttle cable to adjust base idle.

don't mess with the resistor screw. it's set from the factory and epoxy'd over to keep people like you and me from messing with it. i think it adjusts lean/rich at idle. not idle speed.

 

Great, how do you recall how you did it? On the throttle body end of things looks like it's just a linkage with a cotter pin, don't see anyway to adjust that.

 

i also have a ghetto IDLE @ 1,2k rpm... *doh*

if you have cruise control, do it like me
take the plastik cap off the Servo-motor and drop something like a screw in to get the throttle open...
if you want i can post a pic of it tommorow

 

dont use accelerator cable to raise idle
how do people get ideas like this? mental asylum?

 

You'll just about never get a consistant idle using the throttle cable to hold the plates open. It's one of the stupidest things I see people do. There's an idle stop screw there for a reason, make use of it!

 

You touch the acclr. cable it changes the idle, yeah that must be logic from a mental asylum.

Thank you for your useless response and insult.

I'm not trying to ghetto anything, on older cars many had a set screw on the cable which could be out of adjustment. The car never stalls, was looking for a mechanical way to bump up the idle a bit.

 

There's a stop screw meant just for that, instead of relying on a cable that almost never returns to the same position.

 

yes, that IS logic from mental asylum.
if the cable shook a TINY bit, the idle would change... it would never return to the same position... dont drive over any bumpy road, the idle would change too... heck, i dont even think it would return to the same rpm if you step on the gas a few times.

and there is a... gasp... throttle stop screw that would be accurate and hodl its position!

 

haha, yeah.....the screw....i'm an idiot. it's quite possible that i originally used the cable to adjust idle......and then i found the screw.

and can you give me a reason why someone would be driving down the road at idle? sounds a bit contradictory. and i doubt a tiny cable bouncing around would have enough force to move the throttle at all. considering that the cable would be taught, there would be nearly no movement to begin with.

 

They wouldn't be driving down the road at idle, but when they came to a stop the idle would never be the same, due to how quickly they let off the throttle, if they babied off of it, etc, the idle would never be very stable, it would be affected by too many variables.

 

my car idles almost perfect at like 700, when I step on the brakes it will lower to about 650 but then go back to seven, sometimes it scares me, but I trust my car.

 

EXACTly

 

my car doesn't so much drop idle as it does dim the rest of my lights when the brakes are put on. just a short slight dimming action when the brake lights get switched on.

BTW, I'll go back and recheck the throttle cable and do any adjustments as necessary.