1G High idle, smoke tested, no leaks

[edged1g]

I am trying to chase down a high idle problem(among others). I got so fed up with it, I bought a smoke machine leak detector. I pumped the intake FULL of smoke(I could tell by disconnecting the PCV hose and see it pouring out) but saw NO leaks. I am stumped at this point. The BISS is all the way in and only gets the idle to about 1000-1100 rpms.

I also tried applying vacuum to the brake booster using a hand vacuum pump with the car off to see if it was a problem. I pump it up to 20in/hg and it held there strong without dropping off.

I am looking for ideas or suggestions at this point if anyone can help. I can't get the idle down!

 

[edged1g]

Do you guys have cruise control? I found one of my cruse cables loose. After getting is properly adjusted i had to reset my throttle cable. Does the idle change is you "pull back on the throttle body butterfly (light pressure in the other direction of the way the throttle cables would pull)

MY cruise is removed with a factory non cruise control cable.

I know on hondas adjusting tps will change idle could this help

TPS is adjusted in spec. Just did that this past weekend.

This is going to sound stupid, but how much slack is there on your throttle cable? When the engine bay heats up, it tightens the cable causing it to retract on the TB a little bit.

This is strange. You really shouldn't be getting an idle that high without air getting past the throttle body.

I adjusted it to what the FSM says. Also, my idle is way too high on a cold start before the engine even heats up.

 

[BurrowZ]

Do a boost leak test from your throttle body elbow. I seriously think this has something to do with your bored throttle body.

 

[LiquidX]

While you are in link, your TPS should be 0.63v at 0% throttle. Verify that is correct and I would also suggest posting a log up as well. Your IAC should sit around 30-40 while your lrndidleadjust should be around 150 IIRC.

 

[Geier]

What are the ohm readings on your ISC?

 

[ba109296]

If your logging isc and its at 0 all the time its not right.
Try loosening your BISS a bit. Then undo your negative battery cable for around 10 minutes. Then start the car and log your isc position. Did it change? Also when its running try to loosen and tighten your biss screw. Does your isc jump around? If it does not it could be your isc driver in your ecu causing it.
But the big thing is does your isc change positions at all. And resetting it by undoing your negative battery cable for a bit.

 

[edged1g]

If your logging isc and its at 0 all the time its not right.
Try loosening your BISS a bit. Then undo your negative battery cable for around 10 minutes. Then start the car and log your isc position. Did it change? Also when its running try to loosen and tighten your biss screw. Does your isc jump around? If it does not it could be your isc driver in your ecu causing it.
But the big thing is does your isc change positions at all. And resetting it by undoing your negative battery cable for a bit.

An ISC locked at 0 means the ECU is trying to close it 100%. If thats the case then loosening your BISS would increase the idle.

I have been moving and getting situated the last 2 weekends but I will have logs and info to post up this weekend. I am dedicating this weekend to fixing this once and for all. Thanks for everyone's help.

 

[Marvin Orr]

I'm having the same issue did multiple BLT. Now I can not find a leak at all. Idle on first start warmed up too 1100 stead. Started to drive in gear at 1300 out of gear 1600 Rpms please help.