Idle Speed? and idle surge ?'s *Fixed*

[KGB Pilot125]

Just need to know at what RPM does the 1GA motor idle at?

I am getting really bad hunting when its cold and a really high idle after it warms up its around 1500 and if its hot out its more like 2000 RPM's.

I have cleaned the TB plate with BG spray cleaner, checked the vaccum lines and checked for intake leaks. The previous owner said he just replaced the BISS and the TB. I screwed the biss all the way in and if i remember right it should have dropped the idle and almost killed it but it didnt have any effect. Open to some suggestions.

Thanks,
Josh

 

[Loco4Life]

Should be idling at around 800 RPMs.

That's pretty weird that it's idling that high...And the base idle set screw has no affect on the car at all? You might want to just take it in and have the throttle body looked at because that aint right.

 

[KGB Pilot125]

Should be idling at around 800 RPMs.

That's pretty weird that it's idling that high...And the base idle set screw has no affect on the car at all? You might want to just take it in and have the throttle body looked at because that aint right.

Well 800 is the goal. I have a few ideas about what might be causing it. I manage a lube center that is connected to a service shop and am good friends with the ASE tech he was kinda stumped about the idle too, We just need some time to mess with it.

anyways like I said I have a few ideas about what could be causing it, I'll diagnose tomorrow after work and post up. If anyone else has any ideas let me know.

Josh

 

[steve]

The target is 750 RPM +- 50 rpm.
Excluding vacuum leaks the normal idle circuit includes the BISS, throttle plate, ISC, FIAV, and PCV. The ECU knows it should manage the idle speed by the IPS being closed. It will step the ISC in or out in an attempt to reach the target idle speed.

From cold startup until the coolant temps go above 122F the FIAV is open and once it closes the ISC and BISS control the idle speed.

Steve

 

[GSTBlack95]

I have the same freaking problem, I left on vacation for a week and I turned it over and it idled at 2k, I dont know why, I checked alot of things and its all ok.

Biss screw I cant move at all.

 

[KGB Pilot125]

well turns out I was right in one of my theories. the throttle blades were being held open at idle causing a high idle. Today when I got home I sprayed the spring on the TB with WD-40 and messed with it a little and noticed how tight it was. I loosened up the 2 bolts on the intake mani and slid it to the passenger side and started it up idled at 1000 until it warmed up and then dropped to 800-900 RPM. There is still some problems with the idle like a bad miss and some hacked wiring at the TB also the BISS has no effect on idle still but at least its not at 2000 RPM anymore. I have quite a bit more work to do just have to get more time.

Josh