TT Chip,Idle Adjustment?

[HighMileage]

It's my 2nd day with my new 60lb/tt alky chip combo. Gone is the light throttle skip/surge,the quirky/erratic warm-up process,etc. Driveability is improved 100%. The best improvement I've made so far.

The only thing that I'd like to change is the idle rpm. It was 700-750rpm. Now it is 800-825rpm.

I notice on the PowerLogger that the Prog Idle is 838. It was 750 with the stock chip.

1)My TPS is at 40.
2)That screw on the other side of the throttle body is backed out to where it is not toughing the linkage.
3)IAC is at 38cts. 180'F.

No vac leaks.

Not sure where to go from here.


Should I just leave it where it is? It's just that I'm more on the brakes when coming to a stop. Plus,it goes into gear with a bang.

Steve. '87 GN. Mostly stock except for what is mentioned above,and an Accufab reg.

 

[TurboDave]

It's my 2nd day with my new 60lb/tt alky chip combo. Gone is the light throttle skip/surge,the quirky/erratic warm-up process,etc. Driveability is improved 100%. The best improvement I've made so far.

The only thing that I'd like to change is the idle rpm. It was 700-750rpm. Now it is 800-825rpm.

I notice on the PowerLogger that the Prog Idle is 838. It was 750 with the stock chip.

1)My TPS is at 40.
2)That screw on the other side of the throttle body is backed out to where it is not toughing the linkage.
3)IAC is at 38cts. 180'F.

No vac leaks.

Not sure where to go from here.


Should I just leave it where it is? It's just that I'm more on the brakes when coming to a stop. Plus,it goes into gear with a bang.

Steve. '87 GN. Mostly stock except for what is mentioned above,and an Accufab reg.

There are no provisions for mechanical adjustment of idle speed. It's all chip controlled.

The IAC adjustment screw reaslly shouldn't be backed out that far. It should be touching to just more than touching. You're IAC at 38 is very good, but could be better. Bringing the IAC screw into the point of touching and then another 1/2-3/4 turn will likely bring the IAC down into the 20's.

And of course the TPS will have to be readjusted to show .40-.42l


All of this won't adjust your idle speed but it will get the IAC and TPS in perfect range.

 

[Eric Stage I]

Yes, Dave is correct.

On the idle speed, I've found 800-825rpm is good for those injectors for a decent idle and good off-idle response. I can lower it if you want, but I can't guarantee the idle/off-idle performance.

 

[HighMileage]

I finally found some time to try and get my #'s right.
No matter what,IAC won't go into the 20's,not even low 30's. The more I turn the screw to push the linkage,the higher the IAC # goes. Meanwhile adjusting the TPS to stay at .40-.42.

Right now the IAC is at 54 with the screw a 1/2 turn into the linkage. TPS .42.

Coolant temp 180'F. No accessories on. Idle rpm 850.

Steve. '87 GN. PowerLogger,60lb inj,tt alky chip,Accufab reg.

 

[TurboDave]

I finally found some time to try and get my #'s right.
No matter what,IAC won't go into the 20's,not even low 30's. The more I turn the screw to push the linkage,the higher the IAC # goes. Meanwhile adjusting the TPS to stay at .40-.42.

Right now the IAC is at 54 with the screw a 1/2 turn into the linkage. TPS .42.

Coolant temp 180'F. No accessories on. Idle rpm 850.

Steve. '87 GN. PowerLogger,60lb inj,tt alky chip,Accufab reg.

A good rule of thumb for the minimum air bleed screw (the one you're messing with), is as follows:

See where the tip of the screw comes through the mount and touches the throttle mechanism?? You should be able to see 1 to 2 threads showing through on that side.

 

[HighMileage]

A good rule of thumb for the minimum air bleed screw (the one you're messing with), is as follows:

See where the tip of the screw comes through the mount and touches the throttle mechanism?? You should be able to see 1 to 2 threads showing through on that side.

I see about 1 1/2 threads.

Could the high IAC number mean that the IAC needs to be cleaned or is not functioning properly? I doubt it has been out during the car's 82,000mi.

The car is going up on blocks soon for body bushings,hot-wire,etc at the first sign of road salt. All of that will probably take me awhile. But I'd like to get to the bottom of these high IAC #'s.

Thank you for your input.

Steve. '87 GN. PowerLogger,60#,tt alky chip,Accufab reg.

 

[norbs]

I can,t see your iac numbers going up as you increase the screw do a log and re check. Yor not turning the screw enough. reset power to the ecm it will have to reset its position.

 

[HighMileage]

I can,t see your iac numbers going up as you increase the screw do a log and re check. Yor not turning the screw enough. reset power to the ecm it will have to reset its position.

I did just that,actually twice. Now things seem to be getting more normal.

Before,I'd turn the screw,the idle climbed and the #'s went up. Thats not supposed to happen. Not anymore.

I checked it again last night after driving around town running errands. ...

RPM: 825-850.
TPS: .40-.42 while running. I must have it set at .41.
IAC: 28cts

One thing with this t-t chip that I did notice... All of my cells are +/- 5 of the acceptable 128. With the stock chip,they were all over the place.

The exception is the idle cell which is 142.

Thanks for your patience and suggestions.

Steve. '87 GN,t-tops. PowerLogger,60#,tt alky chip,Accufab reg.

 

[Eric Stage I]

A high idle BLM is typically caused by either a vacuum leak, or a bad MAF. Other causes can be a bad O2 sensor, or cracks in the exhaust headers.

 

[norbs]

What kind of maf/translator is on the car?

 

[HighMileage]

What kind of maf/translator is on the car?

I've got a reman MAF from Cardone that's about 1 month old. I also have the stock MAF. They both are near 5 g/s at 825 rpm idle. Tonight,the Cardone was 4.7 g/s. Both survive the tap test.

Tonight I noticed that my O2 sensor is counting very slowly,becoming stuck at 111 for 5 minutes. It's a Denso.

But hey,the IAC is now at 5 cts thanks to 2 more turns of the screw. Seems like alot of turns. TPS is reset at .42.

The idle cell is down to 137. The car has that new car exhaust smell and drips water out of both pipes. From what I've heard,water is a sign of complete combustion. I could balance a quarter on the plenum at idle.

It seems like time is straightening things out.

Steve. '87 GN,t-tops. PowerLogger,60#,tt alky chip,accufab reg