Crazy idle almost tuned
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Crazy idle almost tuned
I'm close to properly tune my lt1 1995 idle.
At this moment idle at 900 rmp, if car is stopped in neutral (man trans),
Obtained by idle regulation screw on TB
The Only one issue remain is on running
As instance: go 3rd engine 900 rpm, step on clutch and go neutral for a while idle doesn't come back to 900 rpm, but stay up, about 1100-1200 rpm,
Until car is stopped Again, then slowly come back to 900 rpm
Any idea? Seems like to be something related to the speed.
ASR cable, speed sensor on transmission?
Already check for vacuum leaks seems not to be, even since that if idle works properly with car stopped should works properly on run too.
At this moment idle at 900 rmp, if car is stopped in neutral (man trans),
Obtained by idle regulation screw on TB
The Only one issue remain is on running
As instance: go 3rd engine 900 rpm, step on clutch and go neutral for a while idle doesn't come back to 900 rpm, but stay up, about 1100-1200 rpm,
Until car is stopped Again, then slowly come back to 900 rpm
Any idea? Seems like to be something related to the speed.
ASR cable, speed sensor on transmission?
Already check for vacuum leaks seems not to be, even since that if idle works properly with car stopped should works properly on run too.
Last edited by Christi@n; Jan 28, 2015 at 08:04 PM.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Could you explain me the proper idle reset procedure for 1995 lt1 corvette
Safety Car
Joined: Sep 2001
Posts: 4,137
Likes: 531
From: Glenbeulah Wi
I've almost succeeded to properly tune my lt1 1995 idle.
At this moment idle at 900 rmp, if car is stopped in neutral (man trans),
Obtained by idle regulation screw on TB
The Only one issue remain is on running
As instance: go 3rd engine 900 rpm, step on clutch and go neutral for a while idle doesn't come back to 900 rpm, but stay up, about 1100-1200 rpm,
Until car is stopped Again, then slowly come back to 900 rpm
Any idea? Seems like to be something related to the speed.
ASR cable, speed sensor on transmission?
Already check for vacuum leaks seems not to be, even since that if idle works properly with car stopped should works properly on run too.
At this moment idle at 900 rmp, if car is stopped in neutral (man trans),
Obtained by idle regulation screw on TB
The Only one issue remain is on running
As instance: go 3rd engine 900 rpm, step on clutch and go neutral for a while idle doesn't come back to 900 rpm, but stay up, about 1100-1200 rpm,
Until car is stopped Again, then slowly come back to 900 rpm
Any idea? Seems like to be something related to the speed.
ASR cable, speed sensor on transmission?
Already check for vacuum leaks seems not to be, even since that if idle works properly with car stopped should works properly on run too.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Go to the scalers and look for an IAC adder that is based on mph typically there will be an adder that raises the iac count the faster you go, when you stop the iac adder will decay away. Use a scanner to set your base idle speed if you want a 900 RPM idle warm you would like to see a iac count of 10 to 20 when the car is warm and stopped. (Adjust the idle screw to achieve this result)
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Go 1st 2nd 6th any speed you want, then engage neutral, don't allow to the car to stop it and idle stay high 1200 rpm, when I stop car idle slowly come back to 900 rpm
Yes i've manual trans
Racer
Joined: Jun 2010
Posts: 365
Likes: 27
From: Shelby Township Michigan
I've had a failure with my TPS and it caused a high idle condition. Luckily, I had an old throttle body with an old TPS and was able to compare the two. Something you may want to consider.
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Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Thanks, I will check it with multimeter, should it works to discover any malfunctions?
Safety Car
Joined: Sep 2001
Posts: 4,137
Likes: 531
From: Glenbeulah Wi
What program for tuning are you using? Typically you have flags (On/off changes), then you have (Scalers or constants which are 2d tables or changes) and then you have tables which are 3d tables. The IAC offset per speed of car is usually under scalers.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
Two links welll explained on how to check tps, i've found out...
http://www.enduringautomotive.com/tps/
http://www.enduringautomotive.com/ho...robe-a-sensor/
http://www.enduringautomotive.com/tps/
http://www.enduringautomotive.com/ho...robe-a-sensor/
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
I've tested with multimeter TPS both wiring and TPS sensor
Well First wiring its ok
Ground Black Wire 11.58V
Blu Wire 0.5V
Grey Wire 5V
Then with multimeter set on ohm scale
With TPS to 0 read was 6.60 K ohm, rotating TB shaft any difference appear in dispay, so any change in TPS resistance, I would assume that this is a BAD TPS sympthom
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
positive multimeter wire to the TPS plug where grey wire is,
during test TPS wasn't connect as above mentioned, just connect with TB shaft
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
There is your problem. Black is ground, grey is 5V+, and blue is the signal to the computer. Reading the ohms from black to grey will not vary with the change in throttle position.
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy
I will re check tomorrow...
Last edited by Christi@n; Jan 28, 2015 at 08:06 PM.
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
Thread Starter
Drifting
Joined: Sep 2014
Posts: 1,579
Likes: 59
From: Trieste Italy