89 Vette Idle Speed
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Joined: Jun 2007
Posts: 64
Likes: 0
From: Binghamton NY
89 Vette Idle Speed
After having a remanufactured 350 installed in the beast, she is idling high at 800 rpm.
I have read that the ideal idle speed is around 500 to 550 rpm.
Also have read (in the manual) that the idle speed is not adjustable.
Does anyone have any insight into the idle delimma?
Thanks
I have read that the ideal idle speed is around 500 to 550 rpm.
Also have read (in the manual) that the idle speed is not adjustable.
Does anyone have any insight into the idle delimma?
Thanks
Racer
Joined: May 2006
Posts: 426
Likes: 16
From: Concord CA
The Min Low Idle is adjustable. Follow the FSM on the correct prodcure. You might have to remove the plug to get to the low idle screw in the throttle body.
Once you have set min low idel, setting the correct TPS setting (.54v).
If that doesn't correct the high idle, I would start checking Other things: bad gaskets for the intake, vacuum leaks (hose and lines), sticking throttle, Fuel Pressure/Regualtor settings, Bad IAC valve, TPS settings.
Has the reman 350 been modified as compared to stock (CAM)?
Once you have set min low idel, setting the correct TPS setting (.54v).
If that doesn't correct the high idle, I would start checking Other things: bad gaskets for the intake, vacuum leaks (hose and lines), sticking throttle, Fuel Pressure/Regualtor settings, Bad IAC valve, TPS settings.
Has the reman 350 been modified as compared to stock (CAM)?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Idle speed is controlled by the ECM based on Coolant Temp, Load and whatever is burnt into the Chip or Prom. Actual Idle Specs are +/- 50 RPMS from ECM Targeted Idle Speed in Drive; +/- 100 RPMS from Targeted in Park/Neutral. There are no adjustments short of reprogramming. To see what yours is doing, you need to scan it. Monkeying around with anything without knowing can lead to trouble.
Safety Car
Joined: Sep 2003
Posts: 3,599
Likes: 24
From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Idle speed is controlled by the ECM based on Coolant Temp, Load and whatever is burnt into the Chip or Prom. Actual Idle Specs are +/- 50 RPMS from ECM Targeted Idle Speed in Drive; +/- 100 RPMS from Targeted in Park/Neutral. There are no adjustments short of reprogramming. To see what yours is doing, you need to scan it. Monkeying around with anything without knowing can lead to trouble.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
Check to make sure your Throttle body isn't dirty and hanging up, use cleaner and if that doesn't work pull it off and check and clean the IAC and air channel . Than check you TBS and make sure its set correctly. I would check these things first before I started changing and adjusting things. When my 89 had a fast idle it turned out to be the throttle body was all gummed up.
