Engine Age Old Idle Question For Automatic

[Justin87]

Hello everybody!

I believe my 90 GT automatic is idling a bit low.



When I put it in gear the motor bogs down to around 450 RPMs, and the car feels like it wants to die for a split second.

I'm going to reset my idle. I know the procedure. (I've seen it posted here as well as the corral etc.)

My only questions are:

1. What should the base idle be set to? I've seen 750-800 for a 5/speed 900 for an auto. I have also seen 700 across the board. I am just looking for an better consensus. Car is stock.

2. For an automatic, do I set the idle in neutral or park?

Everything else I should be good on. It's been a while but I've done it many times before on my old GT 5/speed. I have a new IAC and TPS aswell.

 

[mikestang63]

it will depend on the engine
A stock build you are looking for around 700
The car should be in park

 

[Mustang5L5]

Set the base idle in park. Ignore the RPM in the dash. These things are notoriously inaccurate. Set the lowest stable idle you can without risk of stalling with IAC disconnected.

Clean the IAC as well, it may be gummed up and slow to respond