I need to turn my idle up, Its a 87 305 TPI, the idle is low and sometimes when initally shift from park to R of D it sounds like it wants to die...Help fast
thanks

 

Adjusting the idle has a few steps involved in it. First, u need to ground the ALDL connector like you're going to check it for codes. Turn ignition on, wait 30 sec. After 30 sec, with that terminal still grounded and ignition ON, disconnect IAC electrical connector.

Turn ignition off, and remove whatever you used to ground the ALDL. Start car. The SES light WILL GO ON AND STAY ON because the IAC is not connected. On the side of the throttle body where the throttle linkage is, there will be a small hole with a Torx screw inside. Have a buddy put the car in DRIVE and press the brake and hold it. Adjust the idle screw in or out so that the car idles at around 450-550 RPM in DRIVE. After that is done, put car in PARK and shut off engine.

Now, get a digital voltmeter, and use the metal ends of the probes to check the top and middle terminal of the TPS. You just stick the metal tips into the connector; I never disconnect it and jump it. If need be, loosen the two side screws and adjust the TPS up and down until the voltage is at about .54 to .56. Tighten screws and reconnect IAC.

Start car and the idle should be up a little more.


I'm pretty sure that is how idle adjustment is done, but do not take my word as gospel. If anyone has anything else to add, please do. I AM NOT RESPONSIBLE IF THIS METHOD DOES NOT WORK.

kev

 

Before you try to "cheat the system", I'd suggest just trying to reset the IAC, if that does not work for you, the pull the TB and clean'er up, as well as all the passages.

The idle rpm is set in the EPROM, yes you can fudge over it by adjusting the TB blades opening, but all you're doing is putting a bandaid on a continually bleeding issue...eventually you'll have to fix it correctly.