Idle Questions

[PhillyD]

Hi guys:

I'm looking forward to getting my car ... maybe in hand sometime next week?

When I test drove the car it was really smooth running and powerful but I had a question about the idle. When it was cold and started it was like 1,000 but after a mile or so it went down to 600-700 at stop (with foot on brake.) It would take a second or two for it to get down from 1,000 once stopping but it did so fairly quickly. It's a 9,200 mile car with documentation to the miles over the years and am wondering if not running alot would mean I should tune it up?

How should these cars idle at cold start, cold stop, warm start, and warm stop? Since there's no carbs how do you adjust for idle anyhow on these things.

The learning process begins! LOL Thanks for all your help.

Phil

 

[TURBO1]

Mine does that too, I think alot of them do. To adjust the idle, you will need a scantool & follow the air rate adjusting procedure using the IAC & TPS. Just make sure the throttle body is clean of all carbon deposits & vehicle needs to be at operating temp, in closed loop. Heres a link to the procedure.

http://89tta.turbobuicks.net/airrate.htm

I think theres another way also, but I can't find the link right now, I'll post later if I find it or if some one else can jump in too :detective:

 

[PhillyD]

Thanks Turbo! That was a neat read ... I've got alot to learn about these terms and procedures. I just learned how to tune up my Goat and now this is a whole different ball of wax.

 

[WS6]

You can set basic idle characteristics but the ECM controls idle speed based on the chip's program.

It uses the IAC valve( stepper motor with pintle valve) to do so,along with the O2 and other sensors. Your life will be a whole easier with a scanmaster,especially with idle issues.

Baby steps though...get the car in your driveway and we can go from there.

 

[El Dee Bee]

Mine does that too, I think alot of them do. To adjust the idle, you will need a scantool & follow the air rate adjusting procedure using the IAC & TPS. Just make sure the throttle body is clean of all carbon deposits & vehicle needs to be at operating temp, in closed loop. Heres a link to the procedure.

http://89tta.turbobuicks.net/airrate.htm

I think theres another way also, but I can't find the link right now, I'll post later if I find it or if some one else can jump in too :detective:

I know that the correct official way, but I just turn the screw on the throttle and it raises the idle right now. I raise it to ~ 1100 RPM everytime I go for SMOG. testing. I'm pretty sure it lowers the HC @ idle.

I think the inital high idle is because of the warm up cycle. It keeps the idle higher for a few minutes until the engine warms up, like the old thermostatic chokes on a carburetor.

 

[V6TA-MI]

Phil
Call when you get the car and we can take a look at it.

Glenn