LSCHLEM

When coming to a stop sign the rpm's drop from throwing it out of gear.
the rpms drop to about 300 then recovers to the 850 which is what I have
the idle set to. I have had this problem for some time now and i missed
taking care of it during my last tune up with the H&C. Its overshoot to
idle. I'm planning on getting a COW Booster soon and I want to take care of this problem prior to installing the Booster.
I was talking to Joe G a time ago and he was looking into the DECEL part
of the tune. If anyone had this problem and found the fix please give me some input. BTW I have HP TUNERS but did very little in the way of tuning the Car myself . I know how to use it Thanks, Leon

gbrtng

torque convertor not unlocking?

Gering

My GF's Camaro acted like that and the problem was the MAF sensor.

Zip Corvettes

It needs more idle air.

Joe_G

Add 5% base running airflow in the idle area and see how that does. If too much it will cause idle to be too high or have cruise control. You can fine tune it and dial it in.

You will love the Cow Booster, I guarantee it.

By the way my daily driver Prius has a cow booster from the factory, an Eco and Pwr button which remaps the throttle like the cow booster.

LSCHLEM

I will try running more idle air and see what happens. Another way it acts
is that it is fine when the engine is cold and becomes more prevalent when
the engine is hot and I'm coming to a stop. If I am stopped and I rev the engine to say 4000 RPm then take my foot off the pedal it will gulide down to the 850 rpm without any hicups. thanks guys for the help.

Joe_G

That's common, when the car is cold specified idle is usually 1000 or so.

Probably more common to have the problem with the AC on as well...that puts a load on the engine. You can jimmy around with the AC load but you probably won't need to.

LSCHLEM

Yep, a 5% increase in "Min Air Flow" did it. I drove the Car around for a few miles and it's behaving like it should. I guess one could go too far in adjusting the tables and probably another 5% and I would have cruise control. Thanks again guys, Leon

Joe_G

Thanks for the nice sentiment Leon!

Yep, too much and you get cruise control or an idle that is higher than you command. Matter of fact I command 750 but after putting on my AFR heads I get 850 but I'm too lazy to fool with it as the car runs great!

Chuckc-3

How does one adjust idle air on a '90? Must I change the MAP censer?

LSCHLEM

The problem with stalling at a stop is more prevalent than ever. Replaced the MAF altogether and that made no difference. I finally got my mpv1 working and going to add idle air but before I do that I will check the throttle Body. Hope something works.

LSCHLEM

OH MY. I lived with this problem for a couple of years now. I just read that the THROTTLE BODY around the butterfly should be checked. I never looked until now and It was all black and gummed up around the butterfly. A little carb cleaner and a micro towel and PROBLEM solved. The car drives real nice when pulling out and never drops below 800 RPM where the idle is set. The way it feels now I can pull out with just the clutch and it moves out.

vt65

strange it didn't throw a code for the throttle sensor