vudoodoodoo

I took off all the emissions stuff and the air pump installed BOPs this weekend. Before that, my car start fine and ran fine. It would rev to like 1500 when cold and drops as the car warms up. When it's warm, it would start at like 1000 and drop back down to around 700-800 idle.
My idle was weird after doing all that stuff. It would rev up to 1500 when I start it cold. And it keeps goes up as the car warms up and idle around 1600.
I start checking around and found the fast idle cam. It's below and to the left of the Idle Speed Controller.
I would push this thing down and the idle would drop from 1600 to 700 or so. When I let go, it goes back to 1600. There is a screw on it that holds at a certain position. So, I take off the UIM and tightened that screw. Now the spring or whatever is in a certain position that is a little higher than before. Now the car would start all weird. Sorta lumpy and around 500 RPM. Then it would go to like 800 RPM when warmed up.
I'm happy that it idles normal when warm, but I don't like how it's so low when I start it up.
Anyone know what's the deal w/ this? I've read the the fast idle cam works with the throttle body coolant. It detects the temperature and adjusts the idle. If it's cold, the idle would be higher. If it's warmed up the idle would be 700-800 RPM.
I'm stumped.

vudoodoodoo

http://www.rx7turboturbo.com/robrobi...dy_coolant.htm

Rob Robinette site said that you would get a lumpy idle if you remove the throttle body coolant and wire open the fast idle cam. I seem to be experiencing the same thing. I didn't do this mod though. Hmm...
Maybe I should just do the mod anyways since I am experiencing the affects of it.

FDjunkie

I've found that the fast idle cam constantly adjusts the idle RPM based on the engine's coolant temperature. And while the effect is greatest at cold temperatures, it's still there even at normal operating temperatures.

If you remove the cam/linkage/throttle body coolant lines, or adjust them so that this system no longer operates, your idle speed will finally be controlled by the brass air bypass screw in the throttle body. However, disabling the idle cam sytem usually results in the poor cold idle performance that you've already experienced; a real pain for a daily driver or in cold environments.

The factory manual hints at all of this where it shows both a temperature adjsutment and a RPM adjustment for the fast idle cam. The shape of the cam profile and the response rate of the wax rod both also impact the resulting idle RPM vs temperture behavior.

vudoodoodoo

I have a PFC BTW. If that matters.

duboisr

My mechanic has removed the hot wax rod and the cam plates ,screw and all . A brass bushing takes up the space and keeps the sleeve into the seal for the TPS . The idle is smooth and steady hot or cold . The car starts fine and will idle cold. Some times it will stall and needs a restart , not often. He is controlling with the Power FC .

0110-M-P

iTrader: (10)

I've said this before in other threads. But check your cruise control wire if you still have it. Cause the housing can get stuck outside the cruise mechanism thing near the fender wall.

vudoodoodoo

I don't have cruise.