I have a 87 vette with auto trans. When car is in motion, won't idle down below 1100-1300 rpm. When car stops moving, normal idle returns. T.V. cable seems to be adjusted properly, fluid level good. HELP PLEASE.:help:

At what speed will the idle return to normal? The ECM programming adds air via the IAC on deceleration for emissions reasons. With no more info, your "problem" sounds like normal operation.

RACE ON!!!

Are you saying the car goes down the road at 1300 rpm with your foot off the gas?

If you take car out of gear at any speed idle only goes down to 1100 to 1300, only when car is completey stoped it will idle down. So it is like the fast idle is stuck on unless you are stoped.

At what speed will the idle return to normal? The ECM programming adds air via the IAC on deceleration for emissions reasons. With no more info, your "problem" sounds like normal operation.

RACE ON!!!
I agree with CFI sound normal.
David

I don't understand why you're shifting an automatic into neutral while rolling down the road.

because of the problem of, soon as you start to move the idle goes up, I was just doing tests.

I agree with CFI sound normal.
David

I am sorry but the car never done it before, and a car should not go down the road by itself without your foot on the gas. "NOT NORMAL"

Are you saying the car goes down the road at 1300 rpm with your foot off the gas?

Yes unless you are lugging up a hill.

I am sorry but the car never done it before, and a car should not go down the road by itself without your foot on the gas. "NOT NORMAL"
Are you sure you know what normal is? What has changed since the car "never done it before" and the car do it now? That is a normal function. If there is a problem with how your car reacts, do some tests. I have a friend that disliked that "action" so much that eliminated it. When the car was warm and idling where he liked it, he unplugged the IACs (it was a Crossfire). Doing that will eliminate your cold idle and the adjustment of the idle speed to compensate for various accessory loads, but even if only temporarily, as a test, you can eliminate the ECM (or not) from the list of causes. If you don't like it, trouble shoot to find the cause and remedy it. Almost always an increase in idle speed is due to an increase in available air, vacuum leaks, etc. Off hand, especially with this being a programmed function, I can't think of any other reason for the air into the engine to increase with vehicle speed as you state.

RACE ON!!!

Sounds like you stumped the expert.:ownedbutton: :seeya:

Sounds like you stumped the expert.:ownedbutton: :seeya:
Do you mean you???

The guy that asks a question on one forum then plays the expert and answers the same question on another forum?

And he who also, when he asks a question, argues with the expert, well informed, well meaning responders?

RACE ON!!!

:ownedbutton: :2ni19wj:

:ownedbutton: :2ni19wj:

So what is new?

I don't believe I have seen even one of your posts that doesn't apply to.

RACE ON!!!

Lets start over with my problem. My car idles fine when it sits still. As soon as it goes about 5kms per hour, it jumps up to 1300 rpm on its own without ever touching the throttle. Only when car is stopped again will idle return to normal (650 rpms). This makes the car hard to stop or slow down with the motor pulling at 1300rpms. I have changed I.A.C. and T.P.S. lately. T.P.S set at .54 volts is this correct? Possibly a connection with these new parts? Thanks

Lets start over with my problem. My car idles fine when it sits still. As soon as it goes about 5kms per hour, it jumps up to 1300 rpm on its own without ever touching the throttle. Only when car is stopped again will idle return to normal (650 rpms). This makes the car hard to stop or slow down with the motor pulling at 1300rpms. I have changed I.A.C. and T.P.S. lately. T.P.S set at .54 volts is this correct? Possibly a connection with these new parts? Thanks
Throwing parts and money at it isn't the answer as this should have taught you. The TPS adjustment at 0.54 volts is correct for my car, I suspect yours too. What does your FSM say?

What did you learn from the tests I suggested? It is difficult to proceed when we don't what you have done and the results.

RACE ON!!!

One thing you mite check is the Cruse Control servo and cable. Maybe the vacuum lines are hooked up backwards? some thing to check.
David



Lets start over with my problem. My car idles fine when it sits still. As soon as it goes about 5kms per hour, it jumps up to 1300 rpm on its own without ever touching the throttle. Only when car is stopped again will idle return to normal (650 rpms). This makes the car hard to stop or slow down with the motor pulling at 1300rpms. I have changed I.A.C. and T.P.S. lately. T.P.S set at .54 volts is this correct? Possibly a connection with these new parts? Thanks

One thing you mite check is the Cruse Control servo and cable. Maybe the vacuum lines are hooked up backwards? some thing to check.
David

THANKS ALOT I WILL TRY THAT.