local311

I have a 2005 GT conv with 43000+ miles. When I am coming to a stop and push the clutch in the idle drops to normal (600 -700 rpms). Without touching the accelerator the idle goes up to 1000 rpmsfor a second or two and then falls back down to normal. Sometime this repeats itself a few times. Any ideas.

Thanks ,
Ken

howarmat

is the air on?

local311

It does not matter. It does it whenAC is on or off. I will monitor to see if it acts differently.

Thanks,
Ken

157dB

Is the DEFROST on.
Far right **** turned fully clockwise as far as it will go.
That runs the A/C compressor also without turning on the A/C indicator LED.
Have you done the gas pedal mod?

GT Bob

It's nothing that complicated actually guys....

When your clutch is out, even with no gas, the engine is still under a slight load, so the computer will be giving it a small amount of extra fuel above whats required to idle unloaded. Push in the clutch, and suddenly the engine is unloaded. It takes the car a second or catch up to the fact that its now not loaded and use up the sprayed fuel. Since it has the fuel for the extra work already there, it uses it up in the form of a slight spike in rpm's.

local311

I bought the car new and this just started. Even if I continue to hold the clutch in with no pressure on the accelerator it will rise more than once.

Ken

local311

After driving the car for the last few days it appears that the A/C does effect this problem. With the A/C off it is not as pronounced and barely noticable. With it on it revs 300 to 500 RPMs up and down.

MustangGT0405

Try cleaning your MAF sensor.

They can get dirty and cause all sorts of weirdness, escpecially RPM spikes.

Fullsayl

OK, I am gonna regret this...but do you have an aftermarket TB installed?

~Matt