[Diy_efi] 94-95 5.0 Mustang and a hanging idle...

[Keith Varin]

Hey everyone. First I would like to thank you all for viewing this thread.

I have a 1994 Ford Mustang Cobra with the 5.0 GT-40 motor and a manual
transmission. It is still relativly stock however with a few small mods I
began to have a hanging idle. After installing a new TB and headers the idle
would hang around 1800 rpms. my first thought was that i probably had a leak
in the intake tract somewhere. So i disassembled the intake and resealed
everything with rtv and high-tack gasket sealer. The problem went away, so I
figured I had fixed it.Low and behold, 3 days later it was raining out and I
began my 17 mile trip to work. Halfway there I realized that my car was
still idling around 1800rpms, so the work I had done did not fix the
problem.

I have since paid close attention to the conditions of the environment and
of my vehicle when the idle stays high, here is what I have figured out.

When moving at any speed greater than 15mph with the vehicle in neutral or
with the clutch pressed, the car will idle at or around 1100 rpms, and when
the vehicle comes to a stop it will idle at 800-900 (which is normal).
However, any time it is raining or very damn outside the car will idle at
1800rpms at any speed 15mph or greater with the vehicle in neutral or with
the clutch pressed.

If anyone has any input on why my car might be doing this or any ideas on
ways to fix this problem. please feel free to shout it out.

Thanks
Keith