I am stumped. I have a 1991 Civic DX converted to MPFI w/ D15 engine.

I am getting a code 14 which is the IACV. I have cleaned the IACV and also replaced it. I can also hear the valve opening and closing via a metal rod when the engine is running. The car does not idle, it just dies. To bypass this I have set the throttle cable to hold the throttle body open very slightly to idle. What can be causing the IACV to not work properly?

The second problem is the hesitation. When the car is in open loop(cold) it runs perfect minus the idle problem. As soon as it hits closed loop(warm) I get a horrible hesitation from idle to about 3000rpm. So this, for the most part, rules out ignition/fuel problems and timing, it has to be a sensor but I am not getting any codes other than IACV(14). I also get a small sputter right around 5000rpm.


Steps I have taken so far...
Cleaned IACV
Replaced IACV
Replaced O2 sensor
Replaced PVC
Replaced rotor button
Replaced distributor cap
Replaced plug wires


What is wrong?

Thanks, Nick