stangbnmalo

Hey guys: I had the code P0320 coming up, I replaced the iac valve and gasket, but the car still won't start. It first started to have a rough idle and it would die unless you gave it some gas, but now it won't even start.

Z28KLR

Did you reset the ECU? If not it's probably retained memory and still thinks the problem exists. Reset it with a diagnostic tool or you can disconnect the battery for like 10 minutes to do it as well, I think. If you've already tried one or both of those, then open a beer and wait for someone else who knows more than me to reply.

StripeyGT

Are you sure you fixed the right thing? My SCT manual says:

P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction

Seems like you have an ignition related issue.

cliffyk

^+1, here's what the shop manual says about P0320.

Nothing to do with the IAC--check the plug wires and coil packs for arcing...

Mustang Susan

The check engine code on my 1999 35th edition Mustang come up off and on going on 9 months now. I have done numerous repairs (O2 sensor, crankshaft sensor, camshaft sensor, new computer/flashed the keys, gas filter, gas pump inside gas tank, gas seal, etc.) all of this to no avail. The car coughs and sputters, jumps and leaps and does not have enough "steam" to get up over a hill. Other times it cranks just fine and I can drive around like "normal" for weeks at a time. What the heck do I need to do to fix this once and for all? I am at a loss right now . . .