wpsrea

I have a problem with a rough idle when it is damp/heavy humidity out.
The idle will eventually smooth out as things dryout under the hood. I have changed the IAC motor but that didn't help. Any thoughts.

Randy93

Are you throwing any codes?

I live in the rainy state, AKA Florida and I read a post about people having your problem had opti issues. Also, humid weather and rain also help electricity conduct. Check plug wires, coolant temp wires and MAF plug for good connections, then check the opti last, as this is a real PITA.

flylowguy

check the plug wires first.

wpsrea

I replaced the opti last summer but did not do the wires. Also, once I crack the throttle the engine smooths out and runs as it should. Under acceleration there is hesitation, mis, etc. just strong acceleration. I was thinking the IAC is bad and effected by the weather. I also live in Florida and we have had rain all day. It has been idling crappy all day.

crheinish

Make sure the coil wire is on all the way. I would replace the wires.

Old182

My money would be on wires, too. I watched a dealership spray water on secondary wires from a spray bottle while the engine was at idle to determine whether they were good or bad - worked like a charm. If your wires need replacement, the engine will stop. My $0.02.