I took my Civic through the car was yesterday and decided to rinse the salt and winter funk off the engine and out of the engine compartment. It ran fine afterwards but later started idling at 2k. It started idling normal then back up and down. Now its idling high, the check engine light is on and it wont take fuel, it sounds fine and isn’t missing though so I don’t think its ignition or spark related. Any ideas? Im going to borrow a friends code reader tomorrow and see what code its throwing but thought Id see if anyone knows of a sensor or wiring harness that could be wet. Thanks again, Matt

 

i would leave the hood open in the sun for a day to let any moisture dry out, should clear up the problems.

 

did you get the code?

 

Check your sensors and make sure you didn't damage any of them and they didn't retain some water/moisture.

 

^ X2!!! Water and electrical components dont get along, you have to be careful when washing under the hood, i always always always cover my dizzy, plug wires and harness connections with reynolds wrap before washing mine...it takes longer but doesnt yield the results you are having.

 

I've seen water work its way into the spark plug tubes and cause erratic and no start problems after an engine bay wash.

 

Turned out it was the vacuum line for the cruse cracked and was sucking air! A new piece of rubber hose later and my car was back to 100%!