Misfire Cyl 3 after wash.

[stevet47]

I have a misfire in cyl 3 (code p0303) that started after I washed the engine of the ranger. It is my wife's ranger and this was the first time I have ever washed it. I have washed the engine in all my other vehicles without a problem, but apparently the ranger doesn't like to get wet.

It is a 2003 with the 3.0L.

I pulled all the plugs and they looked good. I cleaned the terminals, hit them with WD40 to get rid of any water, and put some dielectric grease in both boots on all the plug wires.

My question is... knowing this started right after a wash, what do you think the most obvious problem would be? Or how to I check a few things to figure out what it is?

thanks!

 

[Earl43P]

I'd start with the plug wires.

Either buy new ones or swap the #3 wire with another of equal length and see if the misfire follows the plug wire or stays on that cylinder #3.

Clean the wires with some Simple Green or similar degreaser (not a solvent!).

 

[kwtorbe]

I had the same problem and code after washing my 2.3L DOHC. It ended up being the MAP sensor...and I never got a code indicating that the sensor was flatlined. Thank God my brother is a mechanic with a handy-dandy Ethos!