Misfiring but don't know why

[dolezal83]

Hey everyone, I have a 1994 SR5 4Runner (4X4) 3.0 V6 and recently I used some degreaser and washed it off with hose water (no extreme pressure) and now I can feel the car working off of only 5 cylinders. Sometimes the car run fine, i.e. all 6 cylinders, and sometimes the engine is only firing 5 of the cylinders.

Does anyone have any suggestions on what it could be ?

I checked the distributor cap and no visible signs of damage. I did this about 2 days ago.

Please help.

Thanks,

Joe

 

[jharris2]

Did you check the spark plug wires? Are they on tight and have no cracking?

I've also seen where a hairline fracture in the distributor cap is almost invisible, but enough to let in moisture to cause a misfire.

 

[dolezal83]

but wouldn't everything go back to normal after the water dried up becuase I took off the dis. cap and there was no water there.

 

[dolezal83]

but wouldn't everything go back to normal after the water dried up becuase I took off the dis. cap and there was no water there.

 

[ultrabongo]

Its usually the wires. They can look good and check out OK with an ohmeter and still be arcing to ground thru cracks you can't see. Try watching the wires with the engine running at night- sometime you can see the arc. Some mechanics mist the wires with water from a spray bottle and watch for arcs. The prior poster is right- a hairline crack in the cap will misfire erratically- the water you sprayed on just highlighted the problem.
Could also be a bad plug.

 

[jharris2]

but wouldn't everything go back to normal after the water dried up becuase I took off the dis. cap and there was no water there.

In my experience, not necessarily. It's possible that in washing the engine bay some moisture got somewhere it doesn't belong, and it hasn't left yet. It's also possible that as the engine cools, the moisture could condense again and continue causing a problem.

I'd triple-check the distributor and the spark plug wires.