Need help solving a missfire problem
 

Background:

1 - Car has been running fine, but has some idle issues on cold start. Needs a re-tune/adjustment for the cams.

2 - Took car to car wash about two weeks ago. When I got home, I found some organge fluid under car. Same color as my coolant. I tested it with pH strips and the coolant and the orange fluid were very different. Thought it might have been the degreaser from the bottom spray.

3 - Few days ago car started with a bad miss. Misses badly under load when cold. Gets better when hot. Goes to WOT fine. Misses when cruising under light load.

4 - Pulled 7 of the 8 cops (can't get the last one out). OHM tested the 7. All read the same and showed no short. Is this an effective way to test a COP? I can see how this would find a short, but perhaps not a different type of problem.

8 - Found the plug hole full of fluid on the passenger side near the fire wall. There was about 1 to 2" of fluid in the plug hole. Fluid looks just like the orange fluid I found dripping from the car after the car wash. Could either be car wash cleaner or coolant. I am going with coolant. What would cause coolant to burp out from a car wash?

9 - The COP coil on this flooded one was clean as a whistle. If it was rusty water in the plug hole the coil would be rusty. I think the coolant would prevent it from rusting. Makes me think it was coolant.

10 - I dried it up...started car back up....still runs shitty as before.

Any ideas?

Next steps:

1 - Pull last COP.

2 - Pressure test cooling system to look for leaks.

3 - Pull all plugs and inspect.

4 - Compression test each cyclinder.

5 - Replace suspected bad COP with good one and see how it runs.


I have friend/mechanic coming over this week. He installed the motor for me. Bad COP....no big deal. Leaking coolant....no big deal. BUT, if I somehow have a bad cyclinder doing this, I will be pissed. HOWEVER, not sure how a bad cyclinder would make car missfire, but pull normal and hard under WOT.

Makes me suspect electrical problem caused by water/coolant being where it is not supposed to be.

Any thoughts?

I got the back plug out (one with the flooded plug hole) and it was a bitch to remove. Plug looks fine, but tons of grit in the threads. I hope it is not cross threaded. I think as i was pulling it out, grit was getting on the threads and it made it hard to to remove.

I need to see if I can some how clean out the hole before re-installing. I may try and get a new boot for the COP in case that thing is dicked-up.

the orange goop is probably the ticket to the answer.

Get yourself a can of compressed air and blow that down in there to clear out any debree

or any debris:D

I don't want to blow the crap into the cylinder. I am going to use a thread chaser and have a friend with a computer that is going to hook it up to try and pin-point the miss.

I am gonna go with bad COP. Have you ever replaced them all? You can get full sets on Ebay new for in the $120 shipped rang. These things don't like to get wet all the time. I replaced mine a few years ago and think I need to do it again.