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I hate it when I'm right

but so far I was wrong, which is at least as distasteful.

Dreya's spark plugs look great. They're not the cause of the problem.

"What is the problem?" you may ask.
It has a cold misfire.
"The cause?"
Now that I've had only a cursory look I don't know for sure, but I suspect I won't like it.... not at all.
Symptoms suggest more diagnosis of the ignition system. I hope it pans out. My gut says something else. I hope I'm wrong.

Posted by Scott Korb on September 21, 2009 9:19 PM |

Comments

I'm not ASE trained, but my first reaction is that the computer is sending the wrong info to the fuel injectors and throttle during warm up causing the cold misfire.

Posted by: vern | September 22, 2009 10:43 AM

Throttle body injection and only drops one cylinder... #3

Now the misfire is more random than I thought. I couldn't test at all today because it wouldn't miss.

It missed just long enough yesterday to pin down which cylinder. I swapped the #3-#1 spark plugs today to see if the miss will follow.

Posted by: scott | September 22, 2009 9:58 PM

Bad wire going to #3?

Posted by: Vern | September 23, 2009 1:01 PM

I haven't ruled that out, but they are newish NGK wires.

I discovered today that this engine runs the PCV through a catch-can to the #3 cyl only. I'm hoping it's related to the problem. I still can't get it to fart again.

I drive differently than she, and maybe that old can is collecting/has collected enough tar-milk to need replacement. Or maybe I can just keep driving 20miles to work at high RPM and burn it out ;)

Either way it's better than a bad valve.

Posted by: scott | September 23, 2009 11:37 PM