I have a cylinder misfire on my 3.8L 94' mustang. Computer identified it as cylinder 2. I pulled the plug and the center post was blown completely off (missing anyway, might be defect.) While I was pulling out the plug I noticed that the boot was not even on the plug.

I replaced the plug and the problem improved, but it's still not back to normal. Should I just drive it a little and run a higher test for maybe 20 miles to flush it out (the plug was almost black from where something was obviously burning (oil?)). I've seen some mixed things that running it with a boot popped off can destroy the distributor.

Help would be lovely, I'm about to the end of my knowledge and budget.

4/16/2007 9:53:25 PM

Yeah what do you mean it is not back to normal?

4/16/2007 10:14:57 PM

was that the only plug you replaced? Try changing all of the plugs and wires.

4/16/2007 10:37:59 PM

I just put all new Bosch Platinum 2's in about 4 months ago. I tested the wire with a generic set I had lying around. When I hooked it back up it ran much smoother (like it was working better) but there was still much more vibration that normal. I'm heading to the auto store to get the computer reset and see if it trips cylinder 2 again. Thanks for the help.

4/17/2007 12:14:45 AM

They wont reset it, pull the negative off for about 20 min.

4/17/2007 11:57:02 AM

They reset mine at advance since it still had the misfire codes from before I changed my plugs and wires.

4/17/2007 12:30:04 PM

they reset it... have replaced wires & plugs. still has misfire on #2

my car uses a coil type distributor - is there some way to test these without having to just replace it and see if it helps? I mean, it could be fuel injector or anything...

4/17/2007 1:43:23 PM

They sell these wire testers at advance that you can use to test spark plug wires. You ground one end, stick it in a plug wire and start the engine.

4/17/2007 3:40:23 PM

I've replaced the distributor, wires and plugs. Still not running right. what next?

4/17/2007 4:52:17 PM

check the compression

4/17/2007 5:14:30 PM

first, you shouldnt be using bosch plugs, and certianly not +2s, they suck, and wether you want to waste your money on platinium is your choice. get some standard autolite or champion copper plugs.

second, when you pulled that original plug and the center electrode was blown away, the next thing into that hole should have been a compression tester. usually large chunks of a plug missing indicates mechanical damage, if not the cause of the damage to the plug, the stray peice could have managed to be pinched in the exhaust valve seat, damaging it and hence the misfire you cant seem to cure.

get a compression test done, or do it yourself. pull all the plugs and disable the ignition system and/or fuel pump (pull fuse/relay). the rest is fairly easy, you install the compression guage and spin the engine over until the reading stops climbing, no single cylinder should vary by more than 20% from any other.

those engines suck, there is no telling whats happened.

4/17/2007 6:01:34 PM

compression test - will report back when i have results thx tww

4/18/2007 4:14:24 PM