Who knows about ignition

**Spikito** · 10-31-2008, 08:59 PM

ok so you might have seen my recent thread about torque converter shutter. so i got my tranny and TC flushed, didnt help my problem. so they hooked up the ODBII and pulled up this screen that was watching my spark plugs. particularly whether they fired or not.

he put my car in reverse, step on the brake and ran it up to about the 2500, the car starts shaking and sputtering, and cylinder 6 starts showing a shitload of misfires. 42 in a couple of seconds. but at idle its fine.

I'm thinking a wire got against a pipe when i changed my plugs a month ago, but it only misfires under load, when im driving it does it if i really step on it, or if im going up a hill, anyone got suggestions?

**jigger1166** · 11-01-2008, 04:10 AM

It could be the plug wire, or a crack in the porcelin of the spark plug, or the ign. coil.

The way to find out is to first, swap the wire with another cylinder, and recheck the misfires. If it moved with the wire, it's the wire. If not, swap the plug with another cylinder and recheck the misfire, if it moved to that cyl. it's the plug. And if the misfire's still at #6, swap the ignition coil with another cyl.

Good luck

**spike669** · 11-01-2008, 04:14 AM

If your car is a 3.8 check the wires.Also check the posts of the coils for rust or corrosion.

**Spikito** · 11-01-2008, 02:27 PM

Originally Posted by jigger1166

It could be the plug wire, or a crack in the porcelin of the spark plug, or the ign. coil.

The way to find out is to first, swap the wire with another cylinder, and recheck the misfires. If it moved with the wire, it's the wire. If not, swap the plug with another cylinder and recheck the misfire, if it moved to that cyl. it's the plug. And if the misfire's still at #6, swap the ignition coil with another cyl.

Good luck

thanks, i knew there had to be a systematic way to figure it out. I knew it had to be one of the three, but i didnt know what was best. the only problem is that i dont have a way to check which cylinder is misfiring. I have a code reader, but it doesnt do live diagnostics.

**Spikito** · 11-01-2008, 02:28 PM

Originally Posted by spike669

If your car is a 3.8 check the wires.Also check the posts of the coils for rust or corrosion.

yeah i was told the 3.8 wires are supposed to have a heat shield on them, but i changed my plugs a few weeks ago and saw no such thing, i prob moved it when i changed them and it burned through

**Spikito** · 11-01-2008, 05:11 PM

ok so i got underneath my car, pulled the wire off, and the plug was loose, i couldnt twist it by hand pretty easy. So i pulled it out, it looked ok, so i put it back in. But the plug boot was full of carbon. i knocked as much out as i could and put it back together.

Car still misfires, but not nearly as often, or as violently, so tomorrow im gonna pull that plug again and really clean it, see if that helps.

**jigger1166** · 11-02-2008, 03:50 AM

An easy way to check which cyl. is missfiring is to use a water squirter (squirt gun), and when the engine gets warm, spray the exhaust manifold at the cyl. head. The misfiring cyl. won't steam as much as the others.

**sunsetorangess** · 11-02-2008, 05:38 AM

I picked up a little handheld thermometer for that reason. Check the temp of each cylinder..
J

**Spikito** · 11-05-2008, 06:21 PM

ok, i think i got it resolved, got out there today, replaced the plug and cleaned the plug boot, it had a shitload of carbon build up. I took it around the block and i got too little misfires, got pissed off and parked it.

But then a few hours later i took it too school, had to run up through the gears 4 times, and go up a serious hill, that hill has been killing me. had no misfires, on the way home i stepped on it once, ran it up to about 5500 through 1st and 2nd, no problems. So basically i went through all the scenarios that bring on the misfires, and couldnt get one, well see how tomorrow goes.

btw, with the misfires, i couldnt get over 3k, at that point i lose cyl 6 completely, and cant gain anymore RPM's