Thread: Bent plug tips and misfires

Hi all,
I've posted a couple of things on here about my 2000 GTP that I recently purchased..well I have a couple more questions if someone may have some answers...

First off..when I got it home...it was missing on two cylinders...we pulled all the plugs to see if there was anything noticeable..and boy was there:



put in 6 new spark plugs...still had the miss...hooked up a friend's analyzer to it..was misfiring on cylinders 3 and 5...

replaced plug wires on those two cylinders..still misfiring...
got some coil packs from a junk yard...put them in..still missing..

so I've been looking into some stuff...maybe injectors?...I have seen a lot of stuff about chipped pistons....not sure if that could play a part....

also...when we first started the car up.....it ran for a lil while then started smoking real bad from the rear of the motor...now almost as soon as it is started..it begins smoking....

any ideas?

I dont believe so..at least not that I can see

I would do a compression test....

I will have to give that a shot...not entirely sure what it is..I'm not velry car-literate lol..but I'll look further into it thanks

Originally Posted by Knightmare

I will have to give that a shot...not entirely sure what it is..I'm not velry car-literate lol..but I'll look further into it thanks

It's straight forward. You can buy the tester for $30 at an auto parts or surplus store.

Remove a spark plug, insert tester, crank engine, read compression. You need to disable the ignition prior somehow. Maybe just remove all of the plug wires?

Do not just remove all the plug wires, you can wreck the coil packs.. Remove the wire harness that connects to the coil packs..

as soon as it cools down I will give it a shot....I'll keep y'all informed

any ideas on the smoke pouring out of the rear of the motor?

Originally Posted by BillBoost37

Yeah..something is wrong.

Not trying to be a wise ass here, without some good info/history I'm not inclined to know how to help you. Was the car run hard and developed the miss? Did you just buy the car?

My one off the hip idea that I'll throw at you is for you to ensure that a plug wire from the middle coil is going to the driverside end plug on the front of the motor. Then, ensure a wire from the top coil is going to the middle plug. If those two are reversed, that explains misfires and unburned charges explains smoke from exhaust.

You said smoke from back of motor, though. That's easy to explain. A newbie with greasy/oily hands got that all over the rear exhaust manifold. Oil + heat = smoke.

How'd I do? c'mon..you know those plug wires being reversed would be a nice easy fix.

I just bought the car about 2 weeks ago..havent really messed with it much besides the things I mentioned...perhaps hamis-stated there is no smoke coming from the exhaust..just from the back of the motor....I will look into the wires..but I'm fairly certain that the wires are right

chipped pistons/cracked head....

I would just get a new longblock myself.

By the back of the motor, do you mean the firewall side of the motor? If so maybe valve cover is leakin oil onto the exhaust manifold...

Originally Posted by 2007gpgt

By the back of the motor, do you mean the firewall side of the motor? If so maybe valve cover is leakin oil onto the exhaust manifold...

yea..the side closest to the firewall

Did you get a chance to do a compression test?

No i haven't had a chance for a compression test yet..hopefully tomorrow...it annoys.me.i can't.work on it every day..but too many irons in the fire..soto speak...