I replaced my plugs with some autolite copper core plugs.

Gapped them to .25 and now with partial throttle I get a stutter from around 3.5k rpm to just over 4k rpm.

Any ideas?

I double check the connections everything looks good there.

 

I would first reinstall the old plugs and see if the problem persists.

 

throw away those plugs and get some ngk's
mitsubishi cars are notorious for misfiring on bosh, autolite, and other plugs
get ngk or denso

 

+1, same thing happened to me even running the NGK's. Re check your gaps and/or replace the plugs.

 

Get rid of the autolites.....sorry you wasted your money

 

No problem on the money cause they were like a 1$ a piece.

I will go today and get some denso's.

Thanks guys that is what I was thinking but I guess I just needed confirmation from someone else.

 

Ok so I learned to not buy plugs from Walmart.

I went and got some NGK 7e IX's.

They came gapped at .28 so I left them at that and installed them.

So far they are not causing any problems.

 

What heat range where they?

 

Glad you got the NGK's i was about to tell you not to get the Denso's also. i am running those plugs also and I love them.

 

IX means Iridium, so I'm glad you didn't try to re-gap them, because you're not supposed to mess with the gap on Iridiums...