Hi Folks,
Just had a general tune-up done on my '84. Decided to drop the car off for new wires/plugs, cap/rotor and oil change. Thought it would be a nice Christmas present for my little red sled. Well, it is actually running a little rougher at idle since the tune-up. Asked the mechanic what he thought of the poor performance after the tune-up he said "that it may be because I was using a plug that was too hot (Platinum V Groove) and that he changed the plugs back to the recommended plug. Does this sound right to you? The car was idling fine before. I just thought I'd replace the old ignition wires and plugs as they were getting old

 

Sure, running a hotter plug could have masked a running issue with the car. How rough is rough? I assume he plugged the wires back in the correct order.

 

Hi Doc,
Yeah, he plugged the wires in right, my only minor concern is that the car lost 100rpms at idle, a little rougher than it was. Idle was suprisingly smooth before at 950ish, now I'm idling at 900-. No big deal, although I didn't realize that the switch to a different plug would cause a slight reduction in the prior smooth idle. If I was sure that the hotter plug wouldn't be a concern for premature engine failures, I think I'd prefer the performance of the Platinum V plug, at least in reference to the way my car was running before.

 

Sounds like a simple idle adjustment to increase the RPMS' a 100 or so and you will be good to go.