04mustang

my idle seems to be slightly off. i mean it runs smooth but when sitting in the seat u can feal a slight fibration or shaking in the seat and the shifter. it takes of smooth and there is no vibration and no probs when i hit the gas. it seemed to start doing this after the pulley instal. could it be the harmonic ballancer is slightly off or could it be a loose plug or something else. i plan on checking my plugs soon. im hopeing they are the problem . help me out if u can thanx.

mdvaldosta

Its most lilkely from your pulley intall. If you used Steeda then you've got a lighter crank pulley. The factory unit is heavy for a reason - to help take out some of the engine vibrations. I bet if you turn on your A/C it goes away. If it was a skip it would still be there, with or without the AC.

04mustang

thanx MD

mdvaldosta

No prob, Ive got Steeda underdrives as well - very happy with them but, yea I have the same "slightly worse idle" problem as well. Concerned me also until I realized what was causing it.

04mustang

yeah thats what it was when i turned the air on it went away. thanks alot. also did you get my pm?

mdvaldosta

No I haven't seen a PM from you, I had alot built up I hope I didn't delete it. How abouy re-sending it k.

Obsol3te

?
I've got the steeda aluminum pulleys and my idle is as good as it ever was.

mdvaldosta

Is your idle at 650 - 700 rpm? Also this is for a 4.6, which may yield some differences. The idle issue is directly related to the pulley swap - the weight of the pulley and the flywheel help to carry over the engine between cylinder firing. With an idle as low as 650 rpm changing the flywheel (to a ligher one) or using a lighter dampner will usually cause a slight "lopey" feeling. Its not a skip. Its more of a lope.

04mustang

lopey lol yeah its lopey. would bumping the idle up a lil change anything? this idle wont hurt anything will it?