Slight Miss??

[Joshschicken38]

yeah i have a 99 firebird 3800 obviously with the automatic tranny. shes got about 165000 on her, mainly highway if that matters. but anyway, it seems like after it shifts into high gear, 3rd or 4th it has a slight hesitation, like a miss, or its just not running smooth at all....any ideas??? maybe a cylinder isnt firing completely but it is really only at cruising speed in 3rd/4th gear. any help greatly appreciated!!

[hockeyman]

Last tuneup was...?
Fuel filter, air filter, spark plugs -n- wires, seafoam cleanout, etc.

[BobbyZ72]

Originally posted by hockeyman:
Last tuneup was...?
Fuel filter, air filter, spark plugs -n- wires, seafoam cleanout, etc.

This plus new coil packs, pcv, o2 sensers. Maybe a transmission filter kit while your at it. [img]graemlins/popcorn.gif[/img]

[Joshschicken38]

yeah i tuned it up in august i think it was....new plugs, wires, lower intake manifold gaskets, upper plenum and valve cover gaskets as well....

i did notice one coil pack seemed to have some corrosion or something cleaned it off and everything but the guy that helped me is a mechanic and said it could foul out so maybe that is whats goin on then thanks guys for the ideas.....

however what is the seafoam, and exactly what is the trans filter kit?

[Fbody3400]

Seafoam will get your thread locked

[BobbyZ72]

seafoam is a fuel system cleaner, a transmission filter kit has a new filter and a new gasket for the pan. It allows you to change the filter and remove about 6 quarts of fluid so you can top off with 6 quarts of fresh fluid.