missfire detected in cylinder six on a 3.5L

'97 3.5L

i'm stumped....i have checked almost everything that relates to cylinder six. replaced spark plugs; wire checked out fine....switched wire w/ another cylinder and still cylinder 6 missfire; primary and secondary part of coil is good; replaced cylinder 6 injector...made no difference; power to injector is good; replaced couple of bad hoses i found; compression checks out; fuel pressure checks out.

i'm totally out of clues where to look now. any help would be greatly appreciated.

i forgot to add that when the engine exceeds 1000 rpm's....it doesn't missfire anymore. which made me think that it may be the fuel filter...but i would think that if that was bad....it would affect more than one cylinder.

Lightly spray some carburetor cleaner with the extension tupe on the nozzle around the intake manifold area around #6 and see if the engine raises in idle, you might have an intake manifold leak. This is common on 3.5's and will cause the engine to run rough/misfire at engine speeds below 1000 RPM.

thanks....i'll give that a shot