Now that you've put new plugs in, if you pull them back out and take a look, they can tell you about which cylinder(s) are causing trouble.

 

this occured before i even did the tune up and the original plugs with 85k looked perfect.

 

Check for leaks. Not all misfires will throw a code or a flashing CEL, but you can feel the hesitation. Theres probably a leak of some sort hiding somewhere. Have you cleaned your throttle body? Start at the air filter and start movign through the engine looking for leaks in the intake path somewhere. All vaccum lines are replaced with silicone correct?

 

i replaced a few of them since they broke when i was doing the valve cover gasket but on the plate above the TB still have a few oem hoses.

its not a hesitation and but a rough rev after 4k but only under load. shes smooth if you rev it in neutral

 

I like Jonesy's thought. And you can't always tell which ones are bad. Take that plate off over the throttle body. A couple of them curl under there and you wouldn't see the leak unless you take that off. Might as well replace them. The hose is what.....$5 for enough to do your whole motor? Just do it all and eliminate that question. Don't miss the long one that goes to the vacuum accumulator in the left front fender.

 

ill go replace them all now - what would any of those lines have to due with the engine being rough after 3500 rpms on accel in gear but ok when in neutral.

 

Under load, the throttle plate is farther open than it is at the same RPM in neutral. With the throttle plate open farther, there is a better chance it's pulling air from where ever it can get it.

 

i replaced all the lines on the top plate - both a.i.r valve lines - FPR line and the reservoir line in the fender.

havent gone for a ride as the wife is out shopping ( **** me ) so im on daddy watch

 

I had this issue and resolved it by replacing the vacuum line going to the spherical chamber on the front of the intake manifold. Forgot what that part is called, but its vacuum line is somewhat hidden and I missed it when I replaced all the other vacuum tubing (non of the D.I.Y.'s mention it, either).

Also, replacing the two motor mounts, two transmission mounts and snub mounts help, though 90% of the problem was due to that line having a tiny leak.

 

i was wondering what that was also which operates a rod that goes into the front of the intake - mine seems a little bent so im not sure if thats the design of it or not

i guess its called a drive unit