GTMustang1996

Hey everyone!

I have been having trouble with my car lately and I've run out of ideas of what it could be. I have a 1996 Mustang GT 5speed and lately it will have its good days and its bad days. Some days i'll take it out and it will drive amazing, like a brand new car and other days it will run awful and I can't figure out what can be causing it.

A little about my setup first so you know what I'm working with. It's a 5 speed, 4.6L, JLT CAI, BBK H-pipe (no cats) magnaflow magna pack exhaust. All other mods are suspention. I have a Bama tuner that is up to date with tunes for all my mods. Recently replaced my intake manifold, due to the original one cracking at the thermostat housing.

What I have tried: I've run (91 oct) through her all the time i've owned her. I've put all different brands of fuel treatment and that doesn't make a difference. I've tried all my different kind of tunes, including returning it to stock, and that hasn't made a difference. I thought it could be a miss so I tried going through the coils and unplugging them one by one to see if one of them, while unplugged, wouldn't make a difference while unplugged, and i didn't have any luck with that. When i'm driving the car and get on the gas it hesitates and "chuggs" until you back off the throttle.

One thing I can think of that might be causing it is that the car is running to hot. It sits at the middle of the M on the gauge which my tuner says is about 198.

The video below is the car at idle while the problem is occurring. When you can her the clear "miss" or hesitation the engine twitches and shakes harder than normal idle. If you could check it out i think it would help greatly in determining what could be wrong.

Could it be a valve sticking?

Can anyone help me with this one? I'm no expert but this one has me baffled.

https://www.youtube.com/watch?v=GhHG...ature=youtu.be

347mav

When you replaced the intake did you remove all the spark plug wires at the spark plug and clean all of the coolant out of the spark plug holes?

GTMustang1996

I did take the coils off the plugs when replacing the manifold but i put shop towels in the spark plug wells before I removed the manifold in order to absorb any coolant that may have leaked out while removing the old manifold. After posting this I went around and checked the wells and some were dirty and had some moisture in them and some were not. To error on the safe side I went ahead and pulled each plug and cleaned the plug the coil and threads. I also put a little anti seize on the threads so they come out easier next time. I'll have to wait and see if this little bit of dirt and moisture I cleaned out was my problem.

Camster

I'm still thinking intermittent, or faulty under load,coil problem.