this is a 91 formula w/350 tpi Wow, I am stumped... Here is the problem, seems like it happens more often after it is warm, but sometimes even when it is cold. There is a stumble on acceleration, sometimes it gets worse, sometimes it is not there at all, however it does seem to be occuring more frequently. I have had it act up, got a chance to throw a timing light on it, it was missing slightly checked all plug wires and they all exhibited the same miss.

Here is what I have done, hooked up an obd2 found nothing out of the ordinary, tps is in range, cts is in range, o2s operate normal, I have replaced the ign. module, coil pack, plugs, wires, cap, rotor, map sensor. I am truely stumped and tired of throwing parts at it. Any suggestions would be greatly appreciated.

 

no one has any ideas?