Mryoung

'My 88 mustang starts right up no problem stays idle I can rev it up still no issue but on the road it it runs real rough especially from 4th to 5th gear and shakes another thing I have noticed is when I let it sit for a few weeks I take it out for a spin and it drives great. I took it to a shop and they said it's not my trans I already know that I had the whole thing rebuilt this past summer my dad says he thinks it's the fuel filter any suggestions? Also it feels underpowered in some areas but that isn't the case when I let it sit for long periods of time. Any help would be appreciated

87 T TOP GT302

If it feels like it is skipping, while going up a hill or lower rpm's it may be the coil going bad. I had to replace my years ago .