89 2.3 missing under load/acceleration

[93stang347]

Hi this is my first post on this website but I have been on this site numerous times. My girlfriend has an 89 2.3L 5 speed mustang and it runs great but lately it has been missing under acceleration. When taking off its fine in 1st and going into 2nd and 3rd somtimes it misses and sounds like a drag car with its 2 step on. It has a newer pump along with wires, plugs, cap and rotor. I also changed the timing belt about 5,000 miles ago due to the old one jumping a tooth and being shot. When I did the timing belt I didnt know were to put the timing so I put it at 12 degrees and installed the spout.
Also the pump in it is a V8 pump cause I own 2 5.0L mustangs, but being a return style I didnt think it would hurt. This started will after all things were changed and not from any new change it ran great after belt and pump than this. Car runs starts great, Gets good MPG and seems to be good to go besides the one prob. If someone could tell me proper Fuel pressure and timing that would be a good start and or if some has had a similar prob.
Thank you guys,
Ryan

 

[93stang347]

Very nice website found both fuel pressure and timing answers in the tech library. Also the car is a single spark plug non coil pack, non MAF motor. The symptom is very consistent when it acts up meaning it sounds the same and hesitates in the same way everytime.