I searched and didn't find an answer to my question...here we go...I took my car to a shop because my timing belt had fallen off while driving..they checked it out and the compression test and leakdown test came back fine. So they changed my belt and I was fine...well it started to idle rough and be very sluggish...then it started to studder really bad...so I fixed my timing (it was a bit retarded) and it seemed to fix it until I got further on a drive and it would studder very very badly..I changed the plugs and gapped them at .042 or so...grounds are good, cap and rotor are good, plugs are new, wires are 700 miles old (motor is forged internals stock compression about 800 miles on the engine.) I check most of the "normal" problems..nothing yet..any suggestions? I also changed the fuel filter...thanks for the help and if you have any questions let me know!

 

bump it up for a stressful car!!

 

Check your fuel pressure. A bad fuel pressure regulator would cause a studder, a spudder, a mudder, and very often a bad udder. I'm such moron, but not about the fuel pressure thing.