low end problem

[88lxi-shortram]

lately ive worked out my backfire issue, my fuel issue and found the leak in my trunk. but i still have a problem with my low end. the car runs smooth and drives great but from a dead stop when i give it gas it is very sluggish until 2500-3000 rpm then it picks up like no other. ive searched around and tryed checking the butterfly valve thing that runs the second runner.. it seems to be operating right but idk exactly how it should work. ive also had hard starts when its cold. ill turn the car over and itll slowly begin to fire up until fully running. before it is running it hesitates strongly until it starts... it kinda goes " buh, buh buh, buh buh buh, buh, buh, buh, buh, vroom. ive left the keys in for up to five minutes to ensure the fuel pump is creating enough pressure to start and still the same symptoms... any advice?

[Keachman1]

Sounds like a spark advance or timing issue. Check the vacuum lines to the vacuum advance to make sure they have vacuum and hook up a timing light to check initial timing and rev the engine with the timing light still connected to make sure it is advancing like it should. The hard starting is a sign of improper intial timing. Also check the spark plugs condition and other things normally performed during a tune-up. Leaking injectors will also flood the engine and make it hard to start.

[88lxi-shortram]

maybe spark advance, i havent checked it but ive already had a timing light on it and it all chekced out fine. the injectors are new, spark plugs are new and gapped at .35. i was thinking about playing with the dizzy timing to see if advancing or retarding a little could help as well... any more sugg. guys?