problem:

while driving my engine speed changes constantly throughout all speeds/gears, this problem seems to clear up every once in a while then it happens again

actions taken:
replaced:
o2 sensor
air filter
ign cap + button
spark plugs

also did a fuel inujecting full service
also changed timing to 12 degrees, (where it was smoothest)

someone please help.

 

By no means am I a tranny expert, but this is my hunch.....

If you mean you're going 65 mph, and the RPM's hunt around from (example) 1500-1600 even though you haven't changed your throttle position, and the TC is in "lock up" mode, then it sounds like the clutch packs are on their way out.

When's the last time you changed fluid and filter?

I'd check on the tranny board just to be sure, but that's what I would suspect.

 

it's an AT so i have no clutch , and i mean i can be going 20 and it will frantically jump speed and 30 and it will frantically jump speed, i thought it was bad ign but i replaces most common problem items

 

Guess what - you've got a clutch. Several, actually. He was referring to the packs that engage the gears within the automatic tranny.

 

either tc lock up or the clutches you think you don't have are going bad

 

hmm sorry, but i didn't think i had one, i have rebuilt a manual trans, but never opened an, AT, however the problem reminds me of another i had, used to own a 86 mustang 2.3, now when my TFI mod. went bad it did something similar, but then after a couple of seconds of doing that it wouldn't run anymore until it cooled down, and then it would start and the engine speed would vary and jump around until i replaced it, but the car runs the engine speed is just really jumpy