I have this wierd problem that pops up every once in a while with my
LO3. What happens is from idle the tachometer bounces around all crazy like and when im driving, under acceleration, the engine kinda bucks and it feels like its missing. If i keep the pedal down the engine almost stalls, but it drives ok if i feather the pedal a bit. whats happening here? it hasnt done this in over two months so i kinda let it go.

thanks.

 

tune up status??? IE how long ago and what brand cap, rotor, wires, and plugs........ we will see what we can do

 

A jumping tach is usually some sort of ignition problem.

 

Replace the ignition module inside the distributor cap. It is that thing that sits right on the base, and has the 2 pin plug on it i think, maybe 3 pin plug.

 

Cap, rotor, plugs and wires all replaced when i bought the car in September. Ignition coil, pick up, and ignition module all replaced a month later. I figured it was some kind of igniton problem but i dont know what it is because it comes and goes.

 

could be that module if it comes and goes, i would recomend getting a accel brand module or another one from jegs or summit, the ones at autoparts stores are crap in my opinion and i used to work at a autoparts store, i never got with OEM replacement parts, always upgrade on stuff like that

 

ok, any chance it could be a bad plug?

 

yea, especialy if they are boushs, if they are throw them at slowstangs as you pass, lol use ac delcos, i got ac delco rapid fires, if they arnt boushs clean the real good and see what that does, also check to see that your cap and rotor are good and clean

 

If the tach is bouncing all over the place, there is a pretty good chance it is the ign module. Even a new one can be bad, if you get it at a parts store.

I got a new Ign module and other stuff in my reman dizzy at autozone, but it is all "cardone" brand. No problems there, works awesome.

Autozone should be able to test the module to see if it is bad. You have to remove it from the car tho. Also, sometimes they test good, and can still be bad, because they will tend to act up more as the engine and dizzy get hot.

 

I went through the same things for months, every time I would replace the module it would clear up for a week or so. It got to the point I would just swap back in a "bad" module and it would run fine for a week. Ended up being a bad ground inside the dissy that I would jiggle every time i would replace the module. Tightened up the screw and the problems disapeared.

 

I used to get the same problem with my TBI & it was always a bad plug wire boot that would burn & acr to the manifold (GM rams horn). Replace the wire & it was fine. Check all of your wires to make sure they are not arcing.