When you take the cap off the distributor and look just under the rotor... this brown circular thing about 1-1/2 to 2" in dia- sort of like a collar around the rotor shaft. Anyway, is it normal for this thing to move? mine moves about 1/2" clockwise/ CCW. thanks

 

Anyone???

 

Ignition module maybe...hell, i am a rookie, i might be totally off, but mine didnt move, it was held in place with two small screws

 

Your pick up coil resides under there. If your car has been feeling a little doggy lately it is remarkable how much of a difference replacing this part will make

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91GTA 5.7liter needs paint, I rebuilt the trans, engine is moded but old

 

I think you're referring to the reluctor, but it should be secured and not moving.

IIRC there is two screws holding it down.

 

Inside the dist. there is a brown shield that covers 4 poles, inside those four poles there is a magnetic wheel that creates a signal that the computer reads to determine engine speed to map fuel by. If you look close and see cracking in the magnet you will want to replace the main shaft in the dist. The pickup coil is under the mag wheel on the main shaft. My 5.7TPI w/slp headers to flomaster had a bad backfire under decell after rolling off the gas at higher rpms. Sounded so bad it embarassed me to do it, it also had idle instablity (read: ROUGH). Replacing the mainshaft, had to buy whole shaft because the magnetic pick up wheel is pressed on it from G.M., and the pick up coil it Ran better, it ran stronger, and now has no back fire. Throttle response improved too. NOTE : When pulling Dist. make sure you make or make good visual note where the rotor points before pulling up on dist. and once Dist. gear comes free from cam. Also get new seal for dist housing to block.
I'm done talking. Good Luck.

 

One more thing dont forget to mark Dist housing to block so the timing willbe close enough to start and then set BASE TIMEING back to run good setting (factory or otherwise.)

See YA!