Timing

[78Southwind]

I have a GM distributor that has been re-curved for my 468 Chevy Southwind. Recently, the intake manifold was changed and we needed to reinstall the distributor and we noticed that the initial is @ 13 degrees but full comes in around 2800-2900 however, it very sporadic around 32-33 degrees.
What would cause full to be sporadic shouldn't it be consistent?

[atomickitn]

hey southwind check your the module inside the dist if your using hei style, or your coil could be going out. :idea:

[sanger rat]

Springs are to weak

[CARLSON-JET]

Both the above replies cover 3 of about 10 reasons a dist. will bounce.. to get a better feel of whats going on, more info would help...not knowing your motor set up anybody would just be taking a good guess or relaying past expeireinces. what kind of dist. is it? what are you using for cam timing components .. age of motor, dist. chain, gears ect would be helpfull. bouncing or spuratic timing issues have been an age old fight with motors which is why alot of racers use the crank trigger set up .. it just takes one more equation out of the puzzle.. did you have the dist worked over when you had it recurved? there are a few key parts in the advance mechanism that can contribute to this problem .. everything on the dist must be working smooth and the tolerances need to be tight. if the shaft is able to move up and down or the cam "walks" that will greatly effect timing. cam walking is corrected by a cam button... shimming the gear on the dist. stops the shaft from jumping up and down ... others will chime in and I bet we see at least a dozen reasons this could be happening... post more info ... the more everyone knows, there's a better chance of resolving this issue faster.. R.B.