setting the points' gap
 

my ignition mystery was solved thanks to the brilliant minds of pelican. the wire inside the distributor was broken. it took me a long time to find it, but i learned how to test the whole system in the process.

now i have the new points, but i am not sure how to set the gap correctly. if someone could explain the procedure or point me to an article that would be great.

thanks

The short answer is that you rotate the engine until the points are resting on a peak of the lobe in the distributor. You then loosen the points and slide them around until the gap is at specification and tighten it back up in that position. Since you have a CDI, all the points do is act as a switch to tell the CDI to issue a spark. The gap is not as critical as it is for a "Kettering" ignition system (i.e. non-CDI type).

Once you get the gap set, you will need to redo your timing as the gap and timing are related.

This article explains the procedure for a MB but it is the same for any car: http://www.mbzponton.org/valueadded/maintenance/pointgap.htm.. |Keep in mind that because you have a CDI, the stuff about the dwell angle and replacement of the condensor (you do not have) can be ignored.

Thanks Harry.

I always found it easier to set the points on the bench, all the manuals say to get the #1 cyl to TDC on compression, then remove the dist. but as long as you know where the rotor is pointing and don't rotate the engine w/ the dist removed that isn't really necessary. Just remember where the rotor is pointing and reinstall in the same orientation.

points are gapped w/ the point rubbing block(lightly lubed) resting on a dist shaft high point.

After reinstallation it's best to check dwell, high dwell is too small a gap, low dwell is too wide a gap.

dwell can be also checked and set w/o starting the car sort of like old Chevys.

thanks everyone.

do i need to unplug the vacuum to set the timing at idle or 6K rpm?

Idle timing is set with the vacuum connected. 6K test is done with the vacuum disconnected.

-Andy

Back when I had points in my car, I'd set them on the work bench also. I'd connect the distributor drive gear to an electric drill using an old bicycle tire tube, spin the dizzy, and use my dwell meter to set them.

Rex

There is another way: Since the cap is off the engine won't start. Put the points in place and tighten them just a little. Have someone turn on the ignition. As the dizzy is spinning, set a wide slot screwdriver between the two nibs on the points and spread or close the two segments until you get the desired dwell angle. Put the wire back on and retest. For a stock CDI, the gap is 38 degrees, +/- 3, so I usually set them to 36, and as the rub block wears, the dwell gradually increases to 41, when I change them. I usually recheck after about 1000 mi.