1970 distributor-I'm finally stumped-help

LD wrote in article ...

I think you are getting much too "technical."

Exactly how much gap does a "1/2 turn" produce?

How far do you turn it to the right before you turn it back that 1/2 turn?

Couldn't you find a matchbook to set the points???

LOL!!!

Start with about .016" mechanical point gap - set with the points rubbing block on a distributor cam high point - then go for 30° dwell on a GM.

You can also set the dwell on any breaker points distributor at cranking speed. Just make sure the coil secondary wire is grounded so the coil "dumps" its primary, or you might get a false reading.

Bob Paulin - R.A.C.E. Racing Chassis Analysis Services

Thanks, but I've done this method for 33 years. Turn cw til runs rough, then 1/2 turn cc (or vice versa). Set it in the middle between running rough, too close or too far apart, if you don't have a dwell meter. It's in the book (shop manual) I've not had a problem until lately, so I don't think it's related to the point gap/dwell setting. LD

NO, but I've been known to set the timing with a stick (bumping the dist to get a little more advance/retard). That is, when I don't have my 1963, $1.97 Kmart timing light with me!! :-) LD

This might be way out in left field, but how about the wire that goes from the points to the outside. I have seen them crack so they work fine at idle, but as soon as the advance plate moves, the crack opens and the engine misses bad.

Mike

LD wrote:

I've also run points for 30 years (ie: on a 76 Harley).

When the po>

Why do you think it's in the ignition?.. what about fueling issues?

regards,

Jim

Because it acts like electrical. It skips, runs "rough" like inconsistant ignition, spark to the plugs---not like a weak fuel pump/clogged filter, where it would try to cut out or quit altogether, esp. at high speed/rpm's. thanks, LD

That's a thought. I had it break loose from the clip that attaches to the points one time, stopped me dead. Fortunately, I found it, fixed it and was back on the road in less than 10 minutes. I'll check that one real good. LD

Why don't you save yourself a big headache and go get you an electronic ignition distributor ,loss the resistor and go fishing.

just my 2 cents Jeff

Been there, done that, on ( Dad's) '69 GM 307. Every 5000 miles it would blow the muffler off. You need to do a point resistance test (voltage drop from coil pos to battery ground) with points closed and ignition on. Anything over .1 volt is excessive. In my case it was a missing (from the factory) ground braid between the advance plate and the dist case. A bad ground wire is VERY possible. Mr Goodwrench failed to find the problem even after the 7th set of points. I was an apprentice at the time, and Dad got fed up with the truck and the dealer and asked me to check it out. Found the problem in less than 5 minutes, and fixed it permanently in another 5.

And, it burns the points.

It's probably your factory hydraulic lifters bleeding off. They weren't very high quality lifters in the late 70's.

To do an accurate bushing test:

Remove the disributor, and check for play in the top and bottom bushings. Sometimes the lower bushing can go, and the top have very little play.

as for the burning points, two words: "Mopar resistor!" they can fail to full voltage, do a voltage.

Also, check the polarity on the coil, posative to the resistor, negative to the distributor. That's not meant to degragate your abilaty, it's an easy mistake to make when your having other problems.

Good luck and I hope this helps.

Refinish King