I have a 72 - basic 350 engine that I just got rebuilt. I having a problem with my points. Once I set the Dwell to 30 and then dive it - the dwell moves down between 15-19. Plus it is hard to start after it sits the whole night. Are these related? It runs great until I let it sit over night and it is very hard to start. Why is are the points moving?

 

Just wanted to bump this up once. Thanks in advance.

 

I can't come up with anything definite, just some suggestions:

Are you running the motor to set dwell or just turning it over with the starter?
Joe

 

If your dwell changes that much at RPM, then the chances are that the distributor needs bushings.

 

I am running the motor to set the dwell - after i set it to 30 and turn off the motor - the car starts right up. AFTER I drive it - the dwell goes back down to 19 or so. After I let the car sit - it is very hard to start.

 

So is the dwell of 19 and the car having a hard time turnover connected?

 

Yes.... well.... maybe. 19 is way too low.

Are the points new, no pits?

Good dwell meter or old beater?

 

Points are brand new (standard) and the dwell meter is a beater, but is accurate. Someone mentioned the distributor may need bushing. Where do those go?

 

Inside the distributor housing; the shaft is stabilized by these. Did this problem happen after installing new points? It sounds to me like the spring used to hold tenison on the points adjustment screw is not keeping the screw from locking. Replace the points with a different brand. If still happening, pull distributor and thoroughly check. Good luck.

 

If it needs bushings, it will have to come out and get totally disassembled for a rebuild. Worn bushings wouldn't be out of the question. Perhaps you can try to wobble the octagon shaped cam a bit. If you feel it moving side to side even a little bit, it's shot. The upper bushing is oiled by a resevoir in the upper part of the distributor that according to the service manual, "should last the life of the vehicle." Ha! Ha! after 30+ years in my car the "lubricant" had hardened to a solid cake of goo. I don't think they planned on these cars lasting 30 years.

Also check to see if the cam and rubbing block on the points are getting lubrication. There should be a felt wick with just a touch of grease on it near where the points are.

 

How many times have you made the adjustment from 19 to 30?

It would seem that the screw that allows the adjustment may be stripped or backing off.

My reason for saying this is that if you made the adjustment from 19 to 30, then you have to move the screw in one direction. When this happened again you have to adjust the points by moving the screw in the same direction as before. If this happened a third time, and you keep moving the screw in the same direction, one of two things should happen. Either the screw falls out of the hole, or you cannot continue to screw it in any farther, because it is at the limit of travel.

For check for this, remove the distripbutor cap before any adjustments and look at the position of the screw. Start the car and adjust to 30 degrees. Stop it and remove the cap. Look at the position of the screw, or how much travel may be left. Then run the car like normal for the time you said that it returns to 19 degrees. Take the cap off and look at the screw. Is it in the same position as the original 19 degrees, or is it at the same postion of the 30 degrees.

That may tell you if the screw is backing off or not.

kdf

 

The dwell does not change if you are just sitting there with the motor on and idling. It only moves after you drive it around for a bit. I have driven it about 10 miles and checked the dwell again, and it falls back down.

 

If the dwell is moving, then the point gap between the points has to be moving also. So something must not be tight or seated in the distributor. If it is always moving in the same direction is it seated on the baseplate correctly?

If the dwell was moving around, that is one time 19, one time 30, one time 25, then that would signify it was loose, or the distributor needs to be rebuilt due to excessive play.

Your problem is that the points always move in the same direction. Pretty soon it has to hit somehting due to limit of travel, or that it is not seated and falling back into position. Pull out the points, look at the springs and connections, check that something is not between the points and the set plate, then check dwell again.

kdf

 

i agree.....i wonder if the screw holding the points in is stripped....i have never done this put try cleaning it and putting lock tite on it.... what if when it gets hot its loosening up?

 

Thanks for all the replies - I will look at all that stuff tomorrow. I really do not want to go HEI - I just think it is the vacuum advance or like mentioned already - the bushings need replaced. Kind of stinks that I had to the get the engine rebuilt, but it is almost there. I might not sell it now!! LOL