The Stovebolt Site Forums The Shop Area Engine Shop 46 216 won't start.

My truck was running fine then hiccupped under acceleration. Then just stopped. I thought it was fuel related because I was getting spark. Seemed week but I don't know what a 6V coil spark looks like?. Now when I checked it again still have coil spark but no spark to the plug. Reset points. I have 6V through the coil. Can the condenser cause this? I have never had a condenser fail. Bad coil? What are peoples thoughts on the reversing switch. I removed my switch and set up the distributor correctly. I put 700 miles on the truck since I first restored it. Figured I would recheck the timing and put in a new condenser and points. Then the coil if needed. Are there 6V electronic IGN available?

The reversing switch was such a good idea, even GM decided to remove it! Made such a little difference in the wear of the points, it didn't make sense to add all those expensive parts. If your truck ran fine without it for 700 miles, I wouldn't look back.

As to bad condensers, heck, I hear they show up bad out of the box now more than ever. And yes, I think it can kill your spark. Easy fix, may as well replace it and see. I'm not even certain it matters terrifically whether it's a 6 or 12 volt, but my local carquest usually has a "6-volt" model on the shelf. They're technically rated in microfarads I think, which is supposed to be matched to your coil, at least for optimum point life. BUT, ANY working condenser ought to do the job.

My $.02, anyway. Somebody smarter will come along and educate us both soon.

-Michael

Please elaborate a little on the above statement. Are you saying there is a high voltage spark from the center coil wire, but it's not getting to the spark plugs, or is there no spark at all from the coil wire? The only thing between the center coil tower and the spark plug is the distributor rotor, and it can develop a short to the distributor shaft. Try changing rotors, or at least look yours over with a strong light up inside the hole where it slides onto the shaft. If you see a tiny charred hole, you just found the problem.
Jerry

Thanks. I,ll check the rotor. There was spark off the high voltage coil wire but it seemed weak. I cleaned the cap and rotor but I did not get a spark from the plug wire to the plug.

Well rebuilt the carb. still did not start. Replaced the points and condenser and it fired right up. Only 780 miles or so on that set. I bought those from one of the old chevs supply house. The new ones are name brand from NAPA. I don't like the look of the center contact of the cap. Its eroded away. I have never seen that before.

A cap replacement is in order as well as the rotor. They do get eroded after time. And the sooner the better, that could explain your points lasting such a short time if they even needed replacement.

Very strange. They were all new only 780 miles ago. Right after the restoration. Thinking poor parts but time will tell.

Poor parts is likely correct. I had problems with new ignition parts for these truck wearing prematurely. These problems were solved with NOS parts.

If polarity is reversed on the Points...I t-h-i-n-k that can cause rapid erosion...

Are you suggesting that the coil is wired backwards? Wire from the ignition switch should be (+), and the wire to the distributor should be (-). Will there be any spark at all if the coil wires are reversed? (which is real easy to do with the 216 upside down coil arrangement.) I am asking this because I do not know.
Carl

if the center contact on the cap is fried, likely the rotor tab wasn't putting enough pressure on it so there was arcing - I always pull the tab up a bit when replacing a rotor to insure it makes tight contact ..... point polarity - there was a setup back then sometime that would automatically reverse polarity to extend points life, don't know how that was arranged, and maybe it was just a GMC thing

Bill

Thanks. I have a new cap rotor,borg warner, should be good. I,ll pull up the center contact to be sure this go around. I have the reversing switch but did not install it. In my mind just another contact to fail.

Wires on the coil reversed will do little either way. No real harm. But, coil is designed to work with the proper current direction so I would think there might be a small advantage with ignition to + and - to the points. Has to do with the field collapse and the induction to the secondary coil. The fancy word is hysteresis loss. Just a way to measure how efficient the coil/transformer is working. Might make the coil run a little warmer, and it might not. Reversing switch? Might keep the fan motor running the right way? Just kidding I have no experience with a set up like that.

My coil is correct. The idea behind a reversing switch is to minimize the material transfer from one side of the points to the other. DC the current flow is one direction.

The condenser is what the engineers put in to keep material from moving from one contact face to the other. Reversing current might be helpful if the value is off a bit. I did not think of that. Thanks.