1968 Buick Special No Spark

1968 BUICK SPECIAL

84,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC

PETERF36

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I bought a 1968 Buick Special with 84k miles, a true "grandma's car" in very good shape. It is a basic 350-2 V8 automatic with no options at all except an AM radio and rear defroster fan. Although it ran well, I gave the car a comprehensive tune up changing spark plugs, wires, distributor cap and rotor. I updated the distributor with a breakerless ignition module from Pertronics and their recommended coil. The car ran perfectly for 6 months. About a month ago I went to the garage to start it and the engine would crank but no start. I checked to insure I was getting fuel to the carb and that was ok. I determined I was not getting spark to the distributor but I was getting 12 volts on the positive side of the coil. At a mechanic's advice I put the points/condenser back in the car with another new coil with the same results, the car will crank but not start. I examined the wiring harness and found some unusual splices so I replaced that, from the firewall to the engine. Now I only get 6 volts at the coil and the car still will not start. The alternator is new as well. I'm not sure what my next step should be, the ignition switch, voltage regulator, etc? Can you help?
Peter Fee

Nov 20, 2015 at 7:34 AM

HMAC300

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48,601 POSTS

with these older cars it should have 12 volts cranking and 9 volts once it starts. points shold be set at about .016-.017 or 30 degrees dwell to run best. if it sounds funny when you turn it over check for a bad timing chain as these were prone to it. if it has lasted as long as it has with no timing chain it is an amazing feet normally at about 50k these went out. they were plastic cam gears. check to see if rotor points to #1 then check compression on a few cylinders if they are all like 75 or same compression like less than 90 probably the chain is bad. Also check to see I you are getting spark from coil if you are then check rotor inside distributor cap as that probably is the culprit. it should still start with 6 volts however. see pic for firing order etc.

Image (Click to enlarge)

Nov 20, 2015 at 8:32 AM

CJ MEDEVAC

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11,004 POSTS

MY BUDDY SELDOM DRIVES HIS '48 WILLYS JEEP (I HAVE A '46 TOO!)

IT HAS BEEN CONVERTED TO 12 VOLTS (MINE TOO!)

IT HAS THE PERTRONICS IN IT (MINE TOO!)

ALL OF THIS "MINE TOO" ACTUALLY INSPIRED HIM TO DO HIS LIKE MINE!

THE PERTRONICS SYSTEM USES FULL BATTERY VOLTAGE TO THE COIL, NO REDUCTION NEEDED

THE POINT'S SYSTEM NEEDS RESISTANCE ON THE COIL WIRE (A BALLAST RESISTOR IS WHAT WE USED ON OURS)

WE LEFT THE BALLAST RESISTORS MOUNTED IN PLACE (IN CASE WE NEEDED THE POINTS AGAIN) AND SIMPLY PIGGYBACKED THE WIRES ONTO ONE SIDE OF IT, SO IT WOULD HAVE FULL 12 VOLTS TO THE PERTRONICS

BOTH OF US KEPT THE POINT SYSTEMS (COIL AND ALL) IN A ZIP LOCK BAG, JUST IN CASE THE PERTRONICS WENT BAD. I FIGURED 15-20 MINUTES TO DO THE SWAP IF NEEDED.

WELL,

ALVIN CALLED ME ABOUT A WEEK AGO, WHININ' THAT "BABY" WOULD NOT BUST OFF.

WE GOT A WEAK SPARK A TIME OR TWO THEN NUTHING!

WE SWAPPED BACK TO POINTS (ABOUT 10 MINUTES TO DO IT)

SAME THING!

I COULD LIFT THE POINTS AND GET A GOOD "POPPING" GOING ON, BUT STILL A WEAK SPARK

HE REPLACED THE PLUG WIRES (AND COIL WIRE) AND THE COIL TOO

SAME THING

SO WE TRIED THE LAST THING WE WOULD NOT HAVE FIGURED WOULD WORK

4 NEW SPARK PLUGS!

THAT WAS THE TICKET!

THEN WE PUT THE PERTRONICS BACK IN

GOOD TO GO!

HERE'S A LINK SHOWING MY JEEP WITH A PERTRONICS W/ BLASTER COIL

https://www.2carpros.com/questions/1972-volkswagen-beetle-should-intake-manifold-very-hot-touch

THE MEDIC

Image (Click to enlarge)

Nov 20, 2015 at 4:17 PM