Author Topic: No ignition spark  (Read 1199 times)

Offline preaction

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No ignition spark
« on: July 08, 2018, 09:07:07 PM »
I ran into this issue today with a new to me car and motor that was running yesterday and only needed the distributor pulled and reset a tooth or two. The motor was running before changing the distributor location after the move I had no spark. I checked the coil for power and it has 12v with the points open and 5.85v with the points closed, car has a fresh battery key on power at the coil and crank and no spark from the primary system that is high tension lead removed from the cap and held to a cylinder head. To be safe I didn't know the condition of the points and condenser so I replaced both and still no spark. I may have been looking at this too long does anyone see what I'm missing  thanks Paul.
8F02R218047-  July 18 1968   Dearborn

Offline 67350#1242

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Re: No ignition spark
« Reply #1 on: July 08, 2018, 09:40:43 PM »
I would guess bad coil secondary.  The 12v and 5.85v at the Bat terminal indicate the points are working and that current is flowing through the coil primary winding.   Might try a different coil to dist cap wire to check that too.  Kurt.
67 Coupe SJ 11/16/66
67 GT350 SJ 2/01/67

Offline rodster

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Re: No ignition spark
« Reply #2 on: July 08, 2018, 10:11:00 PM »
Found on the interweb...

Here are the coil specs from the 1968 Ford Shop Manual (other years should be very similar):

Primary reistance: 1.40 - 1.54 ohms (75F)
Secondary resistance: 7600 - 8800 ohms (75F)
Current draw (engine off): 4.5 amps
Current draw (engine idling): 2.5 amps

1965 Dearborn Mustang Coupe
Raven Black - Palomino Pony
1967 Dearborn Mustang Conv.
Wimbeldon White - Red
1984 SVO - 2A

Offline Bob Gaines

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Re: No ignition spark
« Reply #3 on: July 08, 2018, 11:01:58 PM »
I ran into this issue today with a new to me car and motor that was running yesterday and only needed the distributor pulled and reset a tooth or two. The motor was running before changing the distributor location after the move I had no spark. I checked the coil for power and it has 12v with the points open and 5.85v with the points closed, car has a fresh battery key on power at the coil and crank and no spark from the primary system that is high tension lead removed from the cap and held to a cylinder head. To be safe I didn't know the condition of the points and condenser so I replaced both and still no spark. I may have been looking at this too long does anyone see what I'm missing  thanks Paul.
Odd that the symptoms manifested themselves only after the change of the distributor reposition. I would eliminate possible reasons associated with that change first. I would switch out coil to eliminate that for sure to be on the safe side. Ford yellow top coils very seldom go bad.
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline preaction

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Re: No ignition spark
« Reply #4 on: July 08, 2018, 11:31:12 PM »
Bob, you are right and its been my experience that I never ran into a yellow top coil that went bad until today its frustrating at times but following the basics and double checking got the engine fired back up.
8F02R218047-  July 18 1968   Dearborn