electrical gremlin

Maclab58

Maclab58

Well-known member
Grrrrrrrrrr.:mad: for the second time in as many weeks my car has left me stranded. The scenario is the same, an hour of fun driving and then i turn it off give it a 30 min rest and go back to restart it, it turns over, trys to start then no spark. starter spins but no fire. it has a new coil, modern point distributor, wiring harness and switch. last time i let it set overnight, went basck the next morning and it fired up like there had never been a problem. hope it does the same tomorrow. suggestions?
 
The next time it won't start for lack of spark, check the voltage with the points open. You should have 6 volts on both coil primary terminals, and also on the movable points contact (with the key ON). If you get this, then close the points and check the voltage on the movable points contact (with the key ON). It should now drop to zero and the points side of the coil should also be zero.

When you say the engine had no spark, did you hold the coil wire about 1/4" from a head nut?
 
Last time this happened to me, it was the contact plate in the distributor. The plate that contacts the screw in line from the key. It wiggled enough to not make connection and then it would contract or expand or something and make contact again. I even had the local police push me a couple of times. Hope you find the problem soon!
 
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Good luck. Remember things can move with heat inside the distributor and find a ground. Do not WD-40 your condenser like me, a Dummy.

skip.

From another post...but-->

I have the two piece shaft and really good bushings as no slop. Inside the distributor, not much can go wrong. Pull the distributor, open it up, take it apart and learn it. Love it.

I use the modern upper plate with 1970 Ford V-8 points and condenser.

I left the original lower isolated plate that has the tang for the jacketed spring loaded ignition cable end to touch and make contact to energized the points.

That lower isolated plate also has a tang for mounting the original style condenser and a screw hole to secure the original condenser. That tang has been known [by heat or vibration?] at idle to touch the inside of the distributor body, shorting out the points. It can be bent inboard just a tad. Or a piece of silver duct tape between the tang and distributor body can act as a pad to keep that tang from sparking out.

It is imperative that the spring loaded brass jacketed ignition cable end that is isolated in a screw-in distributor end, not be screwed into the body of the distributor too far thus shorting out the points via the lower plate.

Either way, with or without that heavy armored corrugated protective pop-out tube with the jacketed ignition cable inside it, not be grounded going up to the points on the upper plate. Check, check, check, with a continuity meter.

Hint: Do not 'clean' the upper plate with WD-40, as this usually shorts out the condenser and that generally kills the juice to the coil, making for a weak or no spark at the plugs.

Hint: A small piece of paper under the rotor takes the wobble out of that assembly.
Hint: A ring of PVC electric tape around the bottom of the distributor cap takes the wobble away from the distributor body and cap. You'll have to cope around the pin under the cap. But it certainly firms up the assembly. No more slop and cocking of the distributor cap toward advance or retard.

I posted -->>Dinking Around Inside My Distributor for more information on the dist.

skip.
 
Mine stranded me once with no spark at night about a mile from my house. Had it towed home. Noticed the next day that my ammeter was discharging continuousely with the ignition on no matter where I put the spark lever after several attempts to start. Figured the coil must be grounded by closed points. Points opened and closed normally. Began to suspect the armored cable. Testing revealed that it was the culprit. Sawed of the ends with a hacksaw, replaced the cable between the ends with a lampcord and every thing ran fine. Did have to stack a few washers under the #8 stud bolt. Maybe your armored cable is grounding out. maybe not. Just something to look at.
 
skip said:
Or a piece of silver duct tape between the tang and distributor body can act as a pad to keep that tang from sparking out.

skip.
Click to expand...
Do not use duct tape as an insulator, some if not all brands will conduct electricity, I have seen it happen.
 
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