Distributor/spark problem

[dwk673]

I have a 1981 FI Spider that will not start (cranks but does not turn over). I seem to have narrowed it down to a no spark problem, i.e. I get no spark indication using an in-line spark plug tester on any spark plugs. Coil checks out (12V to coil and correct diagnoses on coil primary/secondary). In addition I can see spark on the tester if I put it between the coil and distributor. I've replaced coil electronic module and checked out the rotor, cap, and also replaced the mag pickup in the distributor. Still no spark to plugs. What else could be wrong?

Thanks!

[azruss]

you can get the magnet on the pick-up upside down. you should have a couple of grounds that connect to the intake plenum bolts. Make sure those are intact. Do you have the mag pick up gap correct.

[dwk673]

Magnet and grounds good. I think the gap is close but I could not align the trigger and mag pick-up exactly - how do you do that (I cannot seem to rotate the engine by hand using belts/cam wheels)?

Thanks.

[garion]

Hrm.. You say you see spark between the coil and the dist.. Did you put the tester before the coil/dist wire, or after? The wire could be bad.

[dwk673]

Back to my problem here. In answer to last question I had the tester after the coil wire, in front of distributor. So coil wire appears good (it is also little used, although 12 years old, but looks good/solid, resistance looks about right).

[So Cal Mark]

check the continuity through the rotor, some of those had a resistor built into them

[wizard124]

Check the continuity of the distributor, center coil contact to each plug. Test the resistances of coil and plug wires. Then, I would swap out the coil.

[dwk673]

I had a rotor with 5K resistor, it tested out fine. Also tested distribute and wire continuity, all looks good.

I'm totally exasperated, ready to go with all electronic ignition just to be rid of this problem (if it becomes available again!)

[dwk673]

Also, the coil is fine as I get spark from coil to distributor.

[spider2081]

I would replace the cap and the rotor. It sounds like one of them is allowing the high voltage to short to ground somehow. A carbon burn can be hard to see. It measures fairly high resistance but it allows the high voltage a path to ground reducing the spark to nearly nothing.

[dwk673]

OK, I will try that, but will make another call to Allison's about the distributor-less ignition system first.

[dwk673]

FInally got Spider started again. I had multiple problems going on I think. Replaced cap and rotor per suggestion. Still car did not start. I then checked and found that I now did not have 12V at coil from ignition (I had checked this before and all was good then). Then realized my dash warning lights did not light up when trying to start, so starting playing with wires on ignition switch and found that I could make dash lights come on/go off by moving the wires slightly. Once those lights on (and presumably voltage to coil) car started right up. Solder connections on back of switch look fine, so I'll be be further diagnosing/fixing ignition switch. But with wires wiggled and set just the right way, I can start and re-start car just fine now.

[spider2081]

The problem you are having is often traced to the connector right behind the ignition switch. I purchased a male push connector similar to the ignition switch pins. I push it in each of the cars side of the connector. Often one or more of the sockets in the connector have opened up over time and do not make a good connection. I remove the socket from the plug and using a pair of pliers tighten the taps.

[RRoller123]

Absolutely. Check C31 very carefully, it had my car randomly not starting, completely dead, "click of death".

[dwk673]

Thanks for these suggestions! I will investigate C31.