Weird ignition problem

Gotta love that wiring . . .
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alfredhamstra
Posts: 59
Joined: Thu Dec 11, 2008 3:23 pm
Your car is a: 68-Dino Spider 84-VX 81-Turbo 72-BS

Weird ignition problem

Post by alfredhamstra »

Hello there,
Got a weird ignition problem.
CSO, 1981
Ignition gives spark direct from the coil (test with screwdriver in wire connecting to earth)
But the 4 sparkcables dont give a spark at all
What can be wrong?
I put an new distributor cap and measured the rotor (6 kilo ohm)

The car was driving, then starting to misfire, running worse and then not at all...


Somebody have an idea?

Greatings from Holland

Alfred
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Odoyle
Posts: 440
Joined: Mon Dec 01, 2014 10:06 pm
Your car is a: 1983 Pinafarina Spider
Location: CA

Re: Weird ignition problem

Post by Odoyle »

I had an intermittent problem with the magnetic pickup module in my 83. If your is original I consider replacing.
alfredhamstra
Posts: 59
Joined: Thu Dec 11, 2008 3:23 pm
Your car is a: 68-Dino Spider 84-VX 81-Turbo 72-BS

Re: Weird ignition problem

Post by alfredhamstra »

Thanks for answering
The pickup should be good, measured it, 600 ohm (out of my head)
weird...how can it be that i have spark on the main ignition lead and not on the other 4....

Anybody got a clue?
(its nice weather and I want to drive :-)
GeorgeT
Posts: 379
Joined: Thu Feb 16, 2012 12:41 pm
Your car is a: 1982 Fiat 124 Spider

Re: Weird ignition problem

Post by GeorgeT »

Is the magnetic plate in the distributor right side up? If upside down you will have a problem.
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Weird ignition problem

Post by 18Fiatsandcounting »

If you are getting a spark from the coil-to-distributor cap wire, then your coil and magnetic pickup are likely OK. It sounds like you might have the wrong distributor cap or rotor, so that the distance from the end of the rotor tip to one of the 4 contact points inside the distributor cap is too large. Another possibility is that all 4 spark plug wires (or spark plugs) failed at the same time, but I think that's highly unlikely.

When you say you measured the rotor at 6 kohms, what do you mean? Between what two points?

-Bryan
spider2081
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Patron 2024
Posts: 3015
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: Weird ignition problem

Post by spider2081 »

Anybody got a clue?
You mentioned replacing the distributor cap. did you have the problem before you changed the cap?
Its possible for the rotor to have a carbon arc from is center contact to the distributor center shaft. When this happens the coil fires direct to ground inside the distributor. Can you try another rotor? The stock rotors have a resistor between the center contact and the outer contact for radio noise suppression. 6K sounds about correct for that value. I think radio suppression spark plug wires would add too much total resistance did you replace the wires when you replaced the cap??
alfredhamstra
Posts: 59
Joined: Thu Dec 11, 2008 3:23 pm
Your car is a: 68-Dino Spider 84-VX 81-Turbo 72-BS

Re: Weird ignition problem

Post by alfredhamstra »

Thanks all for the replies.
Yes..... you guys solved it... I changed the rotor, and she runs again.
So looks like only measuring the two pints of the rotor dont tell the whole thing.
Somehow there was a invisible crack or so...
It appeared while driving, got worse and stopped completely

Changed it with another one, started right up.
Changed it back to the old rotor: did not start.
So the trashbin is a bit fuller now...

greetings from Holland

Alfred
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