Sparks once or twice, then nothing (79 Spider)

Gotta love that wiring . . .
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bradartigue
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Your car is a: 1970 Sport Spider
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Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

I'm not stumped so much as annoyed that we've replaced a bad rotor, a bad pickup (frayed), and now find that either the ignition module or the coil is bad. Is a symptom of a bad ignition module sparking once or twice and then never again? I'm going to test the coil as well. I've actually never had so many ignition components fail on a Spider, looking back we should have replaced the entire system on day 1. Would have saved on shipping!
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RoyBatty
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Your car is a: 1975 124 Spider - 1971 124 Sport Coupe
Location: Locust Grove, VA

Re: Sparks once or twice, then nothing (79 Spider)

Post by RoyBatty »

Could be that one of the electronic components reaches a temperature that is a fail point when you are attempting to start the engine?
A continuity and resistance check of the coil should be able to tell you whats happening there. No?
Is it possible to swap in a standard non electronic distributor just as a troubleshooting test.
It's always nice to hear an engine run after you take some steps no matter how silly it may seem.
It can provide some inspiration. And sometimes helps with the troubleshooting process.
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toplessexpat
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Re: Sparks once or twice, then nothing (79 Spider)

Post by toplessexpat »

I had a coil on an old Renault that behaved like that. Maybe got three sparks out of it, and then nothing. New coil - problem went away.

A
---
Many classic Fiats - it's a disease!
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majicwrench

Re: Sparks once or twice, then nothing (79 Spider)

Post by majicwrench »

Really simple to decide if issue is with primary or seconday system. Hook voltmeter to neg side of coil, should go high and low. If it does, primary basicly OK. If no volt up and down, primary bad. Lab scope is easier to see volt change than voltmeter, but not everyone has a lab scope. Most of the time, both modules and coils are either good, or bad, rare to see one causing a three spark and not kinda deal. Are you checking for spark at coil wire??
Keith
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bradartigue
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Re: Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

majicwrench wrote:Really simple to decide if issue is with primary or seconday system. Hook voltmeter to neg side of coil, should go high and low. If it does, primary basicly OK. If no volt up and down, primary bad. Lab scope is easier to see volt change than voltmeter, but not everyone has a lab scope. Most of the time, both modules and coils are either good, or bad, rare to see one causing a three spark and not kinda deal. Are you checking for spark at coil wire??
Keith
Bad coil; your responses triggered a full test. The coil would apparently take enough charge for one or two good sparks then just go flat. I tested it before and after - before it was within the range, two cranks later tested it again and it was 0 ohms in the primary windings. So it's fried. Replaced it. Thanks for the prodding.

Now I have good spark all the way to the plugs, and the damned car won't start. Thinking bad fuel, it sat up for 4 months unprotected (outside) and just has all kinds of little things that went wrong, from these ignition issues, the starter, now down to thinking it's either the fuel or I can't time a FIAT properly any longer....frustration.
So Cal Mark

Re: Sparks once or twice, then nothing (79 Spider)

Post by So Cal Mark »

fuel should be okay for 4 months, unless it's full of water. Maybe the plugs are wet since you had no spark
dmwhiteoak
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Your car is a: 1972 Fiat 124 spider
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Re: Sparks once or twice, then nothing (79 Spider)

Post by dmwhiteoak »

Brad, check your plugs. I put new bosh plugs in mine and all 4 failed as I was timing the engine. When I finally had everything right it still would not start. Put old plugs back in and fired up and ran smooth. I would never have thought it.
Dennis Modisette

1972 124 Spider
2003 Chevrolet Z71
2007 GMC Yucon
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bradartigue
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Re: Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

This may have sat for 6+ months, and for all I know there is water in there. I'm going to fill it up with good gas and see later this week. The plugs, we're going to swap them. They spark well when placed close to the head, as they should. But who knows once they're screwed in...
vandor
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Re: Sparks once or twice, then nothing (79 Spider)

Post by vandor »

> but not everyone has a lab scope

There is an app and wiring attachment for an iPhone to turn it into an oscilloscope.
Csaba
'71 124 Spider, much modified
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http://italiancarclub.com/csaba/
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bradartigue
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Re: Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

vandor wrote:> but not everyone has a lab scope

There is an app and wiring attachment for an iPhone to turn it into an oscilloscope.
Very cool, I looked into one. Not my car so hard to justify the expense for this. This is...something stupid going on because the car sat for months and months outside. I am depressed that I can't sort it in my head though, I've never, ever had a Spider that wouldn't start - even poorly start - after all we've put into it.

By the way the Blaster 3 coil works well with the electronic ignition. It puts out some serious zap.
garion
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Re: Sparks once or twice, then nothing (79 Spider)

Post by garion »

Is this the same car you put that Chinese DFEV on? Could it not be getting fuel?
--John
1978 Fiat 124 Spider (for sale soon)
1979 Fiat 124 Spider
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bradartigue
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Re: Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

garion wrote:Is this the same car you put that Chinese DFEV on? Could it not be getting fuel?
Same car. It's getting fuel, the Chinese carburetors still chugging along just like the Spanish and Italian ones.
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bradartigue
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Re: Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

It now runs. It sat for months outside without being run and this is what I found - I've never had one deteriorate like this from just being outside:

The head gasket had failed. This wasn't from sitting but it let moisture seep into the piston bores. There was a patina of rust that we had to get out.

The starter was bad. The pickup AND control module were bad. The coil was bad. The rotor was bad. The plugs were bad from the corrosion inside the bores. The fuel had gone rancid. The fuel line, less than two years old, had rotted out, presumably from ethanol.

In the end it took a new starter, new coil, new control module, new pickup, new rotor, new plugs, new fuel, new fuel line, new fuel filter.

What I think is we had the "final failure" of a bunch of parts that were on the verge, and extended exposure simply accelerated the problem. Amazing how unrelated things can all go kaputt at the same moment.
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RoyBatty
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Re: Sparks once or twice, then nothing (79 Spider)

Post by RoyBatty »

I have been waiting to see this post.
Glad you resolved it Brad.
Well done. Now go drink several beers. You deserve it.
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bradartigue
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Re: Sparks once or twice, then nothing (79 Spider)

Post by bradartigue »

RoyBatty wrote:I have been waiting to see this post.
Glad you resolved it Brad.
Well done. Now go drink several beers. You deserve it.
thanks - the funny thing is the net result was a lot of easy work. Well, except the starter. Had I been less systemic in my troubleshooting I would have bought a new coil, new module, new pickup, new plugs, new cap, new rotor, new wires, and in about 20 minutes have had it all done!

BTW the gear reduction starters kick ass.
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