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Need Help. Car turns over, but will not spark!

J jackcarter1971Member
Hey Folks: I need some help to sort out what seems to be an ignition system mystery. Maybe I need an electrical engineer, or maybe just a whole new loom.. Not sure, but let me explain and hopefully someone can think of something new, that I have not already tried. So here goes.

Two weeks ago, while the car was idling in the garage, it slowly died. I fired it up again and all was good, then 10 mins later, it died again. However this time, it would not start... it turned over, and the starter was happily eating into the battery reserve. But would not start. DEAD.

It did feel on the run, just before it died, a little gutless... like it was missing something.

So since that time, I have tried various coils... nada zip nothing... did not help at all... even though the initial signs would point to a coil failure.. but nope.

I then changed the ignitor 3, happened to have another one handy, set the rev limiter, so knew it was functional.. dropped it in... but nope, nada nothing... still will not fire.

The poked around underneath... of course some ****er before me, had managed to chew up the loom pretty good, with random cables not going any place... but hey it ran like that for years.

That said, the starter solenoid, looked in bad shape and I believe that the ignition is switched through that... so replaced that too... And you have guessed it NOTHING. Will not start...

NO SPARK.

Is it me, does she want me to sell her sorry arse... or am I missing something very simple, that only the italians would dream up.

BTW, the ignitor 3 is set up with a live feed from the battery, switched through a relay... and yes, I have tried MANY relays.

The only thing I can think of and not sure if this is possible, is that somehow the ignition switch and or post ignition switch circuit is not working and thus it is not tripping/switching the relay to give the ignitor all the juice it needs...

So please let me know. I need to know as the car has been out of action now for way to long and for my own sanity I need to drive it... it needs to start, once again.

thoughts?

Cheers JC71
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joulesjoules"Racing is Life, anything before or after is just waiting" - Steve McQueen
Fighting these issues from afar is always hit and miss.... Here's where I start at some deductive reasoning...



Remove distibutor cap and check the rotor/distributor is rotating - if not it's a sheared distributor gear pin.

What distributor do you have? Check power to the distributor module.

Get the multimeter out and check juice to the ignitor or bypass relay with a direct feed and see if she starts.

Report back what you find...

Good luck,
Julian
J jackcarter1971Member
Hey Julian:

Thanks for advice. To date, I have checked that the dizzy is rotating. Took dizzy out today, to swap out the ignitor, so checked out the roll pin earlier. Also checked that the dizzy was rotating, just in case timing chain issue. All good.
I have checked the volts coming from the direct line from battery, it was 12:20v, that is what the relay is getting.
That said, I believe that the issue might be the trigger wire that comes from the ignition switch to the relay, that essentially switches the relay to pass the current through to the ignitor.
But I am on clear on where to start what to look for. Could it be the ignition switch itself? I ask, as the engine does turn over. So the starter is getting plenty of juice. But no spark.

Need help!!!! Need to know what other things to check that are part of the start and run circuit. Common things that crap out and the more unusual and how to isolate to solve from what is wrong, etc.

Cheers JC71
noquarternoquarterMember
Hi
You state it's spark, but are you sure? If it dies slowly, that sounds more like fuel related. Sparks are normally either there or not, not gradual. When it won't start, pull a plug, is it black or even wet with fuel? Then you have no spark, if it's very clean, it's a fuel issue. If plug reading is not something you're used to
( http://www.tuningmadeeasy.com/.../spark-plug-reading/ ) then the ultimate test is to take out a plug, put it back in the plug wire booth, lay it on the engine so it touches ground, crank the engine, then you should be plenty of sparks if it works.

Assuming it's a spark issue, it's probably electronic components getting too hot. While it would be nice to be able to tell you which one, my experience (not being electrical engineer you ask for) it's best to simply change components one at a time until the problem goes away. Not buying everything, but old coils etc, borrow from friends, if you have ignition box, take it off and rewire. Tedious, but works...

My $0.02 though is that you have a fuel problem, unless you've tested and found otherwise. Too rich, maybe a broken or hardened power valve, way too rich at idle, and in the end the excess fuel overcomes the spark on the plugs. Check the plugs...
Or even a vacuum leak, engines idling and then dying slowly can be vacuum leak (
http://www.tuningmadeeasy.com/...e-the-wonder-tool-2/ )
Just guessing from a distance... Smiler
Last edited by noquarter
J jackcarter1971Member
Hey Folks: So fuel starvation is not the issue... I have checked and double checked that. As in yrs past it did suffer from the occasional fuel line blockage problem.

So the issue is No Spark, as confirmed by taking the lead from coil off and holding it next to the block, etc.

What I need is to understand is all the points of possible ignition failure beyond the usual suspects, such as coil, etc. Points in the wiring, that can failure... specifically in the start and run circuits.

Anyhow, let me know and thanks for info to date.

Cheers

jc71
J jackcarter1971Member
I just replaced the solenoid... but have not run a direct line from there. I assume there is one that exists... and maybe that is the problem? I will run a new wire.

The ballast resistor is bypassed, for the ignitor 3 and it has a direct power line from battery via a 30 amp relay that is triggered, or should be by the ignition switch?

That said, could the issue be any of the following.

1. Ignition switch? (can it wear out in some fashion or get gummed up enough that it would not work specifically for the coil. Please remember the car turns over, so starter works just fine)

2. Control box?

3. the rear loom?

I also assume that if the starter is running that, I have a good earth. The braided lead coming off the back of the ZF to the body looks ok?

Anyhow.. more thoughts please.

Cheers JC71
J jb1490Member
quote:
I just replaced the solenoid

Since the starter "works", the solenoid didn't need to be replaced.

quote:
it has a direct power line from battery via a 30 amp relay that is triggered, or should be by the ignition switch?

Yes, the relay should be activated by the ignition switch.

quote:
1. Ignition switch? (can it wear out in some fashion or get gummed up enough that it would not work specifically for the coil.

Yes. There is one contact for the ignition and another for the start. When the key is turned to the start position, both the ignition contact and the start contact are joined (electrically) by a movable contact. The ignition switch can be removed from the car, carefully disassembled, and (in most cases) cleaned. I think that Larry Finch still has some NOS ignition switches for sale.

quote:
2. Control box? 3. the rear loom?

Possible.

quote:
I also assume that if the starter is running that, I have a good earth. The braided lead coming off the back of the ZF to the body looks ok?

Yes.

As I posted above, add a temporary jumper wire from the battery side of the starter solenoid to the input terminal of your ignition relay. If your ignition relay is a Bosch type, terminals 85 & 86 are the coil circuit. One of these two terminals goes to ground and the other is from a switched +12 volts source (ignition switch). Terminals 85 & 86 can be reversed, meaning you can ground either one and the remaining terminal receives the switched +12 volt wire. On the '71 cars, the wire from the ignition switch is the red wire coming out of a molex connector by the ballast resistor. You can also connect the jumper directly to the +12 volt lead that goes directly to your ignition (instead of connecting it to the relay).

If the car starts with this temporary jumper, you won't be able to shut down the ignition (turn the car off) with the key. You will either need to stall the car with the clutch (trans in gear, heavy foot on the brakes), or get out of the car while the engine is running and remove the jumper.

If you would like to PM me with your phone number, I will give you a call.

John
J jackcarter1971Member
Thank you... I will try this "jumper" set up tomorrow, or later in the week. That said, I am concerned that it is the ignition switch, as a few months ago, it started to feel a little stiff, or gummed up. I drive the car all the time, so it gets more use than most, I think.

That said, if I can not clean it up...what is the avg cost on a new one NOS? Plus, I am not sure who Larry Finch is...? Sounds like the man with access to some difficult to source parts.

Plus, how difficult is it to pull the ignition switch out?

Cheers

JC71
mangustamangustaMember
Jack,

A couple of things....

If the rear part of your ignition switch heats up to "HOT" when operating your car, lights on etc, it could be time to replace your ignition switch, or at least take it apart and clean it/inspect for damage to the terminals.

Ignition module: two bad ones?????? I'd carry two spares and a long jumper wire.

Ford DuraSpark: a bazillion station wagons can't be wrong! Smiler

Steve
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