Ignition, no spark problem help!

PatPax · Post by **PatPax** » Sat Dec 12, 2015 7:53 am

Hi, could someone walk me thru troubleshooting my ignition and no spark problem. I have put in new points, condenser, coil, distributor cap and rotor. Still no spark. Please help.

DukeofDeere · Post by **DukeofDeere** » Sat Dec 12, 2015 8:07 am

Make sure you have power to the coil.
Look for any short to ground where the condenser connects in the distributor.
Metallic core wires are the only spark plug wires to use.

Duke

Stan Disbrow · Post by **Stan Disbrow** » Sat Dec 12, 2015 8:55 am

Hi,

Power flows from ignition switch thru coil to distributor points then to ground via the points. Spark occurs when points open.

The ILBD switch is rotary, and often they form a wear spot in the 'I' position. Meaning they don't pass power unless moved to the further positions.

Easy to check with a voltmeter where the wire attaches to the distributor.

If bad, I usually opt to run a toggle switch to fix this issue as changing the ILBD is a PIA. I just run a new wire from the starter lug to the new switch and then a new wire from the new switch to the coil input.

I call it a Bypass Operation.

You can leave the old wire attached to the coil, or leave it off. If you leave it off, tape it up since power may be present in the other switch positions, depending on how messed up the old switch is.

Stan

PatPax · Post by **PatPax** » Sat Dec 12, 2015 11:11 am

Hi Stan, what is a ILBD? (I know what PIA is ha ha) I don't mean to sound stupid but how should I do as you suggested "Easy to check with a voltmeter where the wire attaches to the distributor. " what should the volt meter read? I get power to one side of coil (both old & new coils) no spark points(both old & new) , condenser(both old & new) or plugs. I check ohms on coil it reads 200 ohms. New rotar does not fit as well as old, but old left marks/grooves on old cap.

Stan Disbrow · Post by **Stan Disbrow** » Sat Dec 12, 2015 1:07 pm

Hi,

Sorry. I should have defined that.

ILBD is what it says on the switch panel on most of these old things. Ignition, Lights (front), Bright (rear), Dim (rear). But, you didn't say just which Old Girl you have. So yours might be different....

You should read 6 volts or so where the wire goes into the coil from the feed from the power switch. You should also read that at the terminal for the points when the points are open. The voltage will drop when the points are closed as they short to ground.

The coil works by building a magnetic field in the primary winding when the points are closed. That field collapses when the points open. That, then, induces a mag field in the coil secondary, which is the high voltage side. There is a backfeed from this at the points, which is what the condenser is for. You can run without the condenser but the points will pit fairly soon. I mention it because you can disconnect the condenser if you suspect it and still get spark.

Now, if the dist cap is aligned with the rotor properly, the high voltage will travel up the coil wire into the cap, then thru the rotor and into the plug wire.

What you need to do first is make sure the primary side is correct. Power feed to the switch, from the switch, into the coil, out of the coil, and into the points. And, that the points are opening and closing with the dist cam as it revolves. This is where the 6 volt meter is handy.

Now, the coil can be checked with a spark plug hooked to the secondary and ground. If you get spark there, coil is good.

After that, using spark plugs out of the engine holes and laying on ground will troubleshoot the rotor and cap. You also need to verify the timing of the dist with the flywheel as well. If the dist is too far out of time, you won't line up the rotor with the cap and - no spark. Even if the rest of it is good.

I always start at the beginning with any of these no-spark issues. The battery. And follow those pesky little electrons around their little amusement park.

And, don't feel badly. My dear old Dad was the best mechanic and machinist. He could figure anything out, no matter how odd. But, when it came to electrics more invovled than his little pocket test lamp could deal with, he yelled for me to come with fancy meters and even an oscilloscope to Do It for him.

Oh, the scope? I added a probe jack to an inductive pickup on an engine 'analyzer'. That clips on high voltage wires and lets me 'see' all sorts of hops, skips and jumps of arcing wires, caps and rotors. But, those issues give one spitting and sputtering problems, not No Sparks at all.

Stan

fundytides · Post by **fundytides** » Sat Dec 12, 2015 9:23 pm

It's a long shot, but make sure the rotor is turning. I have seen the pin in the distributor coupling or the oil pump drive gear shear off.

jtrichard · Post by **jtrichard** » Sat Dec 12, 2015 9:38 pm

MAKE sure there is NO oil on the points..... if there was an oil film on your feeler gauge when you set the points they wont make contact = NO SPARK

halwelch · Post by **halwelch** » Sun Dec 13, 2015 6:59 am

I think Stan hit the nail right on the head. Had to wiggle mine for years. Then got so it didn't work at all in the I position and then not in any position. I just traced out the power and I wires and replaced that whole switch with a toggle switch. By the way my lights have long since been removed so I didn't need any light switch. Stan, I like your idea of using a scope to look at the ignition system. There's nothing like actually being able to see what's going on!

gregjo1948 · Post by **gregjo1948** » Sun Dec 13, 2015 7:13 am

Did anyone suggest checking for power to the ignition switch? gregjo1948

PatPax · Post by **PatPax** » Sun Dec 13, 2015 7:19 am

When I try to start it the motor turns over and I have power going to the coil, but no spark beyond that. IF it was my switch would it be turning over & trying to start? Why don't I have spark past the coil?

halwelch · Post by **halwelch** » Sun Dec 13, 2015 7:20 am

Never thought about that pesky fuse in the line from the battery. With that in mind, check the fuse. Then check for 6 volts on the switch, then check for voltage on the I terminal, then at the distributor. Still think the switch is the likely suspect although could be a bad connection or broken wire.

halwelch · Post by **halwelch** » Sun Dec 13, 2015 7:23 am

I was typing a message while you posted. Try replacing the wire between the coil and the distributor, the small one that the points connect to. Unless the points aren't closing and opening that's about all that's left of course barring a new defective condenser.

PatPax · Post by **PatPax** » Sun Dec 13, 2015 7:28 am

Is there a way to check the new condenser to see if it is defective?

PatPax · Post by **PatPax** » Sun Dec 13, 2015 7:39 am

jrichard, I will start by cleaning the points (with alcohol & qtip?) just to make sure there is no oil on them.
halwelch, I did replace the wire, I will try to find that fuse & check it out.
fundytides, I checked the rotor is turning new rotor left mark in new cap.

I am at a loss as what else to try. This is a 1964 2010 gas crawler.

HELP!

Stan Disbrow · Post by **Stan Disbrow** » Sun Dec 13, 2015 7:50 am

Hi,

Disconnect the condenser first. Then check for power on the points with them open. If you magically get it back, then the condenser is faulty.

Also, check for volts at the terminal on the coil where the wire heads to the dist. If no volts there, coil is open in the primary winding.

A main point (pun intended) is to have the points open when checking for volts past the coil. With the points closed, you have a short to ground and the resistance in the coil primary will cause the volts to drop.

You do not have to crank the starter when checking the primary of the coil, or the secondary with a plug on the end of the coil wire. You only need crank to check rotor to cap and plug wires.

The starter is not part of the ignition circuit. The battery negative lead attaches to a manual starter switch mounted right on the starter. There is no electrical relay (solenoid) like there is on more modern things.

Also, you do have this hooked up positive ground, right? If it is negative ground there will be a weaker spark from the coil than with it positive ground.

Also also, you are using Number 0 wire from the battery, right? Not Number 4 from the local parts store. The commonly available wires are way, way too small for the current a 6v starter draws. That leads to a weak spark. And, if this is coupled with a reverse polarity on the battery you won't have spark.

Stan

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Ignition, no spark problem help!

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