Datsun Roadster Forum-311s.org

okay guys I need some help. Today I was driving my 67 after it had been in th garage for months. It started just fine and drove just fine. Then I parked it went into mako's for an estimate...left and when I pulled out of the parking lot the car stoped. My gas is fine and my battery is fine...but I was getting no spark. How can I check to see if the coil is bad? Or do you guys know some other things I should be checking out?
thanks in advance,
Adam

The same thing has just happened to me today several times.
It happened suddenly, so I'm assuming its electrical, not a fuel delivery problem.

I found that the wire going from the points to the insulator on the inside of the dizzy body looked as if it was shorting out when the vacuum advance plate was activated.
The insulation on the wire was frayed and I taped it up , but the stalling condition re-appeared after 10 minutes or so. The wire might be broken inside its insulation, so I will be replacing it today.

If that doesnt do the trick I will be trying to tracking it down using the Chilton troubleshooting guide as follows:

Checking the ballast resistor or resistance wire for an open circuit using an ohmmeter.

Checking the condenser for a short by connecting an ohmmeter across the condenser body and the pigtail body(it must have infinite resistance).

Test the coils primary resistance by connecting ohmmeter across the coils primary terminals using the low scale. Should be about 1 ohm, if far from reading 1 ohm the coil should be replaced.

Test the coil secondary resistance by connecting ohmmeter across the distributor side of the coil and the coil tower. On the high scale the reading should be between 4K ohms and 10K ohms. If the resistance is considerably higher (ie 40K) , the coil will be replaced (note:values do not apply to high performance coils).

If I dont find anything out of the ordinary on the electical side of things, I will be looking at the possibility of fuel starvation. The fuel filter seems to be always full, so the carb float bowl valves might have to checked.

Does anyone else have have some more suggestions to add?


Ray B.

Also Check the wire leading to the Solenoid on the Starter, this get loose and comes off all the time.

Then check the power into and out of the Voltage Regulator.

Also, how is the power on the battery, is the alternator not working and the Battery is not charging when you drove it??

Lou Smaldino
66-1600
67-2000
65-1500

thanks for the help I am definitly going to check those things that you mentioned. I just wasn't sure what to look for with the voltameter and you said exactly what I wanted to hear. Just out of curiostity if it was the coil are these expensive? will other datsun coils work? And are there any aftermarket ones that work better?

I'm not sure if there is an Advance Auto Parts in your area but Coils with new mounting bracket are around 35.00.

You also might want to check your Ampmeter but if you didn't smell ozone then some wire has broken or come loose. Good luck, tracking electrical problems are a pain.

Datsun 182

It all depends what you are going for, I am a big fan of the EI distributor that Gary Boone provides, he provides a bigger coil and it does away with the need for the balast resistor. But IF you want to keep your vehicle stock, all our vendors have the necessary replacement parts and the knowledge to help you out.

Lou Smaldino
66-1600
67-2000
65-1500

Basic coils are pretty generic, just make sure you get one that's for a ballast resistor and the right diameter for the mount and you're in business.

But we don't yet know if that's the problem. I had no spark a while ago, came on suddenly. I found out it was the spade connector for the points wire on the side of the distributor. It had gotten so dirty and corroded that current wasn't passing through it. It's easy to check. If you're getting voltage to the small wire that attaches to the distributor but not to the points this is possibly the cause. On that same subject, the small braided wire inside the distributor that runs from that same spade to the points can get broken while the braiding stays whole. It's another thing to check.

If it fires but then dies as soon as you let go of the key, then you probably have a bad ballast resistor. The resistor is bypassed when you turn the key to START but then engaged when it turns to ON once the car has started.

Is the ballast resistor bypassed when the key is in the start position on all or most cars? I've been trying to troubleshoot that exact problem with my dad's '37 Oldsmobile Hotrod. I was thinking it must be bad wiring in the ignition or some such thing, but I'll check the ballast resistor next.

Thanks,

Datsun182

The stock equivalent external resistor coil I just picked up was $35.
Brandname Niehoff Power Pro #27437.
Box labelled with additional #'s PT210 , AL179 and coil body identified with the #'s 27473 and 0703.

Your situation sounds as if a component (or broken/disconnected wire) is fully out of commision preventing you from getting any spark, so you shouldnt have to replace the coil unless its tests out as being defective.

In my case, its an intermitten spark cutout, so I'm changing out components to see which is defective because I've done all the things that have been suggested so far.

My fuel delivery is good, but the spark cuts out at approx 10-15 minute intervals.
Separate multimeters connected to the battery and to the (+) & (-) terminals of the coil and my ammeter do not drop in voltage readings during the spark cutout.
However, my timing light does cut out when it starts to die.

Possibly an intermitten dead short in the points condenser (or coil) ?

jibha wrote:Is the ballast resistor bypassed when the key is in the start position on all or most cars?

Joe,

'63-'67 Datsun Roadsters, no the ballast resistor isn't bypassed when starting.

67.5 -- darn, I think it is bypassed... can not remember.

68-70 -- yes it is bypassed when starting.

On the roadsters it is pretty common to find a bad connection on the wire connecting up to the distributor's points. I always carried a spare wire with connectors that could connect from the "-" side of the coil to the "spade connector" on the distributor. Helped out one roadster by the side of the road one time.

With the Datsun ceramic ballast resistors. Years of dirt,vibration, rust will cause an intermittant connection. Take the ballast resistor off the car. On the bench undo the terminals, clean everything up with a little emery paper. I like using a little antisieze on everything when I put it back together (antisieze is either aluminum based or copper based, either workds fine). This helps in preventing corrosion from reoccuring. Reassemble everything.

As already mentioned those little fabric wires in the distributor do break after years of use. Not sure if you can find replacements, but a super fine stranded wire can be used for that purpose.

(Joe... on your 1936, I suspect it is NOT bypassed. 6V system?)

Tom

Tom,

No, it's a 12v system. The body is on a 73 Chevy Nova front clip, with the wiring harness from the newer car.

I'll check go ahead and check the ballast resistor or try to decipher the electrical diagram to see if it is bypassed, thanks for the ideas.

Well guys I finally figured it out. I know it has been a while but i have other projects too. I got out my multimeter and started checking some things. and while I was moving some things around 1 ground wire started sparking with the key in the iginition. It was one of the grounds that came up to the dist. cap. Basically it was just really dirty, so i cleaned it and it started up just fine.

A quick 2 1/2 cents,

The 311 roadster uses a 12 volt system on everything thing except the ignition ...go figure.

The use of the ballast resistor steps the input voltage from 12 to 6 volts, for use of the 6 volt coil. You can simply remove the ballst resistor and the short wire to the coil, and replace the 6 volt coil with a standard 12v coil or a high output version coil. (40K volts will work most street enginges nicely) Then just hook the old input (12v) wire from the ballast to the coil + (and don't forget the 12v wire from the starting bypass as well ) Install a fresh set of points and 12v condensor.

If anyone is using a 12v coil with the ballst resistor still hooked up, you maybe having issues with fouling and lack of performance.

JC

That's a good 2 1/5 cents!!!

I am new so please understand when I ask...where is the ballast resistor? what does it look like?