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1971 240Z - starter problems


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Bro's '71 240Z ran fine the last time he drove it 5 months ago. Now won't start. Sat curbside undriven too long and battery bites. He's tried starting with an external battery, made noise like it wanted to start but didn't. A few years back when this happened, replacing the battery and spark plugs did the trick. He then also replaced the spark plugs, but still no go. The auto store that sold him the spark plugs said they're not the same as the previous ones, but were better.

Any ideas?

Trying to help him sell it, and this no start surprise bad news. Of course, it may also be a problem because it's the original setup and non-locking gas cap in a time where gas $s is outrageous, people have been taking the gas out.

We're also now trying to decide whether it's best to have it towed, full diagnostics run to decide how much to put into it before selling it for it's improved worth. None of us have any of the skills and knowledge to do a lot of this at this point alone.

Thanks so much for any help you can give us.

This link shows some pics, including the engine stuff. In one other forum, I just read that a biodegradable product in grocery stores called Simple Green is useful and safe to help clean up the engine, and might try that also.


LOL With so much to learn, and so much to do, have to laugh lots at the stumblings along the way.

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The auto store that sold him the spark plugs said they're not the same as the previous ones, but were better.

Translated that probably means that they don't have NGK B6ES or BR6ES spark plugs which work best in your car or any S30. What kind of spark plugs did they sell you? The brand of plugs wouldn't stop it from starting but they aren't 'better' than the oem type. Do the usual checks, spark, make sure it's getting fuel, etc. before you take it to a shop. If it ran 5 months ago, it just needs a little TLC to run again.

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seems like a few of us are having similar problem - it's a matter of eliminating what it's not. In my case, I knew I was getting spark, I have a fully charged battery and gas in the tank. Car started just a month ago, so nothing radical has occurred. As Steve says, check to make sure you're getting spark (take the plugs out of the head, leave the wire connected and ground it by touching the exposed area of the plug to something like the rocker cover - then crank the engine and you should see spark), eliminate the obvious.

I actually sprayed starter fluid into the carbs and the car fired, but once the ether burned off, it died. Clearly, I'm not getting fuel, which is either fuel pump or carbs. I know the fuel pump had some gas in it, implying it's getting it from the tank, but per Steve's recommendation, I will put the line going to the carbs into a bucket to see if it's sending (I am certain that's the problem).

If I discover that the fuel pump IS working, then it must be carb related. These cars are pretty simple to work on, just eliminate the obvious and go from there. GOOD LUCK!

The real question is when did the full moon come out to cause all these non-starters? ;) I was trying to sell mine, now this will push that back a bit as well....

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Try spraying some starting fluid in first. This will tell you if it's fuel or ignition.

If it's ignition here's a copy of a post which might help you test the ignition. This can be carried out in about 10-15 minutes.

Here's a quick checklist for troubleshooting ignition probs on a stock 240Z. This assumes that failure is not a result of replacing parts incorrectly. This is the quickest approach to resolving probs IMHO.

IF/THEN for a no start/ignition suspected situation...

1. Use new plug to check for spark at plug wire. (Lay test plug on ground. Look for hot blue spark when cranking.

1a.If there is spark then remove check the condition of plugs. Clean or replace if necessary.

2. Check for spark using new plug at the end of coil wire. Look for hot blue spark when cranking.

2a If coil has good spark then check/replace distributor cap and rotor.

3. Verify voltage going to coil when cranking. (Use voltmeter) Verify coil is wired correctly (+ to +)

4. Inspect breaker point faces for pitting and resurface or replace if any. (resurface with 220 grit buys a little time but the points will pit faster)

5 Set gap on points .018-.022. Verify that all wires connected to the points are in good condition and not frayed.

6 Replace condenser.

7. Check coil wire with ohmmeter. It's easier to try another wire if you have on handy.

8. If still no spark then check coil internal resistance. disconnect leads from coil. Set Ohmmeter at proper scale and it's test leads on + and - You should see 1.5-1.7 ohms

Next stick one lead on the "-" post and one lead to the coil output terminal it should read 9.5 -11.6 ohms. These are figures for a STOCK coil. Other coils have different values. Replace the coil if it is outside it's values. Coils for 240's are as cheap as $25 for a generic. It might be easier/faster to have a spare coil on hand.

9 Check distributor shaft for play. Use a dwell meter to dynamically test the breaker points. If dwell varies outside the 35-41 degree specs and the points are gapped right then distrubutor bushings need to be replaced. (Or replace dizzy)

I might have left something out having typed this up at 1:30AM. Hopefully it will help you or someone else in the future at least. Here's another tip..

If the engine is missing/misfiring and you think it's a fouled plug use a timing light's inductive pickup. With the engine running clamp/unclamp the pickup over each wire and observe which plug does not cause the light to flash.

Note that if the engine starts ONLY when being cranked it is possible that the ignition switch or ballast resistor is bad. Test the resistor (1.6 ohms) and test for voltage on both side of it with ignition "ON" and car not running. Coil gets 12V when starting and once the key is turned to "ON" the power is routed through the ballast resistor giving the coil 6volts. This keeps the coil from overheating/dieing.


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Just one more thing. If you don't have any starter fluid. Spray some WD-40 into the intake of the air cleaner. About a 10 second shot and then see if she will fire start. If she does or tries to run you know it is not spark related but fuel.

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