I've got an early 260z (dec 73 manufacture date) that will not crank. I've owned the car less than a year and don't know much about its history.

I'm sure its getting gas because I have glass fuel filter cartridges and can see the gas moving. I pulled a spark plug wire, inserted a screwdriver and held it near the block while someone cranked it to see if I was getting an arc. No spark. So I checked my ignition coil which is a high output Mallory coil. My ohm meter showed that it was resistive. So I took it to Autozone because they advertise that they can test it for free. Well they couldn't. Neither could NAPA. So how do you know if your coil is good or bad?

So then I thought maybe it could be something in the distributor. The contact points seemed fairly clean on the rotor and cap. Could it be the pick-up coil has gone bad? How do you test it? I thought about just replacing it but it costs 50 bucks. Any suggestions on troubleshooting would be greatly appreciated. I have very little knowledge and no experience in this area.

Marshall

You won't believe it but I just got exactly the same problem this morning on my 76 2+2 260. As soon as I know what it is I'll let you know. A friend told me to replace the Dist Cap first because the points have a very weak spark compared to the later model Zeds with Electronic Distributors. Hope it works but I'm not sure yet.

Check to make sure the points are opening when the engine turns over. If the hold down bolt has loosened, they may not be opening.

I have a single pick-up coil transistor type distributor. There are no points.

Marshall,

Why couldn't they test it? Is it because it's a mallory? Even if so they should be able to test it. I'm not 100% sure that it's the same resistance values as a standard coil, but if its not working chances are that it's open.

The Autozone part is a Wells unit. The part # is C840 and the values are as follows: primary .7-1.1 ohms

secondary 8.96k - 13.44k ohms

This test is done with a standard ohm/ multimeter.

Even though you have a mallory the test should still work if anything the values would be little higher. If the unit is bad it should be Megaohms or plain open. The Wells part is $20 here so the price should be the same or close. If you have any doubt on the resistance check $20 is cheaper than $50.

Happy testing!

Nate:cross-eye

I think the reason they couldn't test it is because they did not know what the output should be. They had no specs on the Mallory. I'm not really sure why the previous owner replaced the coil with a higher output "performance" coil. Its still running through the ballast, which I thought reduced the voltage so it wouldn't burn up the points. So whats the point? Why not stay with the original? I'm wondering if it would make any difference to go back to the standard coil.

Also, this didn't seem relevant at first, but I had a leak in my radiator and was not aware until it overheated. I had replaced the radiator just prior to the problem of not cranking. I'm wondering if I've burned up the water temp. switch. Haynes says that its a spark timing control system on cars with automatic transmission. I have a manual trans., so I don't know.

Maybe I should just start replacing parts until it runs. I think thats cheaper than having it towed to a mechanic and paying them to figure it out.

Or maybe this would be a good time to go completely to an electronic ignition setup. So many options.

Marshall,

You should be able to determine weather it is good or bad with the above information...if anything the values might be a little higher...I will try this tonight with a new Wells and a new Accel unit to see if I am right.

Chances are that you wont notice any difference going back to stock parts.

The temp switch I'm not sure about.

Good luck

Nate:cross-eye

Hey Marshall!

I did a little test last night with a standard coil (good) and an Accel coil (good) they both read the same. So before you toss out the cash go ahead and test the Mallory you have.

Nate:cross-eye

The coil should be easy to test in the car... First make sure that there is voltage present , there should be 12 or more volts getting to the coil. you can verify the coil by simply applying and removing that voltage. When the field collapses the coil should put out a spark. Coils do fail, but it is not a frequent failure. I would be much more suspicious of the module that drives the coil, or the pickup in the distributer.

Thanks CoastGuardZ for taking the time to do the test. It amazes me that you would not only take the time to give your advice, but also go the extra mile. I really appreciate it.

Anyway. I think my coil is good based on a good resistance reading and getting some spark. I think the spark was weak because my battery is getting low.

I agree with smg1404 that the problem is in either the pick-up coil or the module. Probably the module since its the most expensive to replace stock.

Again thanks guys.

I've decided to go with the MSA Crane "Fireball" electronic ignition kit. It replaces both the module and the pick-up coil. And its a whole lot cheaper than replacing both stock. I will post an update when I'm done.

Marshall

I installed one on my 71. It was pretty easy. I haven't had a chance to get things started yet -- I need to get my fuel pump installed.