Datsun Roadster Forum-311s.org

IT could be the module (black box) though they tend to be bullet proof. Check the connections inside the distributor where the red and green wires plug into the ignition box - follow the wires around to see if there is any chafing or bare wire. Check the external terminals on the black box, are the connections tight and dry? Check the terminals at the wire ends where the meet the coil are they tight and secure?
Also, I'll PM you the manual, which has a troubleshooting section and some electrical checks you can make.

Really does sound like a loose wire. Had similar symptoms last year (without the tach) and traced it to a bad wire connection. See if you can get it running and start wiggling wires.

The only ignition part I've seen that will peg the tach is a bad pickup coil, but only an electric tach. If you have the mechanical, that's odd, because it's mechanically tied to the distributor, so something like a bunch of extra sparks wouldn't confuse it, like an electronic tach.

Any chance it's something simple, like a bad plug wire or cap/rotor? is it worse in rain or high humidity?

Dave, I have gone through all my wiring. Not a lot to check, really. Everything tight and normal. The GB Dizzy only has the 2300 miles I have put on it so far. I was going to pick up a new set of plug wires to see it that is the culprit. So, how hot are coils supposed to get? After running the car for a few minutes, it was a little warm to the touch. I have heard that bad plug wires can hurt a coil. Plug wires are new as well. Hell, 90% of my car is NOS parts!

Kyle

Kyle, just a thought, have you checked you voltage output at the coil? If the alternator is overcharging funny things can happen to the ignition system - including getting a warm coil.
Check the voltage at each side of the coil and let us know what you get.

Do you have a timing light? If so, while the engine is running like crap put the light on it and see if you are getting consistent spark. How are the plugs looking... rich? Lean? Normal? In my experience, coils get warm in normal use; hot would be a problem. I went through this same kind of thing a while ago, changing out coils, ignition boxes etc until I finally found a wire under the dash (not obvious, took a lot of wiggling) that was grounding due to a long forgotten spade connector cover coming free and touching metal. I can send you a known good ignition (black) box unless someone close has one to loan you... I keep a spare or 3, though I have never had one go bad... they are usually all good or all bad.
I realize you have checked all your wiring, but it sure smacks of a bad connection issue. Of course, you can always RnR the plug wires and at least you will have a new set when the old ones wear out, and it would be one more thing to eliminate. However, check your wiring at the switch, at any connections you made, at the fuse box, inside the dizzy etc to see if you can get it to miss. In your original post you said the car just stops like you turned off the ignition (hint hint?). You can run a whole new circuit and wiring just to see if that eliminates the issue. It really would help to know if you get consistent spark or not, then you would at least know what system to trouble-shoot.

Also verify you have full battery voltage at the + coil terminal. You did put the jumper on the ballast resistor, I assume?

Greg, I have rechecked everything, including the wires at the switch itself. What other wire could be causing an issue? Since I have replaced the coil from my original post, it hasn't just up and died. Now random electronic tach swings in relation to engine missing. Then after idling for a bit, take it out, and everything is normal. Tach stays right where it should be and no engine missing. I will recheck the wires at the tach. I put a timing light on it. Seemed OK. When it was running a little rough, and pointing it at the timing marks, it didn't stay right on 20 degrees. Kind of jumped around a bit. I put the light on every plug just to make sure I was getting consistent spark from all plugs. The quest continues.

Coil + shows 14 volts. I removed the resistor and just joined the wires. Insulated with electrical tape when I first installed the dizzy. Everything has been running fine up until I got it out this spring.

If I had to take a guess, I'd say replace the pickup coil, they're cheap and easy to change, and try a module if you can borrow one.
Only other car I ever saw throwing extra sparks was a 4 cyl GM with a HEI. Had 4 extra waves on the oscilloscope and the tach went nuts. After checking every part, it was the pickup coil. Different physiclly fromm a Datsun EI, but same principles.

Without alternator charging, I get 12V on the + side. 14V when the alt kicks in. 11V at the - side of the coil. Just took it out for a run. Car ran great for a mile or so. Nice smooth acceleration. Then when I really hogged on it, it started sputtering, cutting out. Barely made it back home even under mild acceleration. Died in my driveway, took a few tries to get it to start, and then sputtered it into my garage. I think the last time I took it out, it started acting up after heavy acceleration. I'm running out of ideas.

Check the wires from coil to the dizzy. I had a similar problem with an old bmw it end up being a broken wire inside the insulation. When the engine torqued over on hard acceleration it would lose contact. Be sure to look at the crimps on the terminals at the coil and dizzy for damaged wires.

Paul

Do you still have the glass fuel filter? They leak air and cause that same problem, especially under load. Check your fuel lines if you have already replaced the glass one with a newer in-line. If you still have it, get rid of it; caused the same problem on my 67 2000 and I see you have basically the same thing.

The thing that doesn't make sense is the damn tach, making me think electrical. How much was the timing jumping around? A little is normal, clear misses are more evident. Maybe the jumping is suggesting some kind of dizzy issue. Still, please do check the fuel filter issue; I did all kinds of things before I got that one figured out.

This sounds similar to the issues I had with my 65 1500.

My issue ended up being flooding of the front carb. Turned out that my choke cable was too short and ended up leaving my choke partially open, even when the knob was pushed in. At start up it was okay, but after a few minutes of driving & giving it more gas (via faster throttle) it would eventually start flooding.

On my early car, the gas would start flowing to the ground, so I'd know that I had a fuel issue. Do your carb overflows go back to the gas tank, or down to the ground?

Maybe an easy test is to disconnect the choke cable, and manually make sure the choke is in the closed position on the carbs. Start it up, and see if that helps?

Dan

Gregs672000 wrote:Do you still have the glass fuel filter? They leak air and cause that same problem, especially under load. Check your fuel lines if you have already replaced the glass one with a newer in-line. If you still have it, get rid of it; caused the same problem on my 67 2000 and I see you have basically the same thing.

The thing that doesn't make sense is the damn tach, making me think electrical. How much was the timing jumping around? A little is normal, clear misses are more evident. Maybe the jumping is suggesting some kind of dizzy issue. Still, please do check the fuel filter issue; I did all kinds of things before I got that one figured out.

I've been wanting to replace the fuel filter (non-stock). The clear filter looks clean. The tach bouncing all over and sometimes staying pegged is associated with the poor running which still leads me to believe it is ignition related. One note: I have a classic instruments electronic tach. The instructions mention to connect to the (-) side of the coil as opposed to the (+) side. Don't most electronic tachs connect to the positive side? Maybe not.

Timing is not jumping around a lot. Can I get a "black Box" from the dealer?