'73 240z - No spark from coil

[StinkyCheese]

I tried removing the spare condenser, that didnt change anything.

When i have the distributer cap off and crank the motor, shouldnt I see a spark every time the gap opens and closes? It seems to me I've seen that before... Right now it doesn't show a spark, ever..

I don't have access to an analog meter. I don't want to declare the new coil bad, it cost me $50! Maybe I should order the "flamethrower" that everyone seems to love and take the one I got back to napa?

[StinkyCheese]

I also opened the gap manually, no spark. when i crank it the gap definately opens and closes.

[FastWoman]

You could also wire a 12V light in place of the coil and see if it flashes on and off when you crank the motor. That would tell you the same thing.

[Jetaway]

I'm going back to the original post where Mr. Cheese described the car overheating, cooling off a bit, but then dying a quarter mile from home. He tried starting it at that time and it didn't start.

I'm thinking the overheating has something to do with no spark, but what?

The overheating could have taken out the coil, I guess, but that's been replaced. In fact, I think most, if not all, of the usual suspects have been rounded up to no avail.

Could the overheating fried some insulation someplace in the ignition circuit? Or expanded metal one too many times and created a loose connection?

Or, maybe the overheating and no starting is a coincidence. One of the bonuses of having a 30+ year car.

Chris

[StinkyCheese]

Good news/bad news. Good news- I have a spark now! Bad news- I don't know why. There is a wire that goes from the points to the side of the distributer (positive side?). This wire looked worn so I took it out and put in a temporary wire. Couldn't get a spark then, either. So i went to put it back in and i dropped a washer down next to the distributer shaft. I had to take off the points to get to it. When I got it all put back together I had a spark.

I'm irritated that I don't know what fixed it. I'm still confused.

It still isn't running. I know the spark is working, but i'm not getting fuel. I knew tis was coming - every time I went I cranked it I expected to smell unburnt fuel, but I never did. I can usually see fuel percolating in the fuel filter, but the fuel filter looks dry. I cranked it floored for a full 2 minutes and no fuel in the filter... Now I get to figure that out...

THANKS to everyone who offered suggestions. I am so grateful that there are people out the like you who care enough to answer an amatuer's distress call! You're all awesome!

[FastWoman]

Wow! Could be anything. Hopefully you fixed a bad connection somehow, and the problem won't leave you stranded 30 mi from home.

I think Jetaway is right that it's a temperature-related problem. Thermal expansion and contraction will often rear their ugly heads in a coil winding. Once you do get the car running, let it idle on a very still (not windy) day until it is hot. Shut off the engine, and then try restarting it 15 min later after the engine heat has soaked the engine compartment (with the hood closed, of course). Also try starting your car when it's bone-cold.

I think Jetaway might also be right about insulation. Carefully check the insulation around any of the wires you might have touched when you accidentally fixed the problem. You might have had a short to ground.

My money is still on the ignition coil. If you hooked it directly to the battery and bumped the (-) to ground, you should have gotten a spark out of the coil.

Regarding your fuel issue: Is your pump electrical or mechanical?

"THANKS to everyone who offered suggestions. I am so grateful that there are people out the like you who care enough to answer an amatuer's distress call! You're all awesome!"

There are a few pro mechanics on this board, but I think most of us are hobbyists/enthusiasts just like you. Two heads are better than one, and multitudes of heads, sharing ideas, experience and information, become absolutely brilliant!

[SteveJ]

Good news/bad news. Good news- I have a spark now! Bad news- I don't know why. There is a wire that goes from the points to the side of the distributer (positive side?). This wire looked worn so I took it out and put in a temporary wire. Couldn't get a spark then, either. So i went to put it back in and i dropped a washer down next to the distributer shaft. I had to take off the points to get to it. When I got it all put back together I had a spark.

That makes it sound like collapsed points were your problem. Taking them out opened them up. Check the gap and dwell on the points.

It still isn't running. I know the spark is working, but i'm not getting fuel. I knew tis was coming - every time I went I cranked it I expected to smell unburnt fuel, but I never did. I can usually see fuel percolating in the fuel filter, but the fuel filter looks dry. I cranked it floored for a full 2 minutes and no fuel in the filter... Now I get to figure that out...

Flooring the car while starting does nothing if you have roundtop or flattop carburetors.

Spray some starter fluid down the carbs and see if the car wants to fire then. Otherwise start going through the FSM on the fuel system to see what the factory diagnostics are for the fuel system. (I don't claim to have much knowledge on the fuel system, so if I was tackling the problem myself, that's how I would start.)

[Zed Head]

The points have to be grounded to flow current through the coil. I think that they ground through the mounting screws, or a wire off the points bracket (haven't even seen a set of points for many years). Maybe you had a poor ground for the points. Might be worth testing with an ohm-meter to make sure you're not on the edge.

Also, as I recall, the condenser used with a points distributor does more than noise reduction. It keeps the points from arcing and pitting by absorbing the first surge of voltage when they close again.

Edited February 27, 2011 by Zed Head

[gibson99]

(secondary condensor in picture) with the blue wire ,does this go on the neg or pos of coil.

Dave

Edited March 25, 2012 by gibson99

[beermanpete]

[ATTACH=CONFIG]52295[/ATTACH]

(secondary condensor in picture) with the blue wire ,does this go on the neg or pos of coil.

Dave

Positive.

[ryanonthevedder]

First step: Stop what you are doing!

Second step: Install an E12-80 electronic ignition!

I just did the swap with my '73 and it works awsomely!!!

It is a direct bolt on and only requires a small jumper to utilize the stock wiring.

You can find distributors used or new at rock auto and you can select the total advance depending on what year of 280ZX you choose. I am running an '81 w/ 55 degrees advance. It is 8 more than stock but I have a big cam an fully functioning EGR.

Instructions for a later car but has all the important info.

http://atlanticz.ca/zclub/techtips/distributor/index.html

Distributor advance chart

http://www.classiczcars.com/forums/showthread.php?34192-280ZX-Distributor-Advance-Curve-Reference

My points distributor had some kind of very mysterious problem that made me nuts so I got rid of it. My suggestion is to do the same!

[ryanonthevedder]

Also regarding the fuel problem, change the filter in the elec. fuel pump. Yours is probably plugged, as mine was.