Drove fine to work now won't start.

[johnnyddn]

The car is a 1978 280Z with a 280zx dizzy installed. So I drove my car to work which is 25 miles away it and drove absolutely fine to work. On my lunch break, it started fine and drove. After eating, went out and tried to start the car but it wouldn't start right away. After about 10 mins of cranking it fried up and drove it back to work. After work came out and cranked it all night till the battery died and it wouldn't start.

Checked the plugs and they looked good. Went to autozone bought a new rotor and distributor cap, still doesn't start. I hooked up a spark plug straight to the coil and to see if the coil is good. I noticed it sparks when I put the key on ON, but no spark during cranking. I also have notice that sometimes when I turn the key to crank it won't crank sometimes and I have to twist the key back and forth until it cranks. Would the ignition switch cause the car not to have spark during cranking?

Edited January 19, 2011 by johnnyddn

[beermanpete]

It sounds like an igniton problem. Look at the points (if you have points) to make sure they are opening and closing. A bad condensor could also cause this type of problem. If you haven an electronic ignition then it might be the module.

[johnnyddn]

Ok, I do have a 280zx Dizzy with the electronic module. So a bad electronic module can cause the problem of no spark during cranking?

Edited January 19, 2011 by johnnyddn

[beermanpete]

Yes. A bad module will cause a no-spark condition during cranking or any other time.

[EScanlon]

Yes.

The G/W wire at the ignition switch is what provides power to the coil during the Start cycle, and it's the B/W wire that then provides it in the RUN position.

If the G/W wire at the switch is not connected properly it won't provide power to the coil via the tach. However, it should be noted that the B/W wire (in the RUN) position actually connects to the wiring going to the tach and hence the coil.

Since you mention that it doesn't have spark while cranking, but it DOES have it in the RUN position, it points to the resistor being ok, but not the connection from the switch to the join of the two wires.

FWIW

E

[johnnyddn]

Ok, so I went to Autozone and bought another ignition switch. Tried that still doesn't start. Went back to Autozone, purchased a GM HEI ignition module, actually a Duralast DR100.

http://www.autozone.com/autozone/parts/Duralast-Ignition-Control-Module?itemIdentifier=115808

I removed the E12-80 ignition module and wired up the GM HEI according to this.

W - Connects to the positive lead at the distributor.

G - Connects to the negative lead at the distributor.

C - Connects to the negative side of the coil.

B - Connects to the positive side of the coil.

Still no luck. I really thought this was gonna fix it. Would a bad ecu cause this problem or the ECU has nothing to do with Spark? Also does the GM HEI need to be grounded? because I had it just dangling to test if it was working.

Edited January 20, 2011 by johnnyddn

[Carl Beck]

............. it points to the resistor being ok, but not the connection from the switch to the join of the two wires.

E: - - Specifically "where" do the two wires join together?

Carl B.

[ezzzzzzz]

You need to look at a wiring schematic (I'm downloading a 280Z manual from www.carfiche.com right now). Exactly how are you seeing the spark plug spark in the run position with the engine off??? Have you checked for spark while cranking over the engine? Do you even have fuel pressure? The ignition modules do go bad BUT a hit/miss symptom is usually heat related. If the car sat for a few hours and refused to start if could be loss of fuel pressure too. Do you have access to a spare ignition switch? The harness can be unplugged from the mechanical/switch on the column and plugged into another switch to test. Just use a flat screwdriver to rotate the switch to start/run.

Have you tried putting the key into the run position and using a remote switch to turn over the starter?

Note, the fuel pump dies when the engine shuts off even if the key is in the "run" position because there is no air flow thru the AFM to trigger the internal fuel pump switch. BUT when cranking the engine over enough air should be pulled in the turn that fuel pump switch "on".

Edited January 20, 2011 by ezzzzzzz

[EScanlon]

I stand corrected, I was basing my wiring help on the 240 circuitry.

While the 77 and 78 have similarities, both of them have numerous connections to the wires from the ignition switch to the coil.

Trying to ascertain a specific connection's likelihood of failure based on that, (which is what I originally intended to do) is now too complex for quick analysis. The 240's circuitry only has a few connections in that circuit. The 77 and 78 have several additional relays all part of the ignition circuit.

FWIW

E

[Zed Head]

Still no luck. I really thought this was gonna fix it. Would a bad ecu cause this problem or the ECU has nothing to do with Spark? Also does the GM HEI need to be grounded? because I had it just dangling to test if it was working.

Your symptoms don't really indicate a bad ignition module.

But, regarding the HEI module that you installed, yes, you do have to ground the case of the module for it to work correctly. A grounding lug is molded in to one of the mounting holes. It is well-documented in all of the installation instructions (surprising that missed it, hope it didn't do any damage) that you have to ground through one of the mounting holes. Some people even run a separate ground wire from the mounting hole.

From what I've read (I have one on my car but it has always been grounded, so can't say for sure) they will be damaged internally if they lose electrical ground.

Might be worth grounding it and trying again. The critical mounting hole has a wide flat grounding area, it's easy to see.

Edit - If you have a voltmeter, check for battery voltage at the coil terminal, both sides, when the key is on and when cranking.

Also, the magnets under the stator plate can break on the 280ZX distributors. Connect a voltmeter to your positive red wire from the distributor and see if it is generating the voltage pulse necessary to fire the module, while cranking,

Edited January 20, 2011 by Zed Head

[FastWoman]

In answer to one of your questions, the ECU has nothing to do with delivering spark. Rather, a signal off of the ignition feeds to the #1 ECU terminal and clocks the fuel injection. It's possible for an inoperable IM to result in an ECU not delivering fuel, but it's not possible for an inoperable ECU to result in loss of spark.

[johnnyddn]

I just wanted to say thanks for the help everyone! I put in another 280zx dizzy i ordered from a junk yard and it fired right up.