HEI Upgrade not working on '78 280Z

[bullitt01]

I forgot to put in my last post that last night I realized I had the red wire and ground wire on my HEI module mixed up. I put them in the correct spots and it started and ran for a couple minutes and then just shut off. Also, now when I try and crank the motor the starter motor will no longer engage the flywheel. It just spins but doesn't turn the motor. Could the starter issue be related or just coincidence? Think I fried the HEI or coil by hooking it up wrong?

[Zed Head]

It sounds like you're saying that after it started and ran, then died, that after that it never started again, and that now when you turn the key to Start, you hear a noise from the starter that sounds like it's spinning.  When you turn the key to Start and hold it do you hear a spinning noise, constantly?  Or does it make a nasty noise, you let go of the key, and it makes a spinning noise?  I'm thinking that your battery might need a charge.

 

Check voltage on the battery and make sure it has a full charge.  You can get misdirected when the odd things happen.  Voltage should be 12.6 or higher.

[bullitt01]

Thanks for the input on the coil heating up. I'll try and figure out what's grounding it. If that is the case it seems wired that it ran fine for a couple minutes.

When I turn the key the starter motor now it spins but does not move to engage the flywheel. If I hold down the key the starter motor just spins and spins. Battery voltage was 11.8V. That should be enough to properly operate the starter but I'll throw the charger on it and see if topping it off changes anything.

[Zed Head]

12.2 volts is ~ 50% charge.  11.8 is essentially dead.  Get a good charge, start over and see where things are.  12.6 or higher is about full charge.

[bullitt01]

I put the battery on the charger to top it off. It's at 12.9V now. The starter still won't stay engaged with the flywheel. When cranking the starter is getting full voltage to the motor but only 9.8V to the small wire that goes the the solenoid. Not sure if that's low enough to cause a problem, but I'll try and trace it back and see if I can find any problems along the way. Maybe the solenoid just finally quit and it's just coincidence that it happened in conjunction with my other issues.

[EuroDat]

I would say 9.8 volts was normal if it was cranking the engine. Sinse the starter is free wheeling, the battery is not under any high load so battery voltage will be a lot higher.

The solenoid will need full power the push the starter pinion into the flywheel ringgear. Once its in position the lower voltage while cranking will be enough to hold it there. I think this is your starter problem.

From your description it seems like resistance in the wiring to the solenoid. It could be a result of the crossed wire in the HEI setup where the ground and battery wires were switched.

The HEI and starter solenoid come from the ignition switch, so I would start checking between the battery and the ignition switch. It could be a fusable link or a bad contact in the ignition switch.

[Zed Head]

The starter still won't stay engaged with the flywheel.

I had a 78 parts car that had a similar problem.  I'd get click-whir, click-whir until it finally grabbed and would start the engine.  When I finally took it apart I found chipped starter teeth.  I don't know if they were the cause or a result, but I have that engine and flywheel in my car now with a different starter and no problems.

 

If you want to test the starter solenoid wiring, make sure the transmission is in neutral, take a screwdriver or wrench, and touch it to the main lug on the starter (where the battery cable connects) and the small male connection on the solenoid.  That will provide full power directly from the battery through the tool to the solenoid.  If the car is in gear it will jump forward so be careful.  

 

I also had a starter begin to fall apart.  The bushing in the nose had worked its way out of its seat.  That starter made a terrible noise sometimes after starting as the shaft wobbled around.  I imagine that it if it had broken or came all the way out, the shaft could have got misaligned and caused worse problems.  The starter has a mechanical lever and pivot action from the solenoid to the gear drive.  Could be that it just broke.

[esh]

I have a similar problem, I installed a 4 pin gm hei with stock 78z coil. with 5 spark plugs removed from engine the installation will fire the installed plug as the distributor rotates.

when I install the remaining 5 spark plugs, the hei will not fire any plug.

I have a new distributor pickup coil, with 700 ohm resistance and generating a small ac voltage ( 2 vac or less).

the coil primary resistance is 1.0 ohm.

thank you in advance for help/ comments

 

[Zed Head]

Sounds like you have low voltage, or low current through the module.  With 5 plugs out there's less load on the starter and more voltage for the module during cranking.  You didn't answer the questions in the thread, about wiring or battery voltage.  Could be a poor battery, or a poor ground through the module mounting points.  The 4 pin modules are actually 5 contact devices.

[esh]

thanks

battery terminal voltage  is 12.88 volts , coil positive terminal is same voltage with ignition switch on, starter not engaged.

I wired the hei as per your previous post. I mounted on metal plate attached to the coil mounting bolt, using the supplied grease.

I grounded the plate and the module separately to the ground for the afm. resistance readings to ground indicate very low or no resistance.

I did unplug this upgrade hei and plug in my oem module and my car cranks and runs fine.The oem module was unplugged during the attempt with the hei module .

i  also rechecked ignition coil resistance and it is 1.5 ohms on the oem coil.

I will reconfigure and measure coil voltage under starter load current draw with the hei module connected.

my concern is possible coil saturation due to higher resistance primary coil winding, or my reluctor and pickup coil are not generating an adequate threshold voltage to trigger the hei module.

[Zed Head]

I've mentioned this before, but I damaged a module once by leaving two spark plugs disconnected after doing some work on the engine.  Started the car, it ran poorly, I realized what I'd done, shut it off and reconnected the two plugs.  But the module only put out a weak orange spark after that.  It would start with starting fluid but not by the normal method.  Replaced the module and everything was good.  I don't know what exactly damaged it, maybe a stray spark, but it was ruined.

Short answer - maybe you have a bad module.  Did you do anything that might have damaged it?  Incorrect wiring, even for a moment might do it.  If you got the module from a parts store, they might exchange it and you'll be good to go.

Also, I believe that you can get the module to spark by itself by applying battery power to the W terminal and grounding G.  Each tap of battery power should cause a spark.  But you've already shown that the distributor is doing its job, and you're getting spark with one plug.  Is it a strong blue spark, or a weak yellow/orange?

The 78 module is actually a high-energy system.  No real benefit to the HEI unless you're just getting ahead of its eventual failure.

[esh]

I used an inline spark tester on number 5 plug and it appeared to generate a good strong spark.

yes I am preparing for the failure of the oem module.

I will test the module as your post stated. I bought it online  inexpensively.

thanks for the help.