1977 280z with MSII no voltage at coil

[ZDrummerGuy]

Hello,

Me and my dad just recently installed a MSII V3.0 into a 280z and have been having trouble getting the car to run properly. It will idle rough, bog when revving, stall for no reason..etc.. We've done everything in TunerStudio to try and make the car run at least decent. But, rich or lean with extreme advance or retarded in spark makes no difference. So we've come to the conclusion that the original electrics on the car are the problem. The fuel pressure is at a solid 30psi and through numerous tests of the injectors, we know they all work no problem. Testing the connectors going to the injectors shows that they're all fine too. It all comes down to the ignition system. I've been going through the 280 EFI bible and looking through the trouble shooting part and so far I've come up empty handed. Doing some volt meter tests on the car show that the coil is now not getting any relative voltage at all... even though it is brand new... looking back through the electrics on the passenger side of the car where the sea of wires live, I know that connector C3 would hold the connection between the coil and wherever in the ignition it goes. The connector was fine and I tried to follow the connection back further but got lost so I need someone to tell me what I should look for to determine what's causing this issue. And if anyone knows what else might be causing the car to act so strange please leave a response. It was acting like this when the coil worked too. Thanks!

[SteveJ]

Doing some volt meter tests on the car show that the coil is now not getting any relative voltage at all... even though it is brand new... looking back through the electrics on the passenger side of the car where the sea of wires live, I know that connector C3 would hold the connection between the coil and wherever in the ignition it goes. The connector was fine and I tried to follow the connection back further but got lost so I need someone to tell me what I should look for to determine what's causing this issue. And if anyone knows what else might be causing the car to act so strange please leave a response. It was acting like this when the coil worked too. Thanks!

What are you using for your ignition? Are you using the stock TIU? If there is nothing to change the state of the field in the coil, you won't see potential because you're just measuring across a wire, not a load.

If you want to see if you have voltage at the coil,

1. Disconnect the positive wire from the coil.

2. While holding the positive wire away from the chassis or any other grounded parts, have someone put the key into the ON position.

3. Measure the voltage from the positive wire to the chassis ground.

You should get around 9 volts if you still have the ballast resistor in the circuit.

Check your rotor, distributor cap, and ignition.

This may help you in your quest, as well: Test Your Ignition System - Randy's Repair Shop