New z owner. Need some help with ignition cutting out.

[Qlynxer]

Ok going to make it quick and to the point.

Purchased 72 240z with original engine and 280 dizzy and msd coil. Car ran good but would randomly shut off. No sputter just instant 0 rpm. Pull over and usually would start again within 1-5 min.

Took to z shop, tech re wired coil. Previous owner had left ballast resistor and mechanic said that it coulda caused problems.

Mechanic gave me a stock 280 coil and said it was more reliable.

Car ran fine for a day then same problem. I swapped over to the 280 coil but still same thing.

Read and read. Found out e12 80 module might be problem. Swapped over to a gm lx 301 type module.

Fired up car and now won't start at all. Switched back to the e12 80 but now won't start. Changed back to msd coil and nothing.

Any ideas? What should i do now? Carbs were tuned up when in shop. Im getting no

Spark when I pull the spark plug wire that goes frm coil to dizzy.

Hate my first post to be all problems but I have read and searched and need some help please.

Thanks Quan.

[Qlynxer]

Another question. I attached an aluminum mounting plate on the gm module but haven't mounted the plate onto anything, just kinda dangling around. Does this thing need to be mounted and grounded?

[ZCurves]

I have a '78, but I'll throw a few suggestions to you anyway. First, I would get my hands on a Factory Service Manual (FSM) for a 72 240. Look in the Downloads section first, then search for the FSM.

When you are new to a particular car AND have a lot of complications, it is best to go back to the original setup. I would remove the MSD and GM equipment and revert back to the OEM setup and then begin to test each component and eliminate each variable. This will help you to diagnose the problem rather than throw time and money at it and hope the problem will go away. You have to get to know your new friend.

Is it correct that you bought the Z with the 280 Distributor already installed by the PO?? It sounds to me like something is shorting out, have you tested the distributor? Is the coil good? What about the Ignition Module? Is the wiring correct and complete?

There have been many Series 1 guys here that have performed the Distributor conversion w/Electronic Ignition. Search the threads and see if there is something there that will help. I am hoping that some of the 240z members will speak up.

Good Luck

Edited April 22, 2011 by ZCurves

[Zed Head]

The GM 4 pin module has to be electrically grounded through one of the mounting holes to function. I have read that they can be damaged if they lose ground, so yours may be damaged if you tried it without. Some people (me for one) run a dedicated ground wire from the mounting hole to make sure they have a good connection. The heat sink and the ground serve two different functions.