I've had my Z since new, it's a 74 260 with manual trans. I drove it for 15 years, then parked it in the garage for the next 15 yrs.( Big mistake) I've spent the past 4yrs getting it running again (lots of work) but a labor of love). Had the head rebuilt, replaced the flat top carbs with older SU's as well as several other parts way too numerous to list. Had it running good but now am experiencing intermittent electrical problem (no spark) which I believe and finally my mechanic agrees is a problem with the Transistor ignition unit. (We've already eliminated a fuel delivery problem as well as the obvious problems, ie. coil, distributer, plug wires, dist cap, wire corrosion, etc.) It's a 5 wire unit marked as E12-05. Could really use some help locating one or another way around it. I've seen on some other sites as well as my mechanic that I could replace it with a Chrysler 5 wire ECM but can't find any information on wiring it. Any help or advice would really be appreciated.

I have 2 E12-5 ignition modules from parted 260Z,s if you want to stay original,or upgrade to an ignition system that is easily found and adapted such as msd, pertronics,crane, 280z E12-80 ,mopar perfomance .......

Here,s the wiring diagram for the mopar ECU http://www.moparts.org/Tech/Archive/elec/3.html

Edited April 25, 200915 yr by beezee

I would think in terms of future failures with that E12-05. Beezee's modules may or may not be the same as yours but new ones are virtually impossible to find and expensive if you do find them. I'd go with E12-80 dist. preferably from a 1979 ZX. The module for those can be replaced with a GM HEI module wihich is inexpensive and plentiful. It takes mimimal electrical skills to accomplish. That Mopar setup looks kind of 'rocket-sciencey' to me.

I have 2 E12-5 ignition modules from parted 260Z,s if you want to stay original,or upgrade to an ignition system that is easily found and adapted such as msd, pertronics,crane, 280z E12-80 ,mopar perfomance .......

Here,s the wiring diagram for the mopar ECU http://www.moparts.org/Tech/Archive/elec/3.html

I would prefer to stick with the original since the car is pretty much stock except for the older carbs which is a major improvement over the flat tops.

Do you know if your modules were working when the cars were parted out?

Thanks for the info on the upgrade.

I would think in terms of future failures with that E12-05. Beezee's modules may or may not be the same as yours but new ones are virtually impossible to find and expensive if you do find them. I'd go with E12-80 dist. preferably from a 1979 ZX. The module for those can be replaced with a GM HEI module wihich is inexpensive and plentiful. It takes mimimal electrical skills to accomplish. That Mopar setup looks kind of 'rocket-sciencey' to me.

Thanks for the input. Beezee's modules are the same if we can rely on the markings and would prefer to plug one in and see if it cures the problem. But if they don't work, are you suggesting that I upgrade by replacing both my distributor as well as the module from a 79 ZX? Or would the E12-80 work with my existing disty?

I've seen on some other sites as well as my mechanic that I could replace it with a Chrysler 5 wire ECM but can't find any information on wiring it. Any help or advice would really be appreciated.

See if this helps:

http://ZHome.com/ZCMnL/tech/ThomasMSD.htm

That was the only "Chrysler" part I could find - many that is what you were thinking about.

FWIW,

Carl B.

Edited April 25, 200915 yr by Carl Beck

Thanks for the input. Beezee's modules are the same if we can rely on the markings and would prefer to plug one in and see if it cures the problem. But if they don't work, are you suggesting that I upgrade by replacing both my distributor as well as the module from a 79 ZX? Or would the E12-80 work with my existing disty?

I did mean the entire swap, distributor and module.

I would prefer to stick with the original since the car is pretty much stock except for the older carbs which is a major improvement over the flat tops.

Do you know if your modules were working when the cars were parted out?

Thanks for the info on the upgrade.

The modules were in a box of parts from 2 parted 74 260z,s.The easiest fix is a drop in E12-80 dizzy . The mopar performance P4120505 ECU and harness P3690152 is available through mopar performance also easily adapted using your original dizzy and wiring. I could send the Hitachi modules if you want to try them, there just collecting dust here.

Gee, there are TWO of us in the world of Z! I am the original owner of a '74 2+2. My ignition unit failed once upon a time but fortunately many years ago when they were available. Good luck! Dave

The modules were in a box of parts from 2 parted 74 260z,s.The easiest fix is a drop in E12-80 dizzy . The mopar performance P4120505 ECU and harness P3690152 is available through mopar performance also easily adapted using your original dizzy and wiring. I could send the Hitachi modules if you want to try them, there just collecting dust here.

I'd like to try them mainly to see if that is indeed the problem, as well as remaining as original as possible. I'm probably 95% sure after eliminating everything else I could think of and before I upgrade to another set up. How do we do the logistics of trying them out?

I did mean the entire swap, distributor and module.

Thanks for the clarification and input.

Gee, there are TWO of us in the world of Z! I am the original owner of a '74 2+2. My ignition unit failed once upon a time but fortunately many years ago when they were available. Good luck! Dave

Thanks, I hope this is it. We both must be attached to our Z's like people are to pets.