Jump to content

280zxt engine harness question

Recommended Posts

Long story short... Have Megasquirt, hate it (was installed incorrectly harness so molested at this point that its depressing), want to go OEM or as close as possible.  



1971 240z everything is stock 240z besides the engine.

GM hei ignition

1981 280zxt engine


Currently on engine:

external '81 Distributor

megasquirt ECU/kwik wire harness

'81 280zxt injectors




I want to remove the MS ECU and associated wire harness, Have a 1983 280zxt Engine harness/ECU/Distributor (10notch on spindle).

Can i remove the MS EC/ Kwik engine harness, using it as a guide for wiring the '83 harness and retain my '81 distributor?  Or do I need to modify anything and use the '83 Distributor?


Thanks for any help

Link to post
Share on other sites

I'm going to say buying a $65 harness and getting rid of your 81 CAS will solve whatever problem they were having with the MS.


There is ABSOLUTELY no reason to change to an 82/83 CAS to use the latest harness, the stock harness, like any other using the 81-83 CAS is irrespective of the CAS used, they both put out EXACTLY the same signal, hook up to the EXACT same connection on the harness.



But again, I would change to the 83 CAS module (you are calling it a 'distributor', it's not, it's the CAS. On the 81 it's a "Distributor" -- on the 82/83 it is the CAS)...


My bet is for the cost of a new harness ($ Cheap) and putting in a functioning 83CAS all the problems they were experiencing with the MS using the 81 CAS will go away.


The drivability of even a poorly calibrated MS is night and day better than any stock 81-83 ECCS System.

Link to post
Share on other sites

I believe I have the GM HEI Ignition(?) I will have to double check.  I'll print out the wiring guide, but if the block is from an '81 and the CAS (Thank you for the correction) is from an '83 will i have to replace any of the internals to accept the new CAS?  On a previous thread I read it said this might be the case, but i'm failing to find that specific thread again.  


Again, thank you for responding.

Edited by TheDeadZed
Link to post
Share on other sites

Nope, the 81 CAS on the crankshaft, is 100% compatible with the 82/83 CAS in the Dissy, the ECU doesn't care. The waveform output to MS is IDENTICAL.


Trust me on this one, I was down to Oscilloscope testing of the waveforms...a case of Moosehead, and one Flying Beckman 100ms O-Scope later I came to the realisation that the 81 CAS I STARTED with was good, but FAILED once warm (probably why the car was in the JY...) and that the damned Comm Chip in my laptop was bad, and corrupting my MS files when I hooked up to it to do fueling tweaks.


Fixed it by putting an 83 CAS on it, plugging it in, and using a new laptop.... since then, running FAMOUSLY!  

Link to post
Share on other sites

Correct.  You can't just replace an '81 distributor with an '82-'83 distributor.  You also need the distributor shaft from the '82-'83...  Welcome to the wonderful world of dropping the oil pump and properly installing the shaft that drives the pump and distributor.  Hint: know everything there is to know about this before you start.  Installing the shaft improperly will cause you enormous headaches.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...