Ignition module (E12-80)

Broughton

Club Member
I've searched this site (and other sites too) but cannot find how to test the subject ignition module. Can anyone help?
 

Broughton

Club Member
What car is this for do you mean the black box on the side of the distributor?what are the symptoms?
Car is special using 280ZX engine and yes, the black box. Symptoms ................. engine fires-up on the key for mere second or two then dies.
 

jonbills

Membership Secretary
Site Administrator
Car is special using 280ZX engine and yes, the black box. Symptoms ................. engine fires-up on the key for mere second or two then dies.
second or two, or dies immediately you let it off cranking?
I don't know how yours is wired, but on the original cars, there's a CRANK +ve feed to the coil and a RUN +ve feed to the coil.
If the RUN wire is disconnected, it'll start on the cranking feed, but die immediately you stop cranking.

alternatively, might be worth checking the fuel pressure in the rail - I can imagine ways for it to build enough pressure before cranking, but then be insufficient straight after.
 

Broughton

Club Member
Hi Huw.
The copied pages are most useful (please name the book/ manual so I might obtain a copy). Not only test for ignition unit but for pick-up coil as well. Great!
So, with the ignition unit plugged into the dizzy and 400ohms at the pick-up coil all should be well. I'll test in next couple of days or so and let you know.

Very many thanks.
 

Broughton

Club Member
second or two, or dies immediately you let it off cranking?
I don't know how yours is wired, but on the original cars, there's a CRANK +ve feed to the coil and a RUN +ve feed to the coil.
If the RUN wire is disconnected, it'll start on the cranking feed, but die immediately you stop cranking.

alternatively, might be worth checking the fuel pressure in the rail - I can imagine ways for it to build enough pressure before cranking, but then be insufficient straight after.
Hi Jon.
Thanks for your input. Good stuff!
"Special" in this case means, amongst other things, the fuel injection is replaced by a couple of SU's and the wiring is not Datsun.
Fuel is provided by elect. pump which, for purpose of problem solving the present issue, I've jury rigged to run continuously so there ought not be an issue with fuel supply.
Most irritating because the engine cut out whilst going through MOT and only one more check to complete (brakes) other wise clean bill of health. Examiner had to issue MOT "FAIL".

Cheers
 

Huw

Club Member
Hi Huw.
The copied pages are most useful (please name the book/ manual so I might obtain a copy). Not only test for ignition unit but for pick-up coil as well. Great!
So, with the ignition unit plugged into the dizzy and 400ohms at the pick-up coil all should be well. I'll test in next couple of days or so and let you know.

Very many thanks.
Glad it was helpful. It’s a factory service manual, they tend to crop up on eBay for the different years . Mines a 79.
 

SteveG

Club Member
Probably not useful comment, but I had trouble with an ICM. I accidentally touched the wire to the ICM and the engine cut out. This was quite repeatable. Anyway, I cleaned up the connections and have had no issue since.
 

Broughton

Club Member
Thank you gentlemen for your help but still banging my head on the wall with this one! I replaced the ignition unit with a second hand one but still no joy.

Possibly the original and second hand ones are both faulty, or the problem lays elsewhere. Best way to check my units would be to try them on a known good runner.

Soooo ................................. would any kind soul out there let me try my units on their car? It would only take a few minutes to swap them over and absolutely no harm could be done.
 

Broughton

Club Member
Thanks Huw and Yep!
350 ohm! Datsun bible says approx 400 so I'm taking 350 as OK as there must be continuity.
 

Huw

Club Member
Ok, so I assume no spark at all, have you checked?

Have you checked the obvious culprits coil, leads, rotor and cap?

Is the dizzy shaft actual turning?

You mentioned you have the pump running, it’s not the old EFI pump is it or have you replaced it for one with the correct lower fuel pressure for carbs?

I ask as it’s not clear to me what the symptoms you are experiencing.
 

Broughton

Club Member
Hi Huw.

Symptoms:- Engine runs perfectly for a few seconds ................. then dies!
Plenty of fuel in carbs. Electric fuel pump working perfectly and fuel pressure is regulated for carbs at 3psi by Filter King.
Pulled a lead, put a plug on it and it sparks when earthed. Coil works fine on a different car. Cap and rotor look OK.
Suspecting ignition module but hard to find and expensive to buy just to try and that's why I'd like to try my module on a working engine.

Bit of a teaser.
 

jonbills

Membership Secretary
Site Administrator
and it will repeatedly start but only run for a few secs? you dont have to leave it a bit?
 

Huw

Club Member
Hi Huw.

Symptoms:- Engine runs perfectly for a few seconds ................. then dies!
Plenty of fuel in carbs. Electric fuel pump working perfectly and fuel pressure is regulated for carbs at 3psi by Filter King.
Pulled a lead, put a plug on it and it sparks when earthed. Coil works fine on a different car. Cap and rotor look OK.
Suspecting ignition module but hard to find and expensive to buy just to try and that's why I'd like to try my module on a working engine.

Bit of a teaser.
Mmm I’d say it’s a teaser. Those modules tend to just fail not fade away. You get rough running, misfires and low power on acceleration. Could be duff but it should still run, just not very well.

Im not a carb expert so not sure what’s going on there, difficult to fault find if you’re not there 😞 Maybe fuel starvation?
 
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