Offroad-Express

Gents, I’m at the end of my knowledge and Google results.........G16A 16v.
I’m trying to help a farmer fiend get his Zuni running after he turned it off one day and the next time it just cranked and does not fire up.
Currently there is a fat spark as one starts the crank, then zero during the crank and again a spark as on let’s got of the key.
Now this tells me some thing (hall sender unit in dizzy) is faulty and not telling the ECU it’s tryign to run so doesn’t send a signal to the coil.?
I have done the following:
Brand new battery
Replaced all battery to engine and body earths, add additional earths as well.
Stripped the starter and machined it down and cleaned it in case it drawing too much current and robbing the power
Tried three coils and ignition modules
Tried three ECUs
Tried three dizzy
Two different throttle position sensors.
Two came out of running zuks and were put back and they fired right up.
I checked then replaced every fuse
I dropped the fuse box and check the wiring for rat bites etc , no corrosion and all circuits are complete. The single big fuse is also fine.
When I bridge the OBD1 plug is faults 42.........42 is crank angle sensor which is the hall sender unit in the dizzy as it doesn’t have a seperate sensor. But I have replaced the dizzy 3 times with runners. It’s a 2 wire dizzy and the power goes in and out to the ECU.
I even replaced the ballast resistor with two other, no spark while cranking.
I’m not out of smarts................any gurus that know Zukis that can help please.

Have you tried bypassing the key barrel ?
Key start signal to the ECU might be intermittent .
I would also be checking he engine wiring harness for shorts to ground .

Hey thanks for that info...............I forgot to add that I even changed the ignition switch over from a running Zuk haha oh man this thing is driving me nuts. Time for a carb..................................

is it an auto trans?

Yer auto, i wiggled the lever just in case there is a bad connection.

My guess was an issue powering the coil while cranking but I did not think they had ballast resistors still . Alas you say you swapped it out .
I would say put a light or multimeter on the positive on the coil and see if you have light/voltage with ign on and then with starter cranking .
If it drops off while cranking its the positive feed to the coil while cranking not the ballast resistor side .

None of that would explain the code thou , unleas the sensor is powered from the same feed .


Cheers
Chris

Yay great news, I opened the ECU and measured each of the capacitors that I could find and one was leaking despite not being swollen or bulging.......$0.80 later from Jaycar it fired right up. Super happy to hand this back to a friend on a farm at Mapiu for his wife to use a farm truck. Thanks for all the help and advice/ suggestions. I have learnt a bit more as well which is great to help other out.
Merry Xmas!