Had a dodgey spark, no wont start..

[Chopz]

Hi all,

Having a problem with my 1992 GU patrol 4.1 efi,

It was shorting out from the dizz somewhere, I could hear a snap' when trying to start it, assumed it was a short in the wiring.. Just started one day. It would still crank.

Then I had a little poke around, checked the wires and connectors, checked basic fuses and stuff ... ... and now she wont even crank over.
I hot wired the starter solenoid and gave it 12v from batt and it does crank. But will not crank from turning the key in the barrel.

Have traced a fat white wire from starter soleniod switch back to main engine fuse box, but cant find it going from there to the key barrel..

I hate it when i try to fix one thing and the next shows it head...

Any ideas guys?

Full battery
All fuses good
All engine fuses good
all lights come on on dash
the key turns on the ignition, but will not crank

[mudnut]

Hello and welcome to the forum. Hopefully someone with a 4.2 can point you in the right direction. Have you checked that the connections at the battery are tight and clean?

[dom14]

Well...... it's GQ to start with, not a GU.

If I follow your description carefully, the next thing I would do is to grab a GQ 4.2 starter circuit diagram(which is available here for free or anywhere in the internet) and test the power to/from the relevant wire to the ignition key barrel.
That way you can rule out or in the whether the issue is with the ignition key or not.
Then you can start tracing the problem from the relevant ignition trigger wire from the key barrel.
You need a 12V globe tester or multimeter, of course.

[threedogs]

Don't the GQ petrols need a longer rotor button and coil for better spark????

EDIT:: might be time to redo some earth straps as well??

[dom14]

Don't the GQ petrols need a longer rotor button and coil for better spark????

EDIT:: might be time to redo some earth straps as well??

Dunno. Mine's an RB30. I've never moded the rotor button. I think it's different on carby TB42, which might be able
to benefit from that mod.

[garett]

have you checked to see if it gets power to the solenoid on the starter ?

if no check the back of the key barrel to see if it sends power out to the solenoid.
if yes you probably have a break in the wire...

[dom14]

From the description, I think his starter is ok, but the power is not reaching it from the ignition switch.
I reckon it's a faulty ignition barrel to start with, or connection failure near there.

Mine did something similar last year, and it fixed itself after I was playing with the back of the key barrel.