1993 Patrol disguised as a Maverick - Engine won't run for more than a few seconds

[Gunman]

G'Day, My first time here and I've come asking for help. I brought a 1993 Patrol disguised as a Maverick in 1997, had it ever since. Converted to dual fuel, a carby TB42 fitted with a Pirana Ignition System. This problem started about 5 months ago - Normal Driving (ND) tacho would bounce around as though a 'loose wire', graduated to complete shutdown (CS) ND, notice that all the gauges drop like a stone. A little time 'down' and start up again. Some times CS during ND, one second and switch back on, continue driving. 2000km return trip to QLD, one small 'hiccup'. Good as gold. Home two days and I cannot get this thing to run for more than a few seconds. Coil has been changed, Pirana Ignition System (couple of smaller plastic items replaced), Earths cleaned up, some small wires and connector repaired. When it was running it was sound, smooth didn't miss a beat.
Any constructive advice would be appreciated.

[threedogs]

Hi mate pop over to the intro first eh polite and all.
Its something the Forum asks of us all before asking a question.

what does it feel like spark or fuel related

[Gunman]

G'Day Threedogs, Yeah, I did look but what am I missing? I can't find the 'intro' so far, but I'll keep looking. OK That's done.

[Gunman]

It 'feels' like electric failure.

[Col.T]

G'day Gunny,
can't help I don't think as I've been a diesel man.
IF you've proven the battery is good, proven you've got a spark, not got any engine fault light (does your wagon have one of those diagnostic systems?) and it fires and runs well for a few seconds, on a mechanical level it may be a fuel related prob>> Maybe?
Have you got anywhere yet?
Col.

[Clunk]

There's been a few members on here that have had issues with running on gas. Parksy for one comes to mind and I'm pretty sure he did a write up. I'll see if I can find it when I get home

[Clunk]

Sorry bud struggling to find the thread, but after a search on "dual fuel issues", it showed up a lot of threads talking about various things that can cause issues, which is way above my level of understanding...... There us a thread done by Pezzer which is interesting but his was an efi

[RubberDuckieGQ]

I have a dual fuel and have had issues with it too
When you can't get it to keep running - is that on gas or on petrol? Or both?
And is it an idling issue i.e. what if you put your foot down or pull the throttle out, can you keep it running then?

Some problems we've had with ours:
Too much air getting to the gas, so had a lever put in that you push in when switch to gas and it pushes a seal 'lid' down to block air
Then it started to run rough on petrol, needed a new carby (previous owner ran it on gas all the time)
Idling was too high/low for petrol/gas (or maybe the other way round) - older engines are difficult to tune to both

[Gunman]

G'day Guys, thank you all for the warm welcome and advice. Ok, it appears to have been the ignition relay in the fuse box. Swapped the 'accessories' and 'ignition' relays and it started faster than normal and runs. Not going to fool myself yet, so far I've found four problems, repaired them and motored on for anything up too six weeks before the fault re- surfaces. I've repaired a minor earth, the A/C earth, the 'Piranha' ignition as well as replaced the coil and ignition switch. Lotta stress but less than $100. I do luv Nissans

[threedogs]

Good the hear you may of found the problem,
wouldn't hurt to run a few new earths as well IMO
May be worth all GQ owners swapping the ignition relay.regardless