GQ trouble starting / bogs down on petrol ??

hi guys i have a couple of very frustrating problems with my petrol/gas GQ. The first problem is it wont start on gas hot or cold, the previous owner said to change the plugs from bpr5es to bpr6es, because to start it on gas i needed hotter plugs, well ive changed the plugs to bpr6es, and it still wont start properly on gas. I think i may have seen a slight improvement starting on petrol but it hasnt fixed the gas start up atall. I went to see a mechanic who was recommend to me, hes had GQs most his life and so has his other mechanic so im pretty confident i have a good mechanic hes a great fella too, very helpful. He showed me, turning the ignition on 3-4 times before starting it will release more gas to start it, and this works probably 50% of the time, but if this doesnt work the first attempt then it wont atall i have to go on to petrol start it then flick to gas and run the petrol out. So common sense tells me (because im no good with engines ect) one ignition turn isnt releasing enough gas to start it right up, what do i need to do to fix this ?

my second problem is when im on petrol, if i put my foot down and im climbing even a slight incline it will bog itself down try to come back but then it will just cut out in while driving, ive got a new fuel filter to replace it, but the filter isnt in its normal position so i have to find that too, it also has an electric fuel pump which ive been told could have some crap in there. Basically it feels like when i put my foot down on an incline its not giving itself enough petrol to keep up so it cuts out comes back abit maybe, then it will cut out.

if anyone can help me with these problems it would be much appreciated.Iim getting real frustrated now

what type of prime system does the gas have , some give a small squirt of gas when you turn the key.
turning it on/off twice does this help? ok just read the lot.
I think you need to give the system a birthday. put a kit through the converter, new air cleaner
etc. 99% of gas problems are electrical. but you may be staving for gas does it back fire at all??
It will bog down on fuel because the carbie is dry from lack of use and the accellerator pump in
the carby is dry also

Need more info mate...
Is it Carby or EFI?
Is it timed for gas or petty?
How often is it run on Petty?
Does it have an extended rotor button and/or hi-performance plug leads and/or have an aftermarket ignition etc?
Does your system start on LPG if selected or does it use petty to start and switch to teh selected fuel when it runs?

what gap are you using on the spark plugs ? what gas system you running ? how many km on the engine?

hi guys thanks for the replies, my GQ is carby, but im not sure what its timed for, it runs better on gas, but is faster on petrol, its only driven on petrol 2-4 times a week, which is only when i cant switch it from petrol to gas after starting it on petrol, this has happened a few times now, so il drive on petrol hoping it wont starve itself when my foots down either for a little but or if im on an incline, but its almost always does cut out eventually.

Im not sure what an extended rotor button is but if you describe it i can have a look, it does have bosch leads on which the mechanic pointed out as an upgrade,and it does have and aftermarket electric ignition but im not sure which one/brand. It is suppose to start on LPG when selected, but wont ever start one first full turn it has to be prompted with 3-4 ignition turns first. Im sure it doesn't use petrol initially then switch to gas, but maybe this is a good option ?

Im using 0.8mm ive followed the gap they were pretty much at, which was the same as the BPR5es that came out, and the mechanic said id would be good with what they were already set at. its never back fired.

I have found something out today, after i put 40L of gas in it started every time right up after 3-4 ignition turns, and was pokie as on the road. last night o the way home it drove like s!@t, it was restricted in the revs and couldn't drive past 65-70, i dint thing i was out of gas because my trip said 300k and ive been getting around 400k, but after fueling up today obviously i was

Bump for Baloo as his last post went into moderation

Go over the gas connections with some soapy water,
can you smell gas at any time???

what Gas system is in your Patrol

what year is your Patrol

what Motor is in your Patrol

these things will help people like ET, to help you diagnose what the problems are.


as a "for instance" my old GQ with a TB42 - I had faster off line speed in petrol, but I could spin 11R tyres on a dry bitumen road..........

if you can take a picture of the engine bay
and post it up

some one may be able to recognize the system etc

and give you some hints to look at

i have smelt gas briefly before threedogs, but im sure it was just after i started it.

im not sure what gas system is on it, but its a 1990 GQ 4.2 petrol/gas. Ye il have to take a picture, cheers

ok,
there is 3 main types of gas systems
it could be - and usually is a mixture of the Gas Converters

OMVL Converter
Attachment 62747

Impco Converter
Attachment 62748

and one similar to this from Vialle (this is a Ford one)
Attachment 62749

then you have the Mixer - on top of the Carby


Gas Ring type - (crap crap crap)
Attachment 62751Attachment 62752

Impco 300
Attachment 62750

Sprint Gas type
Attachment 62753

all have pro's and Con's - except the ring type mixer - its just crap...............

thanks for the pics bigcol, il have a look around find out which system i have, been underneath to look for an inline fuel filter but still cant spot one, decided im going to take it to the mechanic tho, to see about the petrol problem, it keeps starving its self

I had that sprint gas mixer on my 350 chev , trouble with them on a 4 barrel is the only get gas to the primary
jets/bore and the air filter is open , so creek crossings and bog holes need extra care. looked neat though

I start my gq all the time on LPG,

I turn the ignition run, wait until I hear the LPG solnoid drop out (about 3 seconds). I then crank - it starts every time.

I have a ring mixer.

Re- drove like s!@t, it was restricted in the revs and couldn't drive past 65-70, = out of lpg (i'm getting around 330km per tank)

Plug gap for lpg needs to be about .2mm smaller than std.
Lpg "can" be very dirty with a black sludge that can block up the converter.
its something to do with how clean the fuel is manufactured or rather.

Guessing the mixer has a fault, split rubber diaphragm.
and carby is due for a kit from age, and running lpg.

by the sounds of it timing is advanced as you recon it goes much better on petrol.
good indication of more advance on petrol, heaps of pull of the mark and less top end power.

Check vacum lines for breaks ( 1 @ a time) Arrrh- this one goes back where?.
check a schematic of the vac lines in the manual against what you have,
previous maintance etc may have swapped em around by mistake.

There is also a small vac cyl , rocker cover side behind the choke assembly.
It has a small shaft that can brake, and this cause issues.
Is available as a s/part but you need a repair manual to reset new one correctly,
it's not just a matter of remove and replace it.
and you may as well, carby rebuild time if this vac cyl is broken.

I had a few problems like you describe, not all at once, but after--
converter kit,
carby kit,
vac lines replaced,
guality plugs, gap little fiddling to find what works best with your mtr.
Good leads,
electronic ign.
it ran like a dream. especially for dual fuel.
I ran iridum plugs they handle the heat way better than normal plugs.
last much longer as a result, but WAY more expensive.
lpg needs a few deg more advance to run and start correctly, so tuning is a compromise for dual fuel.
the rotor ext is a must do for duel fuel.