4.2 petrol-gas ,DA/GQ Mav, Patrol, starts but wont run

[junior96]

hey,

dad bought this car a couple of weeks ago and it runs fine on gas. switch it over to petrol and it wont even start. we changed the fuel filtrer and the oils too. he put about 40lt in it and nothing, the only way we can get it to start on petrol is by tipping somedown the carby. then it will run for about 5 seconds and dies. the fuel pump is pumping and everything looks ok but it just wont go. Any one help us with this problem ??







cheers/ jesse

[dibbo]

if you are getting fuel to the carby then it must be a carby problem it will need to be rebuilt

[junior96]

thanks mate, its not a carby problem(still might be though) but we are thinking that the feul can not get from the long range tank up to the pump. we have been trying for a couple of hourss and nothing. we used the air compressor to push the fuel up to the filter and the filter still was dry...?? now what??

[Swerve]

Disconnect the fuel line from behind the fuel pump, use a clear fuel line and try and start her, you should see the petrol start moving etc ? if not you know it is either the fuel solinoid or fuel pump etc. I was doing this today so is all fresh in my mind

PS- This was easist from the exit of the fuel filter. extend this line to your new fuel source

[1997nissanpatrol]

thanks for your reply,mav has a long range tank,drain old fuel out (4 year old) put fresh fuel in half tank,has fuel punp after fuel filter,need to know if the long range tank has a punp on it,wont self prim. thanks,

[nerida67]

Any old fuel,MUST be removed
If your not getting fuel from the tank,its blocked lines ect
Without knowing all the facts here
You need to start at the back and work forward
IE
Fuel lines ,fuel filters (not worth much just replace them)
Is fuel getting to the pump ???
Is the pump working properly
Is fuel getting up to carby,just take fuel line out of carb and check
IF you are getting fuel from tank up to carb , then still wont go
There mite be little filter inside carb,
IF they clog up ,it will never start
Process of illimination i afraid

This is the problem with LPG/petrol combos
LPG hides all the proplems with petrol

[1997nissanpatrol]

thanks for the reply,fuel line seems to be free blown air through the line bubbling in the tank.Maybe not enough fuel for it to pick up maybe,note the fuel pump is after the fuel filter,what ive got is the steel fuel line coming up into engine bay then into the filter,then into the fuel pump,then into the carby,this is how i bought the car,sorting it out,old fuel filter was dry as a bone.Thanks.

[1997nissanpatrol]

Gday there Swerve,nearly got the mav started tonight(before the footy started go qld).Used the pump to prime the fuel line then hooked the pump up the right way,then found a leak on the pump so put the truck to bed, may get too work on it before work tommorrow.Read your story on your mav sounds like you are winning aswell good luck.Chris.

[Swerve]

At one stage trying to get mine running I wasnt sure I was getting fuel to the carbie, hence why i installed a new fuel source. As they say process of elimination.

When you try and start her ? what exactly is happening ? if you remove the spark plugs, such a bitch on this engine :( are you getting fuel come out ? and have you got spark etc. But I reckon check your timing as well, also is vacum advance connected and working on the dizzy ?

[1997nissanpatrol]

hey everybody,

we found out the pump is now leaking, we can get fuel up to the pump and then the pump leaks, wether we can just get anew seals or have to get a whole new on is unknown yet.







cheers, chris

[1997nissanpatrol]

got a new fuel pump, just gotta install it

ssee what happens

[BadMav]

Did you check the fuel cut off switch? It'll be switched off via your gas system's dash switch. Just trace the fuel line back from the engine, mine is bolted to the battery tray. The trigger wire may have just been knocked off it or it may just have a bad earth??? Also check the cut off solenoid on the carbie. I've heard about people having dramas with it too.

[1997nissanpatrol]

Gday badmav,do you have petrol/gas system aswell,runs well on gas but found out it hasnt run on petrol for a long time,drained old fuel put new fuel in still cant get the mav to run,used old pump to prime fuel line but still wont pick up. mav has long range fuel tank aswell,must serch brand to see if they have a pump on top of there tank. what else can i try.cheers chris.

[BadMav]

Yeah Chris, mine is dual fuel too. Have you tried purging compressed air back down the fuel line to the tank? The pick up may have been clogged up with some crud. Another thing I'd try, it sounds a bit "backyard", but if you've got a boat fuel tank or can borrow one, try hooking your fuel line to it and see if you can get it to run off that, that way you can be sure it's the tank without pulling it out.

If it will run off the boat tank & you've purged compressed air to the mav's tank and it still won't prime then my guess is the pick up may have come adrift and the tank will have to come out.

Rowen

[1997nissanpatrol]

Gday badmav,have used compressed air down the fuel line from below the filter(fuel line to the tank heard it bubbling,line is clear,then hooked up pump to prime the fuel line,(pump is located at the bottom of battery tray on the carby side of the filter (existing pump located here).think new filter is full of rubbish out of fuel line,what brand and part no filter do you use,ryco$29.00.cheers chris.p.s paid $2500 has long range tank,rear air locker (old arb)steel rear bar and is petrol/gas.

[BadMav]

Yeah Chris, I don't know what brand mine is as the label is long gone, but it looks like a ryco. That's what I'll replace it with anyway when I do the filters in it.

Can you get the pump to prime fuel at all? I mean like into a bucket? If you can, the next thing I'd check would be the solenoid on the carby. You'll see a wire going to it at the back drivers side, unscrew it and inspect it. Check for any build up on the needle and the seat (if you can get a mirror in there to see), or remove the needle altogether and screw it back in. Try to start it then. Failing that you may have to remove the carby and rebuild it or exchange it.

Rowen

[1997nissanpatrol]

Gday Rowen,no intest in the truck today,day of rest,when i pour fuel down the throat of the carby it runs,just problems getting line primed again,tank has 3/4 of fuel i wonder if tank has enough in it to pull through to the filter before the pump,cheers chris.

[BadMav]

Double check all joints and tighten any hose clamps. A pump can suck air better than liquid.

Rowen

[1997nissanpatrol]

gday Rowen,where abouts are you from,i live in ipswich,must start getting ready for second round of oppsite lock comp this weekend at Janowen Hills 4wd park,might do abit more on the mav during the week would like to get it going on fuel.did you do any wheeling on the weekend.cheers chris.

[BadMav]

Up in Gladstone mate, sorry can't come round to help!