air in fuel

[ox 123]

I have air going into the fuel filter and it is worse if it is parked facing up hill I have to prime it on first start up but will run all day. I have replaced filters, lines checked all clamps this even has mechanic stumped let me know if anyone has had the same problem and how to fix it, its driving me insane trying to find the problem.

[threedogs]

Maybe fuel lines have perished, replace engine bay
ones only 30cents a mtr for 4mm stuff

[ox 123]

will try that today thanks mate.

[Bloodyaussie]

Mate you need to introduce yourself and say G'day... in the intro section, cheers

[ox 123]

Tried new fuel lines still no go,I have been told to check glow plugs incase they are giving a false reading another job bit over it now.

[threedogs]

Need to break the multi meter Ox
Trying to figure out how air can get
into fuel lines via crook glow plugs,

[MudRunnerTD]

replace a couple of sections of fuel line with Clear hose and see which way the the air is flowing.

Do you only have trouble at cold start first thing or throughout the day whenever you turn it off?

I have spent a fair bit of time chasing the same thing and found my problem but unlikely to be yours.

Also disconnect the fuel line from the tank and fit a bottle of fuel and put the line into it and prime and run. Then turn it off and park it up like you would with the line in the bottle. if you have no trouble the next morning then the problem is between the fuel filter and the tank.

Good luck. took me 7 months to find my problem and nearly had me strip the pump off for a full rebuild! which would have sucked for $2000 and then refit it and still have the trouble!!

Start with the clear fuel hose. Buy a couple of brass barbs and jsut fit a 300mm section before and after the fuel filter. dont cut anything, just make the fuel lines longer by that much

[nissannewby]

It might be the primer pump in the filter head which is allowing it to bleed down over night.

[threedogs]

That wasn't the cut fuel line where fuel line runs on top of chassis near body wheel arch, is it ???

[ox 123]

nah mate I have replaced primer bulb that was my first thought as when it happened you could hear the air rushing through and did hear that they can get pin holes in them.

[ox 123]

hey mate seems to be between the filter and tank somewhere oh well another day of scratching my head with this one, must be getting closer theres not much left to look at.

[ox 123]

That came from the diesel specialist from Orange,I cant work out how it could be either.

[MudRunnerTD]

That wasn't the cut fuel line where fuel line runs on top of chassis near body wheel arch, is it ???


That's what happened to mine 3d, bloody thing! Try pressurizing the tank. If you can build pressure in the tank then you will reverse the leak and instead of air in you will have fuel out and it will be obvious. That's how I eventually found my problem.

I had picked up a rock on top of the rear drivers side spring cap where the fuel and brake lines run and it wore a hole through the fuel line and let air in! Half way across the Madigan Line!!!

It presented as a fuel blockage or fuel starvation and the car kept stalling while traveling in 1st low

Was an invisible problem and was impossible to identify.

I ended up cutting the Steal fuel line either side of the spring cap and ripping I out and ran a rubber fuel line over the top. Never had a problem again.

Was a bitch to start and had to prime every morning. If I sat with the engine idling for a while then went to take off it would stall and I'd have to get out and prime it! You should have seen Me trying to do Big Red! Had to like at th bottom before each run!!

Hope this helps you mate. Drive me nuts!

FYI! There in no non return Valve on the back of the pump and if there is an air lam I your line the. It will allow the fuel line to flow backwards while the pump is not sucking causing your trouble

[scotty83]

if you over pump it with the primer does it leak anywhere. I am sure you have tried this. Also may be worth running a fuel pump in the line to see if the constant pressure shows anything. Did you replace the whole primer Pump?

[Cuppa]

Was an invisible problem

A little story that has nothing to do with this thread other than it involves air in the fuel.

Our bus had sat in the shed undriven for around 3 years during the period I was fitting it out. When the time came for it's 'maiden voyage' I took it for a run to a mechanic to be checked over. It ran ok for a while, but then out of he blue lost power, this being accompanied by huge cloud of white smoke out of the exhaust. If I stopped for a short while power would be returned until the next time it occurred. During he drive home these mobile more s reen vents became more frequent. I left t the bus at a farm about 20 Kms from home, confident that it would not make it up the hill from there to our place. Visions of mechanical disaster were top most in my mind.
Following day a friend came over with a heap of cler plastic tubing which we used to extend he fuel line ino the driving cab so we cold see what was going on as we drove. All was initially good, but then the tell tale ign of a hea of air bubbles just prior to a 'power loss/big smoke' event. So the white smoke was unburned diesel with associated power loss, but what was the cause? Existing fuel lines were examined, but no leak found. We did find a non return valve ha been fitted into the fuel feed line, & removed it when we replaced the line. Having done this we took it for another run. Problem still existed, but we found that over the course of 50 or so painful kilometres that although not going away the problem became less frequent & less severe.
My friend hypothesised that the cause may be an exhaust valve sticking open, allowing air in & pushed back into the fuel line on the compression stroke, but with use the valve was 'freeing up'. His advice was to continue using the vehicle & see if the problem went away. Sure enough it did. Subsequently we drove right around Australia without ever a repeat of the problem.

An added bonus was that we found with the removal of the non return valve that we gained an extra 10 kph cruising speed (desperately needed), suggestinging that the valve had been restricting fuel flow.

Cuppa

[Woof]

I have to exactly the same issue with mine, I just put it down to the leak from two injector pipes??????????
Still trying to stop the leaks..

[ox 123]

This sounds exactly like mine, the same thing when i start then stalls then prime then go then stall again. Thanks mate will try that.

[ox 123]

I thought it was injectors on mine as well but after spending about 2 weeks going over and over everything the chase started primer,fuel filter,hoses,clamps it has just gone on and on, so keep in touch and i will keep you posted on whats going on and then hopefully how to fix it. I have been talking to people about it and im supprised how many are having the same issue on all makes and models.

[ox 123]

Just talked to the mechanic 3 glow plugs stuffed replaced them,Starting better but still has air. So now its back to the fuel lines, will see whats next.

[MudRunnerTD]

in behind the read driver wheel is a guard and behind that is the filler hose. There is a Vent there too. using a blow gun on a compressor try and pressurise the tank. the valve there is a simply check valve and you can blow back through it with your mouth if out of the car and not damage it. try a compressor, make sure the car is not wet to start and all areas are dry to view. pressurising the tank (even slightly) will show you the leak in the line.

How i finally found mine..... I fitted a Long range tank to the back before my trip and put that check valve in backwards (really hard to tell which way is which). after many months of searching for answers i pulled it out and reversed it. Problem did not go away damn it. what happened a few weeks later though was we had a Hot day!. on that hot day i drove the GU to the shops. parked it in the sun. Went into the super market and while walking back to the car noticed that the fuel had expanded and was dripping under the car for the first time in 9m months!!! 9 Months it took!

I went home. climbed underneath and immediately knew where it was. Was cut and fixed an a couple of hours and never ever had the trouble again. Happy days. Not much pressure will be needed to show you the leak if it is between the tank and the filter. Put it on the hoist or do it t home.

[ox 123]

will try that, its the best way ive heard to do it so far. I really think thats where it is. Thanks mate...

[ox 123]

if you over pump it with the primer does it leak anywhere. I am sure you have tried this. Also may be worth running a fuel pump in the line to see if the constant pressure shows anything. Did you replace the whole primer Pump? Yeah have replaced it all, the primer wasnt leaking but you can hear and feel the air going through.

[ox 123]

well back again just talked to the diesel specialist the problem is supposed to be the fuel pressure switch on the fuel rail and 1 stuffed injector a quick $2000 gone. He told me that the common rail motor needs the injectors done every 40000 ks but my wagon has 170000 and not a prob my ute only has 80000 ks and there shot. Anyway will see how it goes on tuesday when I get it back.

[BigRAWesty]

Well he's pulling your leg.. pretty sure Nissan recommend every 100 thou..

But its a bummer there shot after 80..
How often does the fuel filter get changed?

Kallen Westbrook
Owner of
Westy's Accessories (http://www.nissanpatrol.com.au/forums/showthread.php?15134-Westy-s-Accessories.-A-small-back-yard-builder.)

[ox 123]

I have put 3 filters on in 3 months. Well got it back from diesel specialist no different probably worse if anything so much for that 2 grand. Really over it now, I dont know where to go from here other than get rid of it, so over it, it has cost me a fortune to try sort this out.

[Lemo79]

Don't give up, you'll miss out on that satisfying moment when you do find it. I have read another thread on here just recently where they used a lift pump down near the tank and hard wired it on till they found the leak. Sorry I'm new to diesels so really only offering words of encouragement, but that sounded like a good idea.

[Lemo79]

This is the thread, http://www.nissanpatrol.com.au/forums/showthread.php?9448-ADVICE-sought-PLS...-YEP!!-ZD30-2003-Nissan-Patrol
Different symptoms but read on.