Fuel issue (need help)

Howdy all,

Just got back from a 4000k+ trip around the Kimberley's towing a Goldstream Storm 1.5T camper. The camping went well and the Wife and kids behaved enough that i can't complain. Anyway, had a slight problem while i was traveling that i heed help to resolve.

While driving on a gravel highly corrugated roads the engine began surging and at one point even went into limp mode. I opened the bonnet and ripped off the chip believing it to be the problem. The car ran faultlessly after removing the chip and a thought i had fixed the problem. Not to be. Two days later the engine began surging again only worse. Into limp mode it went and i thought i was in deep shit. Up goes the bonnet again and after a bit of podding and poking I discovered the manual fuel pump (similar thing you find on a outboard fuel tank) was flat, like it had been sucked dry. I gave it a couple of squeezes and the engine came to life again and off we went.

Everything was fine until we hit corrugations again and the same thing happened. Up goes the bonnet, a couple of squeezes of the the manual pump and all was good.

Now i have an after market 160lt (supposedly) Outback Accessories fuel tank and i've been informed by a mechanic in Halls Creek that the corrugations are causing the fuel to jump around within in the tank causing the fuel pump to suck air. Now this seems plausible but of the four occasions the problem occurred i would have had more that 1/2 a tank of fuel on two of those occasions. The other issue is that this has never happened previously and the tank has done more than 50K km and it never happened when i did the Gibb River Rd last year towing the same camper.

Does anyone have any idea what else may have caused this problem and why it happened on this trip and not on any other?

I wonder if the fuel cap is blocked? Loosen it up and drive around a bit and see what happens.

See if you can get an error code off the ECU. You might have a fuel pressure issue - see if you can get a code for us.

Old.Tony said:

I wonder if the fuel cap is blocked? Loosen it up and drive around a bit and see what happens.

See if you can get an error code off the ECU. You might have a fuel pressure issue - see if you can get a code for us.

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No error codes. My scangauge didn't register one when it went in to limp mode. I doubt it was in limp mode but the mechanic believed it was. The issue is only happening on corrugated roads. The 1800km trip home on the black top was faultless. Had a fuel economy of about 18.5km/100k with a tail wind

I would have fueled up five different occasions between the problem happening. I rang Nissan (dont)care and they simply gave their usual response. Oh, you have picked up some bad fuel. I explained to them this couldn't be the case because the two days and three fill ups between issues. They seemed to agree and then proceeded to actually help me.

The fuel tank i have is meant to have inbuilt baffles to prevent fuel surging. Then again, it is supposed to be a 160lt tank and be buggered if i can fit anymore than 130lts in the bloody thing.

Is the fuel foaming up? It'd have to be dramatic for it to be drawn into the fuel pickup. I thought most diesel fuel had anti-foaming agents added as well, so unless someone forgot to put that in the fuel at the refinery, it surely couldn't be foam.

What about the fuel filter? Has that been changed recently?

Oh, here's something to check - the electrical connections for the MAFS and the fuel rail pressure sensor.

merchant said:

The fuel tank i have is meant to have inbuilt baffles to prevent fuel surging. Then again, it is supposed to be a 160lt tank and be buggered if i can fit anymore than 130lts in the bloody thing.

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Merchant I have the same tank and I experienced plenty of corregations doing the Simo without any issues. I can also verify that 160L was put in the tank when it was first installed. Since then the most I have ever put in is 150L - was just too nervous to drive it any longer with the low fuel light on. Oh and the light comes on with pretty much exactly 25 litres left in the tank.

Old.Tony said:

Is the fuel foaming up? It'd have to be dramatic for it to be drawn into the fuel pickup. I thought most diesel fuel had anti-foaming agents added as well, so unless someone forgot to put that in the fuel at the refinery, it surely couldn't be foam.

What about the fuel filter? Has that been changed recently?

Oh, here's something to check - the electrical connections for the MAFS and the fuel rail pressure sensor.

Click to expand...

I have to put it in to have the rims checked, steering wheel controls changed (peeling) and the climate control linkages fixed. So, i think i'll just get the dealer to check it over after explaining the problem. Hopefully they'll find a problem. Which, knowing the Pilbara, they probably won't.

Where do i find the MAFS and fuel rail pressure sensor?

Bosshog said:

Merchant I have the same tank and I experienced plenty of corregations doing the Simo without any issues. I can also verify that 160L was put in the tank when it was first installed. Since then the most I have ever put in is 150L - was just too nervous to drive it any longer with the low fuel light on. Oh and the light comes on with pretty much exactly 25 litres left in the tank.

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When i first got the tank the installer said i won't be able to get anymore than about 130lt into it due to foaming. Once the metal is impregnated blah blah blah it should be able to get a lot more. Where have the installers put your breathers? That's probably got something to do with it.

The MAFS is just outside your air filter on the tube heading to the turbocharger. It's on the rearward side of the pipe, screwed in from behind, be gentle with it as it's not made of steel and it's about $400 from Nissan. Use an electrical cleaning spray to clean it, IF it's dirty. If it looks clean, don't worry about it. Just clean the contacts of the connector outside.

The fuel rail pressure sensor's harness is on the driver's side of the engine about in line with the oil filler cap in the top, the sensor is connected to the fuel rail.

I am wondering if there's a little bit of air getting into the fuel system, possibly from an overtightened hose on the inlet of the filter or pump, or similar on the pickup line at the fuel tank. As bumps are met, the movement of the fuel hose causes air to be sucked in - it's a long shot, but it's also a cheap thing to check.

Its a blocked filler breather.

Thats the only thing that can cause the primer housing to become sucked in, big vacuum in the fuel tank.

Northside 4x4 said:

Its a blocked filler breather.

Thats the only thing that can cause the primer housing to become sucked in, big vacuum in the fuel tank.

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Is that the thing that sits at the end of the breather pipe near the fuel inlet? Are they cleanable or do i just replace it?