NEED HELP!! Code 77

Hey guys,
I am starting to lose my mind and am hoping somebody may have some advice that can help.

I recently bought an '03 ZD30 GU, all factory, no mods at all.

a few days after I bought it, it started throwing engine lights with code 77, I had a reconditioned fuel pump put in under warranty. when I picked the car up, it started throwing engine lights with code 77......... back to the mechanic, another reconditioned fuel pump.

got the phone call that is was all ready to go, picked it up.... halfway home, code 77. I turned back around and took it straight back to the mechanic, his solution you ask??? another fuel pump!!!!!

so far, this patrol has had 3 reconditioned fuel pumps, numerous new filters (currently has a Nissan one installed), has had a new water sensor fitted for the bottom of the filter, fuel lines have been pressure tested to check for air leak, I have pulled out and checked the fuel pickup in the tank, the fuel tanks are both spotless and the fuel is crystal clear...................... still throws code 77.

It does seem to throw codes when the main tank gets between 3/4 and 1/2 or lower, don't seem to have much drama when the tank is full.

does anybody have any experience with this? is there something I am missing? I am about ready to either flick a lit match into the bloody thing....... or worse yet, trade it in for a Toyota!!!

any help would be appreciated..

cheers,

Quote:

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Originally Posted by colac pants man

It does seem to throw codes when the main tank gets between 3/4 and 1/2 or lower, don't seem to have much drama when the tank is full.
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I reckon your clue is there. Code 77 doesn't necessarily 100% mean it's a stuffed up fuel pump. It can be anything along those lines.

Here are few other threads for you to go through.

http://www.nissanpatrol.com.au/forum...ent-Power-Loss

http://www.patrol4x4.com/forum/3-lit...e-77-a-180010/

http://www.justanswer.co.uk/nissan/7...rol-fault.html

Some good info there dom. Nice work.

Update: drove down to cairns this morning, emptied the sub tank and almost full main tank, threw about 6 engine lights at me during the drive.

filled up before heading back up the range to Mareeba and didn't get a single engine light with both tanks full. I gave it a bit coming up the range to see if it would starve but went like a charm.

could there be something causing a vacuum in the tank setup that causes the FP to starve and throw fault codes?

I got the bits and pieces to do the spill line mod this morning, but not sure if this will even help...... cant hurt I guess

Quote:

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Originally Posted by colac pants man

Update: drove down to cairns this morning, emptied the sub tank and almost full main tank, threw about 6 engine lights at me during the drive.

filled up before heading back up the range to Mareeba and didn't get a single engine light with both tanks full. I gave it a bit coming up the range to see if it would starve but went like a charm.

could there be something causing a vacuum in the tank setup that causes the FP to starve and throw fault codes?

I got the bits and pieces to do the spill line mod this morning, but not sure if this will even help...... cant hurt I guess

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Yep. If you keep eliminating causes related to code 77, I reckon you'll get there eventually. It's a better approach IMO than throwing parts at it, particularly in modern diesel engines where the cost of spare parts can cost you your house. ;)

Is it a leak in the fuel line where it sits on the chassis near the wheel arch?

Fuel lines were pressure tested at the local diesel place, Will check again though

Quote:

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Originally Posted by colac pants man

Fuel lines were pressure tested at the local diesel place, Will check again though

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Pressure testing should ideally rule out any fuel leaks.

did the spill line mod, no joy, still throwing lights when the fuel gets down.

I work DIDO so car will have to wait for 9 days til I get back, then its getting a lift pump.

Quote:

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Originally Posted by colac pants man

did the spill line mod, no joy, still throwing lights when the fuel gets down.

I work DIDO so car will have to wait for 9 days til I get back, then its getting a lift pump.

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I've been wondering whether it has something to do with fuel level sensor(s).

Did it run badly when the engine light first came on? Or anytime it came on?

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Originally Posted by growler2058

Did it run badly when the engine light first came on? Or anytime it came on?

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It feels like it goes flat and then loses acceleration, it's still drivable and sounds fine but you just font have any power. It hasn't ever just shut off

Quote:

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Originally Posted by colac pants man

It feels like it goes flat and then loses acceleration, it's still drivable and sounds fine but you just font have any power. It hasn't ever just shut off

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Is that what we call "limp mode"? Can a fuel starvation/fuel blockage at the fuel pickup point in the tank/plumbing cause that?
Worth finding out that, I guess.

Drove an hour and a half this morning with no dramas. Tank got to 3/4 and started throwing codes. Topped up with the sub tank so main tank is full, sub tank is half and still throwing codes like crazy

Quote:

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Originally Posted by colac pants man

Drove an hour and a half this morning with no dramas. Tank got to 3/4 and started throwing codes. Topped up with the sub tank so main tank is full, sub tank is half and still throwing codes like crazy

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Fuel level sensors/indicators aren't connected to any fault codes, are they?
I'm thinking there is a pickup/plumbing issue, assuming the pump(s) are good(since you've got them replaced few times).

Quote:

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Originally Posted by dom14

Fuel level sensors/indicators aren't connected to any fault codes, are they?
I'm thinking there is a pickup/plumbing issue, assuming the pump(s) are good(since you've got them replaced few times).

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Thats what I'm thinking. @nissannewby does this sound plausible?

Could be. The fact it is changing after the tank has been opened and filled does kind of point at a vacuum. Once a vavuum is present the pump cannot pull fuel. Check the tank breathers and associated lines for blockages or kinks.

Were all the fuel lines tested or just the ones in the enginebay?

Quote:

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Originally Posted by nissannewby

Could be. The fact it is changing after the tank has been opened and filled does kind of point at a vacuum. Once a vavuum is present the pump cannot pull fuel. Check the tank breathers and associated lines for blockages or kinks.

Were all the fuel lines tested or just the ones in the enginebay?

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I think they were tested from the tank forward. Breathers definitely not checked. Will get it all checked when the lift pump goes in next week. Hopefully that will be the end of it

so apparently my observations about fuel level are incorrect. I drove the piece of s*&t down to cairns yesterday with 3/4 of the main tank and an empty sub..... didn't throw an error until after about 1 hour of driving. same thing today, drove around on half a tank with no dramas, only started throwing codes after about 40 mins. I filled both tanks and it kept on throwing codes and going into limp mode. I am now assuming that it has something to do with the engine bay heating up. I am gonna double check that the small rubber seal is in place on the fuel filter, I checked with the bloke who did the fuel pumps and it also has a new primer assembly so this cant be the problem either......... I don't think there is anything relating to the fuel system now that hasn't been looked at or replaced so I'm wondering if this lift pump is gonna be a waste of time/money. anyone have any other ideas about what this could be............ keeping in mind that I am really starting to hate this car and don't wanna spend too much more money on it, I'm at the point where I would rather set it on fire than put any more effort into it.

Bugger mate sounds like a nightmare. Have you tried taking the cap off and going for a drive to rule out any breather issues? Good luck with it sure it will be worth it when finally sorted. . .

Sent from my GT-I9506 using Tapatalk

Yeah done the drive with the caps off, still threw codes. Have been noticing it tends to play up when the auto transmission goes up a gear.

the breathewr,sometimnes wasps get in there and make the nest..this prevents air getting into tank so lose pressure

sorry never read this bit..went on info on other page...

Thanks for everyones help and advice, in the end i was able to fix the problem......... I got rid if the patrol. Swapped it for a rav4 for the mrs and i'm getting a lancruiser.