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Smithers 07-01-2008 06:46 PM

2000 Nissan Xterra Fuel Problem FIX
So my sister has owned a 2000 Nissan Xterra since it was brand new. For the first time ever it has absolutely stopped working. BOOM just like that, crapped out. Since I have been around automotive shops long enough I could pretty much figure that the fuel pump wasn't working. So since we were in a hurry to get this back on the road I got a fuel pump overnight and installed it.

It worked for about 25 ft! So now I could easily see that I have an intermittent electrical problem that effects the fuel pump. So what's left? The sending unit! What is a sending unit? Well it sound complicated, mysterious, sounds like a relay or something right? Well it's the plastic cap that fits to the top of the fuel tank and also encases the connectors for the fuel leads (plugs) and also includes the fuel level sensor/sender. They call the thing that floats on the fuel and monitors the level: a sender. So I guess they call the whole fuel tank cap a sending unit. Sounds good. OK I just had to get that out of the way for people that might not know exactly what it is. They surely don't give you a good explanation anywhere!

Here is a look at this commonly defective part!

Of course this unit is brand new in the box. I'll be going over the process of removing it and replacing it if you have the patience to scroll down.

Smithers 07-01-2008 07:03 PM

If you need to replace the fuel sending unit you are in luck! This is a very expensive operation at an auto shop but it's really simple. You don't even need to take the tank out from under the truck. First you might want to make sure that this is really your problem. You want to get a good close look at your sending unit to see if there are any signs of deterioration. Read on, I'll show you what to look for. But before you get started taking things apart:


The top of the fuel tank can be accessed from under the rear seat on the passenger side of the Xterra. To get to the sending unit you simply remove the rear seat and pull up the carpet access pad to expose the cover plate. Up until this point all you need is a 10mm socket or wrench.

Here is the cover removed and you can see the fuel connections and the electrical wires. One plug is for the fuel pump itself and the other plug is the for fuel level sensor. The fuel lines are simply fuel in and fuel out. I highly recommend you clean things up to make the connectors easier to see and remove.

Believe it or not, the fuel lines are easy to remove. You squeeze the sides of the lime green plastic retaining clips and pull at the black fuel line connectors to remove them. The electrical connectors are normal connectors that can be removed easier if you have a very small screwdriver to bend the tabs up while you wiggle them free.

Since it's the first year model Xterra its a little dirty at this point. Do yourself a favor and clean things up a little and MAKE SURE you remove and wipe away any dirt or rocks that can fall into the tank once the unit is lifted upwards.

Smithers 07-01-2008 07:14 PM

Clean things up, carefully remove the connectors and presto... you are ready to remove the sending unit out from the tank.

While you are working on the fuel tank now would be a good time to clean up that nasty old rusty ring that holds down the fuel sending unit. Just wire brush it off at least and then spray paint it with anything you have handy. Anything is better than rust and it will last a lot longer when it's coated with paint.

Here is the ring that I painted nice and clean. Big difference huh!?

Smithers 07-01-2008 07:28 PM

So what are we looking for to show us evidence of a bad connector? Why isn't a good electric signal getting to the fuel pump to keep the truck running? Here is a way you can look at the connectors really closely without completely removing the sending unit.

This is a mirror showing us the good fuel level sensor connector. The leads (solid blade of alloy that carries electrical current) are nice and clean. Now look below. Excuse the old mirror that is wearing down and not optically perfect, BUT if you look close you can see some green oxidation / crud. This is part of the lead that is now exposed by the plastic that has worn away because they didn't design the part correctly. The heat from the fuel pump wire eventually wears down the plastic and it breaks down and flakes off which exposes the electrical lead.

The connector should be perfectly white and clean on the inside where you see the green oxidation. The connectors are sealed with rubber built into the connector so there is no way dirt will get in there. But if the plastic wears away the air is enough to cause corrosion and it will break down over time.

Ok now you can pull it out and replace it. I think the whole fuel sending unit was just at $130 us dollars. The fuel pump on the other hand is more like $300. I replaced this one just because I don't want the possibility of the pump burning out and having to open it back up!! I swapped it out and I'm done with this forever.

If anyone wants to buy a used fuel pump let me know. I'll make you a killer deal on the one that I removed. It works just fine. I just replaced it as a preventative measure on a truck that needs to run every single day as a commuter. =]

Smithers 07-01-2008 07:32 PM

Here is a shot of the connectors. These are high quality connectors that will last for years and years. They are reinforced and have a rubber seal to keep out dirt and moisture. Be careful taking them off as you simply use the tab to remove them. You don't want to damage these! They are pretty strong but too much force or yanking will absolutely ruin your day and add hours to your repair.

Smithers 07-01-2008 07:43 PM

So here is what you see when you actually remove the fuel sending unit and inspect it. Unless you have a really clean mirror and plenty of light you wouldn't be able to see this without removing it. But here is the whole cause of the Nissan Xterra fuel system problem. This is why your Xterra will one day just crap out and die on you in traffic somewhere on the road when you least expect it. The truck will be running just fine and then the engine will basically just stop running as you pull over on the side of the road clueless. I've seen lots of different brands of fuel pumps die and fail in other lesser quality vehicles but this is just a small flaw that will do the same thing... leave you stranded on the side of the road wondering how much THIS is going to cost you.

I'm not very happy with my dealerships response to the problem. Their response was basically, "no no there isn't any recalls on your truck I put the VIN into the computer system and nothing came up." Yeah NOTHING at ALL? NO RECALL OR SERVICE BULLETIN AT ALL?? That's odd because if you boot up an ALLDATA computer it will show you all sorts of issues that require updated parts and recalls.. interesting.

I've been meaning to call Nissan North America up and have a talk with them. I've heard of another person who called corporate and they promptly reimbursed the monies that he had to spend to have the problem fixed. I'll update things when I have a chance to call them myself

Smithers 07-01-2008 07:53 PM

Now to get dirty! You can now pull up the unit a couple of inches and expose the fuel connectors and the one electrical connector.

Yeap you won't have much room to work but just really squeeze the tabs on the fuel lines and pull them away. They will come off quite easily IF you squeeze the tabs enough. The electrical connector also needs a good squeeze and it isn't hard either. You just need to use your head and locate the tabs and get a good grip on them. Here is a closer look for reference.

Smithers 07-01-2008 07:56 PM

If you dare to look down into the fuel tank this is what you will see. But basically all you need to do is replace your fuel sending unit with the new one, push on the fuel lines and connectors and your all done.

Smithers 07-01-2008 08:12 PM

Now if you want to get brave and replace the fuel pump I'll run you through that in this one post. There is almost no way you can do it with gloves on since it's so damn slippery in there with the fuel. I think the Xterra had about 1/3 of a tank in it when I did the work on it so just make sure you take more fuel out if you want to make it easier on yourself. I'm still alive so having my hand in fuel for 5 minutes didn't kill me. I don't recommend more than that though! Make sure to degrease your hand and put some vitamin oil on it as fast as you can when you are done dunking your hand in there.

SO study these pictures as they will save you some time. There are four little tabs that connect the lower and upper cover that encases the fuel pump. You can use your fingers or a screwdriver to push the tabs in to release the upper cover. They are really flexible and easy to release. When you get the two from one side done the cover will open up and the pump can be pulled loose fairly quickly.

Just like you would see when you first remove the fuel sending unit:

And with the top portion of the fuel pump casing removed:

A shot of the upper enlosure removed and so you know what your working with. Having one arm in the hole you won't be able to see what you are doing. You have to work completely from feeling around, hence the reason you can't really use gloves. It's faster without them.

Here is a look at the bottom of the fuel pump enclosure. So basically it's held in the plastic housing and insulated with the foam strips. Simple enough.

Here is what the little sucker looks like out of the tank. The pump is just a small unit with a wire and hose sticking out of it. The reason it's so expensive is that is has to be super high quality as it's made by Bosche. It's a good unit and they rarely go out. Now the Jeep Grand Cherokees and Chevy trucks/suvs use them up every 5 years like clockwork! Be glad you have a high quality fuel pump.

Put in the new fuel pump just the way you removed it. Easy as that! Now go wash your hands before dinner.

Smithers 07-01-2008 08:24 PM

And here is what you got all dirty for. A nice new fuel sending unit finally installed!

Now that's whats we like to see. And as an added bonus I'll throw in a few pictures explaining where the fuel filter is and how to replace it. See how easy this stuff is? You hardly need any tools and you can save yourself a fortune doing it yourself out in the parking lot. :lol:

Smithers 07-01-2008 08:32 PM


Ahhh now for peace of mind you better replace the fuel filter. You KNOW you haven't ever done this and it needs to be done every few years. If you have over 80K miles on your truck you better do it! They are cheap so don't worry.

Now it took me a minute to find the fuel filter. That's because the little sucker is hiding behind a heat shield type protector.

And exposed you can see the fuel filter is just held in place by one nut and a couple of hose clamps. Swap in the new one and your done in 15 minutes.

Good work. You just saved yourself a bunch of cash.

Smithers 01-09-2009 09:32 PM

Hey quick update. If you Google this problem you won't see just me as the only person who has had this problem with their Xterra, oh no. Just to show us EXACTLY what goes on in there when this particular sending unit goes bad a fellow Xterra mechanic has sent me his pictures. Check out these close-ups.

Smithers 01-09-2009 09:33 PM

And one last picture. I hope we don't have to keep changing out this fuel sending unit every 6-7 years. At least we'll be really good at it and fast when we have to do it a 2nd time. :P

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