Is L300 fuel sender unit repair possible?

ontheebrink · Post by **ontheebrink** » Fri Apr 06, 2018 10:47 am

My fuel gauge is only reading at 3/4 full with a full tank and drops quickly from there. Is it difficult to repair the fuel sender unit? I'm having a hard time finding a replacement that isn't used. Since I already own one of those I might as well try and fix it.

I don't have it out of the vehicle so I can't tell you exactly what the issue may be but I assume it's got some buildup that can be cleaned off. Occasionally it will read a full tank then drop down to 3/4.

If anybody has done this I would like to hear about issues or things to look for.

thanks

north54 · Post by **north54** » Fri Apr 06, 2018 2:46 pm

I have kinda the same issue and have lived with it for 5 years. My gauge does go to full but once it gets around 1/2 it drops to E. I keep an eye on the trip meter and zero it out every time I fill up. I roughly know how many km's I can go before I need fueling. Having a working fuel light on the dash helps too. Another reason I carry extra fuel tanks on my roof!

Pulling the sender out of the tank is an option for a fix but that seems like an arduous job.

Good luck.

ontheebrink · Post by **ontheebrink** » Fri Apr 06, 2018 3:24 pm

I don't know about arduous. I can see it on the tank in front of the back left tire while standing next to the car. It'll probably take 2 minutes to remove it while only getting my fingers dirty. However, a three hour job is worth daily peace of mind in my opinion.

I don't want to yank it out and mess it up with out having a bit of feedback about what I may be getting into. It looks like people do this on other cars and I'm hoping somebody did the same with an L300.

Post by **Growlerbearnz** » Fri Apr 06, 2018 4:37 pm

If it's a 4WD automatic you should have two senders, one in each tank. Manuals and 2WDs have one tank.

I've not tried removing the senders with the tank in place, but it might be possible, or you might have to lower the tank slightly. Be gentle with the three little nuts. If they're seized you can shear the stud, and then you've got a much more irritating job on your hands.

The sender itself is just a coil of resistive wire, with a wiper arm that makes contact. It's hidden inside a metal casing, and you need to gently un-bend the tabs that hold it together.

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I suspect the fault is wear in the bushes that hold the float arm. This allows the float arm to move sideways, causing the wiper arm to lose contact with the resistive coil. I suspect you've got intermittent contact, since your fuel gauge only drops a little.

Before you modify anything, move the float arm up and down and listen to the sound of the wiper arm on the coil. It should make an even "zzzz" noise. If the noise goes quiet, that's where the contact is getting lighter. Bend the wiper arm a little to increase contact pressure, and listen again. It might take a few tries before you achieve reliable consistent contact. Once you think it's fixed and before reinstalling the sender(s), I would dry test the sender by plugging it in, turning on the ignition, and checking that the fuel gauge works properly.

While you have the sender out, also check that the float still floats.

ontheebrink · Post by **ontheebrink** » Fri Apr 06, 2018 5:23 pm

Thanks, Growlerbearnz!

I have 4wd automatic diesel. The manual is only showing one tank and the sender on the outside of the tank near the rear wheel. I'll look around tomorrow to see if there is another, raining like crazy here. Thanks for the advice, seems simple enough.

I noticed that the sender is almost identical to the Pajero sender (MB571603) just with different angles for the float arm and sensor arm. You can buy them new for $15. Has anybody tried modifying one as a new part? For the price it seems that it may be a better way to go instead of taking it apart.

Post by **Growlerbearnz** » Sat Apr 07, 2018 3:03 pm

The workshop manual has a number of omissions when it comes to Japanese domestic models. There's nothing about the Karaoke machine either, which is unforgivable.

The front sender is on the driveshaft/gearbox side of the front tank. Check out the TRL writeup on dual tanks and how they work: http://www.delica.ca/forum/viewtopic.php?f=91&t=17225

The Pajero and Delica single-tank senders are physically (mostly) identical, but not electrically. Your two senders are each half the resistance, so that when they're connected in series they add up to the same resistance as a single-tank sender.

ontheebrink · Post by **ontheebrink** » Sun Apr 08, 2018 12:36 pm

@GBNZ

Got it, my karaoke machine works so I didn't even bother looking it up in the manual. The sound actuated lighting system is a different story.

I can easily remove the sender from the rear tank. Do you think I'll have to drop the front tank to remove that one?

Thank you for the link, by the way, very informative.

Post by **Growlerbearnz** » Sun Apr 08, 2018 1:41 pm

ontheebrink wrote:Do you think I'll have to drop the front tank to remove that one?

Not sure, but it doesn't look any more difficult than the rear one. You can certainly get at all the nuts easily enough. The tricky bit might be manoeuvring the float arm out, but I guess you'll find out!

And your karaoke machine works? Neat! (Or did you think I was joking about the (optional, Super Exceed trim level only) karaoke machine?)

ontheebrink · Post by **ontheebrink** » Sat Apr 21, 2018 5:22 pm

Quick update in case anybody is wondering. I got them both out pretty easily and replaced them with new ones I got on Amayama. It took about 30 minutes and now I have a half tank of gas where it said empty.

No need to move the tanks. The rear one is accessible through the back left wheel well and the front one is on the inside underneath with very little in the way.

Unfortunately I also went to replace the glow plugs and two of the tips broke off the old ones while removing. One is still stuck in the hole and the other fell inside the motor. I'm leaving this one up to a mechanic with better tools, knowledge, and patience.

Post by **Growlerbearnz** » Sun Apr 22, 2018 4:07 am

Thanks for the update, it's good to know the senders come out easily. I'm glad the fuel gauge is working again, but bad luck with the glow plugs!

Hopefully the broken bits are still in the precombustion chambers. If you remove the injectors you can probably get tweezers in there, or maybe apply a vacuum cleaner to the injector hole and turn the engine by hand until one of the valves opens and the bits of plug get sucked out. You'd need to examine any retrieved pieces of glow plug and match them to the rest of the broken plug, to make sure you've got everything.

Probably safest to remove the head though, you really don't want a chunk of ceramic glow plug going through the engine.

bigsleep55 · Post by **bigsleep55** » Tue Jan 15, 2019 7:15 pm

ontheebrink wrote: ↑Sat Apr 21, 2018 5:22 pm Quick update in case anybody is wondering. I got them both out pretty easily and replaced them with new ones I got on Amayama. It took about 30 minutes and now I have a half tank of gas where it said empty.

No need to move the tanks. The rear one is accessible through the back left wheel well and the front one is on the inside underneath with very little in the way.

Unfortunately I also went to replace the glow plugs and two of the tips broke off the old ones while removing. One is still stuck in the hole and the other fell inside the motor. I'm leaving this one up to a mechanic with better tools, knowledge, and patience.

Hi! My fuel gauge was working and now doesn’t register at all!

I see you solved this issue by replacing the sender with new ones, can you please share the part number/s you ordered?

Did you have to modify them at all? Or was it as simple as replacing the old with the new?

sk66 · Post by **sk66** » Wed Jan 16, 2019 9:33 am

bigsleep55 wrote: ↑Tue Jan 15, 2019 7:15 pm I see you solved this issue by replacing the sender with new ones, can you please share the part number/s you ordered?

https://mitsubishi.epc-data.com/delica_ ... 477,16486/