Questions about Fuel Level Sending Unit/Fuel Pump

General engine questions/issues that aren't specific to the other categories
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Questions about Fuel Level Sending Unit/Fuel Pump

By LionHearted1
- Wed Jan 11, 2012 4:00 am #289394 I think I might need to replace the fuel level sending unit in my car, my gas gauge has been pretty off kilter for a while (I posted questions about this earlier) and after some research I believe I've narrowed it down to this being my issue. (Or certainly enough to take a shot in the dark at it.)

Well, while talking about it in my Auto class, some kids told me that there's no way to just replace a fuel level sending unit. You typically have to replace the entire fuel pump.
*Because the unit is inside the pump?*

The only place I could find a sending unit was through Honda, and they wanted $75 for it.

I believe I can get a Walbro 255 for like $125, so for the extra $50, I'd really just rather have an entirely new set up.

Is this true? Do I have to replace the entire pump, or did they just not have any idea what they were talking about?

Also, if I get this new VERY badass pump, is the increased fuel output going to cause any problems for my injectors?

What kind of HP gains could I see out of this?

:?
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By teal_dx
- Wed Jan 11, 2012 2:04 pm #289456 The sending unit is separate from the pump because I replaced my pump once and never touched the float/sending unit.

The pump is under the larger opening, sending unit is under the smaller one next to it.
Image

What mods do you have done to your motor to justify the Walbro 225 pump? If stock, then I think it would be overkill.
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By Apexracing
- Wed Jan 11, 2012 3:56 pm #289467 You wouldnt see any gains with out swapping out your fuel rail and injectors. and getting a tune.
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By LionHearted1
- Thu Jan 12, 2012 4:17 am #289618
What mods do you have done to your motor to justify the Walbro 225 pump? If stock, then I think it would be overkill.


Just the basic bolts ons, I/H/E.
Nothing to really justify it, it was more of... say an excuse?


Thank you for the diagram, I'll pop down to Honda and grab one of those sending units.

By pyang004
- Tue Apr 17, 2012 2:53 pm #302111 my car is giving me wrong fuel level read outs. when i pump a full tank it only reads 3/4 full. when i drive it around it seems to read out okay. say a 45 min freeway drive used almost a 1/4 tank. but some days i go to work and back, about a 3 mile drive, when i come out of work or the next morning it reads about 1/4 less. it reads like im driving a v8.

- its not the gauge or cluster. it had the stock dx one and had the same problem. its since been changed out to an ex for the rpm gauge and still does the same thing.

- im not sure if the filler neck on the tank is the cause of the 3/4 read out from a full pump. might be shutting the pump off early from so reason? but it could just be the fuel sending unit.

- you guys sure the fuel sending unit is separate from the fuel pump. everywhere im looking to buy a fuel sending unit its saying its with the fuel pump. but the pictures dont show a float. can you guys direct me to a good priced site?

- the gas tank has been seafoamed, fuel pump replaced (not by me), and it holds pressure. when i open the cap i can hear it depressurize.
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By teal_dx
- Tue Apr 17, 2012 3:05 pm #302112
fuel pump replaced (not by me)


It's possible that they could have damaged the float. To be sure, I would perform the test in this diagram. I think that's the only way to tall for sure if it is bad.

http://i639.photobucket.com/albums/uu11 ... e_4259.jpg

By pyang004
- Tue Apr 17, 2012 3:30 pm #302117 lol. ^ i just found one of your old post about this.


i dont have a volt meter. it's more that likely the fuel sending unit. i rather spend the money on that right now then on a voltmeter, then end up having to buy a sending unit anyways.

stupid diagram calls it something else "#21 meter unit, fuel" was having a hard time finding it to buy on sites.

looks like $62 + shipping is the cheapest. i dont wanna take to risk of getting a bad one from the junk.

thanks.[/url]

By bks84
- Thu Apr 19, 2012 5:33 am #302282
pyang004 wrote:lol. ^ i just found one of your old post about this.


i dont have a volt meter. it's more that likely the fuel sending unit. i rather spend the money on that right now then on a voltmeter, then end up having to buy a sending unit anyways.

stupid diagram calls it something else "#21 meter unit, fuel" was having a hard time finding it to buy on sites.

looks like $62 + shipping is the cheapest. i dont wanna take to risk of getting a bad one from the junk.

thanks.


so what happens if the fuel level sending unit that's in your car turns out to be in good shape? you're willing to spend $62 on a part, rather than $10-$15 on a tool to help you properly diagnose the issue?

for the record... i do hope its as simple as the sending unit

By pyang004
- Tue Jul 03, 2012 1:05 am #309998
so what happens if the fuel level sending unit that's in your car turns out to be in good shape? you're willing to spend $62 on a part, rather than $10-$15 on a tool to help you properly diagnose the issue?


in a old car like this. yeah. i've replaced several things brand new already. first to know it's been done and done right. and secondly to ensure the car keeps running for a long time. i ended up giving the car to my little sister and rather have it running 100% then waiting for the old stuff to break down on her at god knows where.

and i found out at hond tech that my fuel problem is just how the car was built. nothing wrong with anything. just got to get use to the inaccuracy.

By bigpunn421
- Tue Jul 03, 2012 12:24 pm #310035 the fuel goes through the fuel pressure regulator so it would be hard to get more fuel past that without modding the fpr. unless your pump doesnt flow enough fuel.

if i have 200psi and send it through a 3.5 bar fpr you get 3.5bar. so if the 200psi changed to 100psi and gets sent through a 3.5bar fpr its still 3.5bar.

so you answer to question will better flowing pump require tuning answe no
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