DIY changing fuel pump

**Oyagi** · 03-09-2012, 12:09

Hey guys,

As some of you know, I am having difficulty starting my car up. I changed the main relay and still no startso a buddy came over today with a multi meter and we checked all the fuses. They are all fine, so the problem must be the Walbro fuel pump.

According to the service manual, I need to remove the fuel tank to swap out the pump. Is this the only way? I just want to make sure with guys on the forums to see if there's a simpler trick.

Thanks,
John

**nsx_2k** · 03-09-2012, 12:50

Sadly, I believe that dropping the tank is the only way to get at the pump. There is an access port behind the driver's seat; however, this is for the sending unit and NOT the pump.

One note, you might consider replacing some of the fuel hoses if they are original so that you don't have to mess with them again. Not mandatory, but might be a consideration especially if you plan on keeping the car for a while.

**RYU** · 03-09-2012, 13:50

Having completed this massively PITA task recently.. i'm sad to say there's no other way of doing this w/o completely dropping the tank. I hope your tank is empty. It is not easy benchpressing a tank that's even slightly full

**Oyagi** · 03-09-2012, 14:05

Oh man, this is not cool. I have a full tank (storage mode). I assume I'll need to get under the car too?

Looks like I'll be seeing a tow truck soon... : f

Posted from my iPhone

**swimmingpie** · 03-09-2012, 14:11

I replaced my fuel pump four weeks ago. Actually removing and replacing the pump took maybe 10-15 minutes but removing the tank is quite a task. It is necessary to remove the tank to get to the pump. I had less than a gallon of gas in the tank so it was pretty light, but having a full tank would be a nightmare to work with.

Some things to keep in mind when doing this job:
-The car will be need to be up fairly high to slid the tank out
-The shift cables will have to be removed from the transmission to get them out of the way. Removing the cotter pins holding in the cables is a bit tricky. I used a mirror to see the top of the linkage and was able to pull them out with tiny pliers but not without a lot of work.
-Make sure to unclip the wire going from behind the seats down to the tank.

**mr_goat** · 03-10-2012, 12:23

^ what he said + empty the fuel tank completely + get a friend to help

Installed my walbro myself. About 10 hours total. Easy in theory. Good luck!

BTW, do two easy tests before blaming the pump. Check fuel pressure at the fuel filter (10 min) and if within spec, short the fuel pump resistor (5 min). Its not the pump if fuel pressure is within spec, of course.

**goldNSX** · 03-10-2012, 12:28

We did this task 2 hours ago, the second time. 2 men and three hours if you're experienced working on the NSX.

**mr_goat** · 03-10-2012, 12:36

Originally Posted by goldNSX

We did this task 2 hours ago, the second time. 2 men and three hours if you're experienced working on the NSX.

I did it myself and it was my first time

Others claim 4 hours too, if two people.

**goldNSX** · 03-10-2012, 13:25

It's pretty a tough job if you do it on your one without any helping hands.

**Oyagi** · 03-10-2012, 15:27

I don't have the help plus the space to do this, so it's looking like the shop for me

.

I'm smelling a bit of fuel when I crank the starter but absolutely no sound from the fuel pump. The Walbro is unmistakably loud. All relays and fuses check out too.

Posted from my iPhone

**shawn110975** · 03-10-2012, 17:27

dropping the fuel tank is a PITA

I have done it a few times in my driveway.

I hate doing it and save this fun task for the last possible minute.

good luck try everything else first trust me

**scorp965** · 03-10-2012, 18:14

I'd source a 280lph MKIV Supra Denso pump instead of the Walbro, it's known to last forever, vs Walbro 255's which tend to fail every few years; it also provides better flow. I recently worked on a Supra with 3 of these euro-spec Denso's on a custom drop-in fuel bracket.

Not sure I would take a car to a shop over a fuel pump; get a fluid extractor and some empty cans to drain the tank.

**davidf** · 03-10-2012, 19:04

This is why I payed a tech do do this job. Some jobs I just don't care to tackle. It was $200.00 well spent.

**NSXCessive** · 03-10-2012, 19:54

Originally Posted by Oyagi

I don't have the help plus the space to do this, so it's looking like the shop for me

.

I'm smelling a bit of fuel when I crank the starter but absolutely no sound from the fuel pump. The Walbro is unmistakably loud. All relays and fuses check out too.

Posted from my iPhone

I wish there was another way as well, I too have to drop the tank out of my parts car. PITA you might consider a shop to do it for you if you don't have the help of the room.

**scorp965** · 03-10-2012, 20:04

Originally Posted by davidf

This is why I payed a tech do do this job. Some jobs I just don't care to tackle. It was $200.00 well spent.

I replaced the fuel pump on a Nissan Sentra for a friend a few months after a tech installed a new one; he used tin-snips to cut an access hole in the floor of the car, so he wouldn't have to drop the fuel tank.

Incidentally, the new pump was burned out - not sure if it was another issue with the installation, or if it was just an cheap pump - the new bosch pump has been working fine ever since.

If you do have it done, make sure it's by a person with nsx experience.

**Hugh** · 03-10-2012, 21:01

Originally Posted by scorp965

get a fluid extractor and some empty cans to drain the tank.

The fuel tank has a drain plug on the passenger side.

**goldNSX** · 03-10-2012, 21:17

Originally Posted by scorp965

I replaced the fuel pump on a Nissan Sentra for a friend a few months after a tech installed a new one; he used tin-snips to cut an access hole in the floor of the car, so he wouldn't have to drop the fuel tank.

It's only a Nissan.

**Oyagi** · 03-11-2012, 06:42

So any in tank fuel pump will do the trick?

I bought the Walbro new when I bought the Gruppe M off Stacy, and assumed it will last a long time. I still have the oem but if I go thru all this I might as well get a brand new pump. I'm not keen on going Walbro again.

Denso sounds really good to me. Anyone got a good hookup?

**qqqqball** · 03-11-2012, 11:04

aeromotive has a intank 340lph that is said to last forever, i got one in my Z and it hasn't failed in 60k miles or 7years

**Mac Attack** · 03-11-2012, 13:57

This thread contains two plots showing popular fuel pump capacity at various pressures:
http://www.evoxforums.com/forums/showthread.php?t=42558

If you buy a Walbro255 through other vendors, make sure you get the high pressure version as shown in the chart (not that it really makes much of a difference at our ~50psi). You may want to increase pressure though in the future for those RDX injectors

The SOS Walbro kit contains the HP version.

I have the SOS Walbro kit in hand, but am unsure if I'm going to install it. I may go with the Aeromotive instead. Both have good reputations, it's just that the Aeromotive puts out an extra 60lph at 60psi over the Walbro.

Dave

**L_RAO** · 03-14-2012, 09:09

Originally Posted by scorp965

I'd source a 280lph MKIV Supra Denso pump instead of the Walbro, it's known to last forever, vs Walbro 255's which tend to fail every few years; it also provides better flow. I recently worked on a Supra with 3 of these euro-spec Denso's on a custom drop-in fuel bracket.

That's a great tip - I'll defer to OEM Japanese whenever possible.

BTW, what is the OEM NSX fuel pump rated at, flow-wise?

**scorp965** · 03-14-2012, 18:19

Originally Posted by L_RAO

BTW, what is the OEM NSX fuel pump rated at, flow-wise?

According to SOS, around 155lph

**L_RAO** · 03-21-2012, 14:27

So, according to RockAuto.com there are 2 choices for the Supra turbo Denso fuel pumps:

1. OE replacement fuel pump and strainer kit ($196.79)

http://www.rockauto.com/catalog/moreinfo.php?pk=2142696

2. OE replacement fuel pump ($231.79)

http://www.rockauto.com/catalog/moreinfo.php?pk=2143036

Which doesn't make sense to me; why would you charge MORE while offering LESS?

**nsxotic911** · 03-21-2012, 14:33

Is this thread implying that we have a Walbro-alternative for fuel pumps that will work with a Comptech supercharger? I have not liked the Walboro and would love to replace it!

**RYU** · 03-21-2012, 14:35

Originally Posted by L_RAO

So, according to RockAuto.com there are 2 choices for the Supra turbo Denso fuel pumps:

1. OE replacement fuel pump and strainer kit ($196.79)

http://www.rockauto.com/catalog/moreinfo.php?pk=2142696

2. OE replacement fuel pump ($231.79)

http://www.rockauto.com/catalog/moreinfo.php?pk=2143036

Which doesn't make sense to me; why would you charge MORE while offering LESS?

This is the Denso pump
Denso 195130-1020 Supra Turbo fuel pump

Knowing what I know now, after going thru the PITA fuel pump install, I wish I had gone with the Denso instead of the Walbro. You might want to start looking at upgrading some of the oem wiring. Not sure what's there now is designed to support that much amperage.