Fuel Pump INSTALL (basic but educational)

Fuel Pump INSTALL (basic but educational)

This weeks blog post is a little lack luster, just due to so many other big things happening right now. Track prepping for Saturdays event, Finishing up Pats K swap, completing Ever’s NSX top end gasket overhaul (before the track event on Saturday), working 40 hours a week, and trying to sleep somewhere in between.

The last track day I did in my K20 EG, my Walbro fuel pump died. After more than 10 years of amazing service it finally went kaput, dying halfway through the event. Luckily Patrick had an extra OEM GSR pump that I threw in just so I was able to enjoy the latter half of the event, and actually go on to PB. Of course an OEM GSR fuel pump isn’t the most ideal pump for a tuned K20 with 250 hp. I just didn’t want that dead pump to put an end to my day. After that event, I drove my car home and parked it away in the garage, never touching it for a few months while focusing my attention on tracking my 4 door. As I ordered more and more parts for my 4 door, in the back of my mind I knew that I really needed to get a new Walbro fuel pump for my EG. An OEM GSR pump is anywhere from 80 LPH-131 LPH (liters per hour) depending on what year GSR. This was definitely not going to provide adequate fuel for my thirsty K20. An OEM B series injector size is 240cc, while the OEM K20 is 310cc. The Walbro pump I was previously running was the 255 LPH one which is 2-3 times more LPH compared to the OEM GSR pump I was running. The Walbro pump was definitely more suited for the larger injector on the K20 and the more demanding tune it has on it. Finally one day I decided to pull the trigger and order a replacement pump. As you can see from the facts, there was defiantly a risk of leaning out my engine, and possibly doing damage, so I really needed to get a replacement in before I drove the car anymore.

See even though this post seems a bit remedial, there are some good educational facts that I bet you didn’t know before.

This should be a no brainer, but I wanted to mention it anyway. ANYTIME you are swapping ANY motor in your car… Honda, Nissan, Toyota, etc… you should ALWAYS put an after market higher LPH fuel pump in to help ensure proper fueling. Yes most people will get a FPR (fuel pressure regulator) and gauge to complete the upgrade, but at the VERY least get your self a new higher flowing pump. A higher flowing pump will help keep the fuel flow consistent.

On to installing the new pump in my car, which was just another Walbro 255 lph pump… Since my Eg is all stripped its very easy to access the fuel pump, BUT if you have full interior don’t worry ill try to guide you through the process of getting to it. All you really need to do is just remove the “bench” part of the rear seats. This is done by removing the (1) singular bolt that holds it in place, and it can be found by squeezing a socket in-between the back of the rear seat and the bench part in the middle by where the seat belts come thru. Once the (1) bolt is removed you can lift the “bench” part up, making it somewhat vertical then you will be able to slide out the metal tabs that “lock” the front part of the “bench” to the chassis. I make it sound more complicated than it is, but trust me its very easy. What you will now see is pictured below. The silver cover is the access panel to the fuel pump. The cover is slightly different between chassis but its all the same method.  Before you do ANY of this, please disconnect the battery and its probably best if you don’t have a topped off tank. Remember that you are dealing with highly flammable stuff here.

_dsc4513_48741663526_o

Remove the X4 Phillips screws that hold the cover on.

_dsc4519_48741663631_o_dsc4520_48741336213_o_dsc4521_48741662841_o_dsc4518_48741847782_o

_dsc4522_48741662711_o

There should be enough slack in the wires so that you can just slide the cover out of the way as seen below.

_dsc4524_48741335803_o_dsc4526_48741847117_o

There is a clamp on the return line. this is easiest removed with a 45* or 90* needle nose plier.

_dsc4527_48741335498_o_dsc4530_48741661901_o

If the line is reluctant to come off, try pushing it on more. This will sometimes help break the seal and allow the line to come off easier. DO NOT go crazy with pliers and mess up the line, this can cause leaks and be a real headache.

_dsc4531_48741661826_o

This is the fuel pump power. just simply unclip and move out of the way.

_dsc4528_48741662126_o

Like so.

_dsc4529_48741846842_o

Lastly the 17mm banjo bolt that is the fuel pump outlet (supply line)

_dsc4533_48741661626_o

Make sure when removing the banjo bolt that you pay attention the X2 crush washers and don’t lose them. You can reuse them, I’m sure people say this is a bad idea but I have done it multiple times in my life and have had no issue. If this makes you feel uneasy,  you can always just throw X2 new ones on to be safe.

_dsc4534_48741846427_o

Now remove the X6 10mm nuts that hold the fuel pump assembly to the fuel tank.

_dsc4535_48741334638_o_dsc4536_48741846272_o

Once they are are removed the whole assembly will easily slide out of the tank. Be gentle when you take it out as it might take some contorting to get it all out. Don’t just force it out, it may take some time but it will come out. _dsc4537_48741846182_o

This is what the whole “unit” will look like once removed. (again different chassis may vary slightly but it will all be done the same way.

_dsc4538_48741661156_o

To remove the fuel pump, begin by unscrewing the Phillips screw that has the ground attached to it. This screw is a one time use locking thread screw, I usually am able to reuse it though. If when you go to tighten it back down and it doesn’t get tight you will need to use a new or different screw.

_dsc4542_48741845612_o

Once the ground is removed you can now pull the pump from the bottom of the hanger assembly. There is a rubber grommet that holds it tightly in place, just use some force to free it. (you’ll see what I mean when you get to this step.)

To free the pump filter there is small circular clip that holds it on a plastic tab. It can be challenging to get it off just because the rubber grommet is on the pump and leaves little room to access the clip. I usually use small picks, and don’t really care if I damage the old pump (since I’m replacing it anyways) The new pump should come with a new filter, and clip anyway. The only thing you are concerned about is the rubber grommet because you will be reusing this.

_dsc4543_48741660516_o

Next loosen the clamp holding the hose to the pump. This can also be a pain to remove, and most fuel pumps should come with a new hose. Usually I just take a razor and slice the hose to easily remove it. (this hose came off easy so I didn’t need to use a razor)

_dsc4545_48741333613_o

Now there is a “safety” clip that needs to be removed before you are able to actually unclip the fuel pump power wire.

_dsc4546_48741333503_o

Use a pick, or something with a really small point that can depress each side.

_dsc4547_48741659936_o

This is what the “safety” clip looks like once removed. Now you are able to use you finger to unclip the power wire from the pump.

_dsc4548_48741844772_o

This is what it looks like all taken apart.

_dsc4550_48741844447_o

Here is everything that comes in the new kit.

_dsc4551_48741332723_o

Old GSR pump on the left and new Walbro pump on the right.

_dsc4552_48741659131_o

Everything that I will be using from the kit.  Notice the new small silver clip that holds the filter on the pump. (its sitting on the filter)

_dsc4554_48741658776_o

As you can see there is a difference in the actual lengths of the pump. this isn’t a big deal.

_dsc4556_48741843497_o

Just line up the pump and ensue that the over all length, from the bottom of the pump to the top of the rubber hose is the same length, as seen below. (I made the new hose slightly shorter because the old one was a bad bit too long)

_dsc4557_48741843337_o

You must put the rubber grommet on before you attach the filter. in the picture below you can sort of see how I have the silver clip on the nipple coming off the pump. You will need to use a pick or small pointed equivalent to press the clip on. (this is sort of challenging and its best to use a second set of hand to help)

_dsc4559_48741658086_o_dsc4560_48741658036_o_dsc4563_48741842912_o

It’s important that you have the correct length hose. Too long and you won’t get the pump to go on the hanger. Too short and the pump won’t have enough pressure to secure it to the hanger. You can also finely tune this by adjusting how far the hose goes on the metal tube attached to the hanger assembly.

_dsc4564_48741331263_o

It’s also important to notice that the grommet only really fits one way. It’s pretty obvious as it fits the contours of the hanger. The filter also only goes on one way and there really isn’t a way to do it backwards.

_dsc4568_48741842532_o

Now reinstall everything you just removed. Once you have the new hose on and tightened with the pump perfectly wedged in the hanger. You can now reinstall the power wire clip. (make sure you hear it “clip” in.)

_dsc4569_48741842427_o

Now reinstall the “safety” clip

_dsc4570_48741330703_o

Re install the ground wire.

_dsc4572_48741656956_o

And don’t forget the keep the install clean by reattaching the plastic black clip on to the hanger.

_dsc4573_48741330308_o

With everything all securely reinstalled you are now ready to put the whole assembly back in the tank. Just like when you removed this you will want to be careful and not force it back in. There will be more contorting to reinstall it, you will feel when its actually in properly because it will just sort of fall into place, as if it members how it was before. You can mess up a lot if you get frustrated and just jam it back it, just take your time and ease it in. (lots of twisting, and different angles will help get it back in)

_dsc4575_48741841722_o

Once its sitting in completely flat on the tank you can reinstall the X6 10mm nuts, and tighten in a star pattern evenly. Be careful to not pinch or damage the gasket because that can lead to leaks in your fuel system.

_dsc4576_48741841617_o

Notice that it looks like there is a “stuck” on crush washer. Actually though, it’s just a part of the mating area. So DO NOT try to pry it off! (see below)

_dsc4577_48741656431_o

Now take one crush washer and put it down.

_dsc4578_48741656301_o

Put the banjo fitting on top of the crush washer and slide the other crush washer on to the banjo bolt like below. Now you can thread the bolt in and tighten (you don’t want it to leak, BUT don’t go crazy)

_dsc4579_48741329648_o

Reinstall the return line.

_dsc4580_48741329563_o

Reconnect the power wire.

_dsc4581_48741655961_o

place the rubber cover on properly to keep the install very neat and tidy.  Before putting the cover back on you can reconnect the battery and prime the fuel system to see if you have correctly reinstalled everything. The new Walbro fuel pump will be substantially louder than the OEM pump, this is normal.

_dsc4582_48741329393_o

Lastly put the cover back on and screw back in the X4 Phillips screws. These don’t have to be too tight, and they are actually threaded into plastic plugs that can strip easily.

_dsc4583_48741329328_o

Well there you have it, you have just installed a fuel pump. I know a lot of you reading  are wondering why I did a write up on this. I’ll explain… you see, I document everything that I do to any car I work on because I can remember what is was like when I first  started working on cars, and what it was like not knowing exactly how to do stuff. For some of you this may seem like a very basic thing to do, and if you’re one of those people then I’m happy for you because you know the basics of working on cars. However there are also many people that aren’t sure how to do this and I want to make sure they can learn how to do it for themselves, and feel the thrill of completing a modification (or even just replacing a bad fuel pump to get their car running again) Because there isn’t a more rewarding feeling in the world than doing something on your car and having it work properly.

Enjoy the read and enjoy the pictures, hopefully even if you’ve done this before you leaned something from this post. As always Thanks so much for reading, and make sure you get out in the garage this weekend and do something to your car. The weather is cooling off and its never been a better time to get out there. You can always ask me any question you might have about this post or anything else by commenting on this post below, Emailing me at Billy@functiontheory.com, or just DM me on Instagram @Functiontheory

 

 

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: