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Fuel Pump Upgrade


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#1
CSPCRX

With the upcoming K swap it was time to upgrade my 30 plus year old stock fuel pump to something that can support the 225 whp and 185 ftllbs we plan on seeing. Something the stock pump was never meant to support. The stock pump did a great job of supporting my B16 since 2002, when we put it in. Testament to the quality of the oem parts. Here is what I did and ran into during this process. This may also apply to the Civic SI, not sure how similar the lines are on that compared to the CRX SI

 

So I went with a Walbro GSL392 255LPH inline pump and the Walbro 400-952 installation kit they "claim" allows you to install a GSL series pump in our cars using factory lines. This kit comes with a 12mm adapter for the feed from the tank and a banjo adapter for the output of the pump to the rubber line that connects to the hardline, so you can use all the stock lines.

 

Took the stock pump out, which was fun as these lines have never been removed as far as I know and there is not much room up in there to work. The Walbro pump does fit in the stock pump mounting bracket but not perfectly as the Walbro is a bit narrower. So I used the sleeve the pump came with along with another piece of rubber I had to make up the difference and ensure it stays in place on the pump mount. You have to cut the wiring harness off the stock pump and install ring terminals on the ends so you can install it on the new pump. This makes it plug and play into your harness. Remember the black with yellow is the positive wire.

 

Now is where the kit started to fail me. While the inlet adapter does fit the feed hose perfectly coming out of the tank but there is a problem. The stock pump has a screen, a pre-filter, that slides into the input end of the pump. The 12mm adapter that Walbro provides has an internal opening that is too small to allow this filter to be installed. So now you need a pre-filter and Walbro recommends 20-40 micron pre and 10 micron post for fuel injected engines. Here is what I came up with that worked perfectly and almost exactly followed the path of the stock rubber hose.

1) Walbro adapter 10mx1 to -8an, This threads into the fuel pump inlet side. I used -8an as it is almost identical to our 12mm ID fuel hose coming out of the tank. (part 128-3040)

2) -8an 90 degree fuel filter with 40 micron filter. This threads directly onto the adapter for the pump. I used one from Summit Racing part SUM-220171B

3) -8an 90 degree hose barb. This attaches to the filter and adapts to the stock rubber hose. Again since -8an is so close to the 12mm hose it fits perfectly. I used one from Summit Racing part SUM-260887B

This is all the hardware I used between the tank and pump. I then cut the stock rubber line at a point that lined up with the barb and slid it right on. Used the original hose clamp that was on the hose before. The nice thing is the filter has replacement screens that go in it so in the future I can service it very easily. This setup almost exactly matches the path of the stock rubber line.

 

Now the second place the kit failed me, the outlet side. The banjo adapter they provide is over 1mm to short. When you install the factor line in place with the provided crush washers it will grab two threads and then rip them out. Ask me how I found this out!!!! So now you need to adapt the output side. Here is what I used.

1) Walbro adapter 10mx1 to -6an, this threads into the outlet side of the pump. (part 128-3039)

2) 120 degree -6an hose end, you can use any brand you want I had some XRP hose and ends so that is what I used for this. This threads onto your adapter. Part number for what I used was 212006.

3) You need 5.5 inches of braided -6an hose. I had this already so worked out for me. Making AN braded hoses is not very hard.

4) 180 degree -6an hose end. This completes your hose taking us back to -6an and gets things pointed right at the hard line. Part number for what I used was 218006.

5) 5/16 tube to male -6an adapter. This is what adapts the hard line to an fittings. I had an Earls one laying around so I used it part 165056ERL. This requires you to cut the compression fitting off the end of the hard line. Very easy to do with a small pipe cutter. I cut mine right by the flare so the hard line would be as long as possible.

 

This allowed me to install the pump in the factory location and even put the pump cover back in place. I did have to cut a small portion off of the end where the hard line hit it by the tank. It looks stock if you look in the fender well.. This could be done with any of the GSL pumps. Zero leaks, fired right up and now I have plenty of fuel delivery for the new motor. Hope this helps someone in the future that may look to upgrade their pump.

 


Victor
86 K24 Powered CRX SI (SMF Solo2, HPDE-4 NASA & TA-A Time Attack

85 CRX DX totally original
07 Harley FXST Softail

2021 Tacoma Tow/Daily


#2
anjin

  • redlinefever
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Nice information, thank you.  Did an aftermarket replacement myself without as much drama; major hassel was the replacement being slightly overbig for the cradle.


anjin aka Ian

"I can't believe it - Ive just been passed by a sh!tbox"

#3
CSPCRX

What pump did you use?


Victor
86 K24 Powered CRX SI (SMF Solo2, HPDE-4 NASA & TA-A Time Attack

85 CRX DX totally original
07 Harley FXST Softail

2021 Tacoma Tow/Daily


#4
anjin

  • redlinefever
  • PipPipPipPipPip
    • Group: 2014 Contributor
    • Location:Perth, Western Australia
    • Drives: 83 crx - kakaburra,83 gen1 Noir, 87 EF7 Glasstop crx, 83 gen 1 rebuild replica mugen racecar
    • Image Gallery
    Garage View Garage

Walbro equivalent. Can't recall brand, but it did have one. Went for a metal impeller style rather than plastic, Been great for a number of years. Replaced the oem as my Power FC ecu was showing that I was approaching the maximum duty cycle of the injectors. So I upgraded the injectors and started looking for more power. A pump upgrade was part of the upgrade.


anjin aka Ian

"I can't believe it - Ive just been passed by a sh!tbox"

#5
CSPCRX

Thanks for sharing. Were you able to use the small stock screen pre-filter and all the stock hoses? If so that’s awesome and perhaps you could post up the part number to help others who want to do this, if you have them.

 

if the install kit Walbro sells worked it would not have been an issue. Other than fighting to get the old one out but that was part of it either way. 
 


Victor
86 K24 Powered CRX SI (SMF Solo2, HPDE-4 NASA & TA-A Time Attack

85 CRX DX totally original
07 Harley FXST Softail

2021 Tacoma Tow/Daily