So I’ve successfully replaced the fuel pump in my old (s1) 2004 GT with a Deutchwerks DW200 255lph high flow fuel pump. I only needed slight modifications IE melting the pop off. While everything I’ve heard has always been that the s2 sending units didn’t need any modifications and that most people preferred the Walbro over the Deutchwerks. In the few posts I was able to find around the internet, I found that the GSS341 seemed to be the model of Walbro most often mentioned with the RX8 , so I ordered one. It was too long, too fat and the strainer was on the wrong side. So I ordered a GSS342 , but that only solved the issue with the strainer. I decided to force it into The filter where it’s housed in the s2 sending unit and it was indeed a rediculously tight fit. Plus with it being so much longer, there was no way to snap on the strainer bracket. Then I also had to force down the 3 locking tabs that secure the filter holding the pump to the rest of the sending unit. So if you’re having trouble picturing this, just know that everything is back where it goes, but it’s all forced together. I Try to start the car and nothing…. It kinda sounds like it starts for a brief second, but that’s it. I tried this with the GSS341 and a GSS342. I put my old OEM pump back in and it started right up.
I’m currently in a holding pattern waiting to hear from someone who has installed one of these in an S2 to advise me before I return both of these fuel pumps. Any insight would be greatly appreciated.

 

I have a 2011 and when my fuel pump died, I ordered the DW65C fuel pump kit with the strainer and O-rings. While the pump itself was just a fraction of a mm off rotation compared to the stock pump, I was able to fit it into the filter and sealed everything up. I did not attempt to modify the pressure relief for the fuel return, and simply replaced the whole assembly back into my car. After filling the tank up a few gallons and priming the pump, my car started up without any issue and I have not had to do anything with my fuel system since. I did not verify the fuel pressure with a pressure sender like I should have, but I had no loss of power, misfires, or any indication of the fuel pressure being inadequate after the installation.

If you are having issues with your aftermarket fuel pump, verify that when 12V is applied that you can hear the whir of the pump and that something is flowing. While it's not recommended to test a pump when it's dry, you can probably just shunt 12V to ground with the pump out and check if the pump does anything for a brief moment. If not, then your pump is defective.

I would assume you primed the pump before trying to engage the starter when you installed the pumps, as you say you didn't have issue restarting with the OEM dropped back in. I primed my pump by just KOFFKON five times until the sound was lower and quieter. The DW pump has a limited warranty on it too, I believe it was 4 years or something.

 

I forgot to mention that the O-Rings should be lubed lightly and have a tight fit between the pump neck and the fuel filter. If not, fuel can just flow back down to the bottom of the pump instead of going up and I to the fuel line. If this O-ring was not installed correctly, you may have a loss of pressure.

 

Your post is confusing, are you installing a DW or Walbro pump? A DW200 works perfectly for basically 100% of Rx8 setups, exceptions being things like boosted setups. And where are you ordering these pumps from, are you sure you are getting a genuine product??

Finally, DW does NOT show compatibility of their DW200 pump (or DW300 pump) with a S2 Fuel basket on their website. Only S1 Rx8.

 

you likely won’t be surprised to learn that the same thread was posted twice in two different forum areas then

https://www.rx8club.com/series-ii-af...3/#post4969422


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I mean, they may not show compatibility but it's compatible. I'm running a DW pump!

 

the 2009+ S2 fuel pump module uses an entirely different brand/size pump than the 2004-2008 S1 module.

https://www.rx8club.com/series-ii-af...3/#post4969422
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