Walbro or AEM Fuel Pump for E85 Application

[Good]

I'm looking to replace my fuel pump and was hoping for some advice as to which fuel pump to use. I'm running a lower ethanol blend and came accross the Radium fuel pump kit.

http://www.radiumauto.com/Fuel-Pump-...6-M3-P314.aspx

I'm not sure how reliable the two aftermarket pumps to choose from are, and if there is another option. There's a AEM and a Walbro unit that supports E85, which I assume have a power advantage over the OE pump.

[heinzboehmer]

This is purely anecdotal, but I replaced my fuel pump with the Walbro F90000274 and had issues starting the car. Seemed like the pressure bled away after sitting for a while. Supposedly earlier versions didn't have a check valve and new ones do? Regardless, the issue was very consistent. Car ran completely fine once started. Let it sit for a couple hours and it would take a couple extra cranks to start. Let it sit overnight and it would take two or three tries to start.

Switched to an AEM 50-1200 and have had no problems since.

I would also suggest getting the submersible tubing, as its hard not to mangle the stock tubing and it's cheap. http://www.radiumauto.com/Submersibl...bing-P672.aspx

[Good]

This is purely anecdotal, but I replaced my fuel pump with the Walbro F90000274 and had issues starting the car. Seemed like the pressure bled away after sitting for a while. Supposedly earlier versions didn't have a check valve and new ones do? Regardless, the issue was very consistent. Car ran completely fine once started. Let it sit for a couple hours and it would take a couple extra cranks to start. Let it sit overnight and it would take two or three tries to start.

Switched to an AEM 50-1200 and have had no problems since.

I would also suggest getting the submersible tubing, as its hard not to mangle the stock tubing and it's cheap. http://www.radiumauto.com/Submersibl...bing-P672.aspx

Do you know which is the correct size?

20-0375 Submersible Fuel Tubing, 5/16in x 6.5in

20-0175 Submersible Fuel Tubing, 5/16in x 12.8in

20-0395 Submersible Fuel Tubing, 3/8in x 6.5in

20-0195 Submersible Fuel Tubing, 3/8in x 12.8in

Thanks for the suggestion!

[heinzboehmer]

20-0175 Submersible Fuel Tubing, 5/16in x 12.8in is what I got for the AEM pump.

[Good]

20-0175 Submersible Fuel Tubing, 5/16in x 12.8in is what I got for the AEM pump.

Perfect! Thank you.

[xpme46m3]

I'm looking to replace my fuel pump and was hoping for some advice as to which fuel pump to use. I'm running a lower ethanol blend and came accross the Radium fuel pump kit.

http://www.radiumauto.com/Fuel-Pump-...6-M3-P314.aspx

I'm not sure how reliable the two aftermarket pumps to choose from are, and if there is another option. There's a AEM and a Walbro unit that supports E85, which I assume have a power advantage over the OE pump.

I have that same kit. not limited to those two fuel pumps listed. I have a Wahlbro one and its been working for the past two years. I have a spare fuel pump since I was having issues initially - turned out to be the wiring.

Any Fuel pump the same size will fit in that sleeve.

[liam821]

I had a Walbro pump in my race car for years without it missing a beat. I recently upgraded to a larger AEM unit, and that also has been flawless. I'd recommend buying from Radium as they make a great bolt-in drama-free kit.

[heinzboehmer]

Yeah might have been an issue with the specific pump I got, but I checked the wiring multiple times, replaced the convoluted tubing, replaced hose clamps and the issue did not go away until I swapped for the AEM pump.

[ethan]

Yeah might have been an issue with the specific pump I got, but I checked the wiring multiple times, replaced the convoluted tubing, replaced hose clamps and the issue did not go away until I swapped for the AEM pump.

I'd been chasing this damn issue for years on two different Walbro GSS342s from Radium in two different M3s. Unless the car hadn't been run for multiple days, cranking wouldn't yield any combustion no matter how long I held the key for, but then as soon as I cycled the key it would fire right up.

I was absolutely convinced the check valves were failing and allowing pressure to drop. Only recently I found that in my case it was the submersible tubing allowing leakage around the barb. Not saying your problem was the same (totally possible you had a bad check valve) - sounds like you'd addressed that line - but that's what did it for me. I'm now using 20-0375 Submersible Fuel Tubing, 5/16in x 6.5in. Same issue in both cars with the OE line (makes sense - things are old and living in gas.)

[DESMDR3]

I’m happy with my AEM 50-1200 pump. Been running it for about 7 months now with the APE flex fuel kit. So far so good, I need to upgrade injectors to really put it to work lol

[i_love_japan]

Have the same kit - Walbro GSS342 255lph for a year now and didn't have any issues with it.

[enjoy_m3]

Bringing this post back up. I just switched to an AEM 50-1200 fuel pump but started to get an issue with the car not starting the first time after sitting for some time but will fire right up the second time. Any suggestions on what to look for diagnosing?

[heinzboehmer]

Bringing this post back up. I just switched to an AEM 50-1200 fuel pump but started to get an issue with the car not starting the first time after sitting for some time but will fire right up the second time. Any suggestions on what to look for diagnosing?

Did you replace the submersible tubing?

[ATB88]

Bringing this post back up. I just switched to an AEM 50-1200 fuel pump but started to get an issue with the car not starting the first time after sitting for some time but will fire right up the second time. Any suggestions on what to look for diagnosing?

Bad check valve bleeding off fuel pressure?

[enjoy_m3]

Hello heinz, yes I did replace the submersible tubing.


Atb88, do you mean the internal check valve inside the pump itself he? Or does the m3 have a replaceable one?