The Evolution is a terrific platform to modify under any circumstances, but when enthusiasts turn up the boost or add more power they will need to dial up the fuel as well. Today we’ll be installing a DeatschWerks DW300 Fuel Pump, part number 9-301-0847. This pump is a 320lph unit, which is significantly higher than the standard 255hp upgrade from Walbro or BBK and puts the fuel flow along the same lines as a Toyota Supra’s factory Denso unit.
You will need a fuel pressure regulator after this modification to help lower the fuel pressure at idle. Excessive fuel pressure at idle will cause an overly rich condition and with this 320lph fuel pump, can lead to fouled spark plugs and diminished performance.
Like most DSM’s and other imports the Evo fuel tank is located under the passenger side seat panel, and this saddle type fuel tank holds TWO fuel level senders. First locate the tabs under your front seat and pull them forward which will allow you to remove the lower seat panel and expose the chassis and access panels. These tabs are located between the sides of the seat where the bottom meets the carpet, simply grab and pull forward until you hear a click.
*** NOTE – You are best served while doing this on an empty tank or near empty tank of gas as that will allow you to limit the mess and limit chances of an accident.
Once your back seat is removed, take a look at the access panel behind the drivers seat held on by 4 phillips screws. Unscrew each and remove the panel to access your fuel pump assembly, and make sure to do the driver side!
Now with the access panel removed, now is a good time to go and open your fuel door and unscrew your gas tank cap. Once you are done there, go and unplug the electronic harness that controls the fuel pump.
There are 3 hoses and 2 of them are by pushway connectors, remove both the high pressure and suction hose end quick connects by squeezing the tabs inward and pulling off both lines. As the assembly and lines are plastic, take care as to not use excessive force and break something in the assembly, the line or the pickup tubes.
Next, the (6) 8mm nuts that hold the assembly in place must be removed by way of extension or ratchet, however the front 2 nuts will require you to either cut or bend back ( peel back ) the sheet metal. We recommend you peeling back the sheet metal EVER SO GENTLY as to give you the extra wiggle to undo these fronts.
The most difficult part of this install is up next as we must get the entire assembly out without damaging anything. We recommend you turn and rotate the assembly as best you can, but we NEVER recommend cutting or modifying the lines, the chassis or the nipples to get your fuel pump assembly out.
Cutting these lines to get the assembly out is both dangerous and not recommended. You are dealing with high pressure fuel lines and a slight leak or problem with your “modified” line can cause a fire, an explosion or both. It’s not worth it and not needed to perform this install.
Once your assembly is out try and find a nice safe place that you can have the remainder of the fuel leak out and be cleaned up safely.
The fuel pump retainer is the lower portion of this assembly and is removed easily by popping the 3 tabs at the bottom by hand or with a screwdriver. Once the retainer is removed, you can see the factory pump, pickup, rubber isolator and orings.
Remove the factory unit and assemble the new fuel filter ( or fuel sock ) onto your new pump and secure using the oring provided in your package. Once this is done, make sure to slide the orings up and over the pickup unit and replace the old fuel pump with the new Deatschwerks pump.
Take care as to not pinch or get any of the wires bunched up when you slide the fuel pump into your assembly. Once the outlet is near the top look through the side to line up the pickup with your assembly pickup tube.
Now you are ready to put back the fuel pump assembly, make sure the large oring on top of this assembly is there before installing back into your Evo. If you are a smart cookie, you will have remembered the difficulty when you removed the assembly in the first place, take your time and reinstall the unit in backward order.
Now that you have your assembly and ring back in the properly aligned position, tighten the 8mm nuts in a criss cross pattern and torque each one to 23 in/lbs. Snap the pressure hose and suction hoses back in place with your quick connects and slide the third hose over and secure with the clamp.
Now that your Evolution 8 fuel pump is installed, you can now get back to having some fun! It may take a few cranks before your Evo is ready to go, and please make sure to make any changes to your tuning at this time.
Happy boosting!
Written by StockSpyder
- Pro Street Online
- www.prostreetonline.com
- 1-888-776-7022
Is it necessary to add an external relay to keep a constant 12V to the fuel pump … Or not the case ?
Hi Ryan, thanks for commenting.
We’ll be dusting off the How To for wiring in a fuel pump relay, but its not needed. When you are working on your fuel pump however, it’s always a good idea to rewire for the constant voltage, and use a relay each and every time to prevent fires or other electrical issues.
Thanks for reading, we’ll post up the How to behind the fuel pump relay shortly.
Ryan, here’s that article we promised. Hope it sheds some light on your project!
http://my.prostreetonline.com/2014/12/02/rewire-fuel-pump/