Mike Bones

In the above picture (post #6) with the blue relays installed, there are 2 blue relays side by side. The one on the left is the fuel pump relay. The one on the right is for the starter.

EvoX-11

iTrader: (7)

well according to this explanation, mine is black.

Should I get a blue one?

Is this the one to get?
http://www.amsperformance.com/cart/m...ump-relay.html

mlomker

iTrader: (1)

I can't believe that people are spending $13 on a single relay. For many years owners of older Mitsus have been rewiring their fuel pumps to run directly off of the battery using a $3 Bosch automotive relay and some wire. The battery is only a couple feet away from the fuel pump so it's not much work.

To answer your question, yup, that's the one.

EvoX-11

iTrader: (7)

Oh thats a great idea since the battery is located in the trunk but requires more labor/work vs plugging a relay and be done with it

mlomker

iTrader: (1)

That's the problem, bro...they're never done with these threads. With the pump running at 9-10volts by default it is a time bomb waiting to happen. A Bosch relay either works or it doesn't. It's either at alternator/battery voltage or it's dead. It's a lot safer.

EvoX-11

iTrader: (7)

Wait I am lil confused...

Switching the relay is a lot safer? Is that what you mean?

clc3667

iTrader: (1)

I don't know about safer but it is definately easier. It takes literally like 3 seconds once you have the new one and keeps an OEM look as well with out adding new wires. I wasn't sure on mine so I jsut replaced it so I didn't have to worry about it.

mlomker

iTrader: (1)

I meant that ignoring the car's relay is a lot safer. Anyone that has installed an inline fuel pump has installed a Bosch automotive relay before. They cost about $3.

Here's the wiring diagram:


You'd cut the power lead going into the pump housing (it's a blue wire on my car). The side from the car goes to 86 -- this is the turn-on wire. It won't matter if it is 9volts (a failed relay in the engine bay) or a higher voltage...it'll still flip the relay.

#87 goes to the cut wire into the pump housing.

#30 is a new wire with an inline fuse to the positive terminal on your battery.

#85 is a new ground wire run to the battery area (there's an open bolt hole next to where the battery's negative terminal connects to the chassis, perfect for grounding your own stuff).

Relay + wiring pigtail + inline fuse + a few feet of 14 gauge wire = $15 tops.

For the cost of one replacement relay (that may fail anyway) you could make it impossible for your pump to ever see 9 volts.

Possible downsides: you may be a little rich in the lower rpms until you are retuned. The pump will be more audible at idle since it's running faster. DSM and older Evo owners have been doing this 'mod' for many years to solve issues with small gauge/poor wiring.