2G Fuel Pump Rewire with 3 way Switch?

[GIB]

2g GSX, Walbro 255 HD, 1150 injectors, LINKG4X
40 Amp 5 pin Relay
40 Amp inline Fuse
3-way Switch, on-off-on

PLEASE SEE PHOTO ALSO

? Can I wire a 3-way switch to prime the pump-ON, turn off pump-OFF, and run like normal-ON?

? If yes, then how is it best wired w/ a 3 way switch?

I'm doing the fuel pump rewire tonight and would like to know if this is possible.

Thanks.

You must be logged in to view this image or video.

 

[Tiki2777]

I don't understand WHY you want a manual on switch for the pump, you have Link.....does Link not offer a digital interface to run the pump?
Or are you just set on having a manual prime, bypassing the key?

 

[GIB]

I'm trying to set a manual prime, yes.
The pump does prime at key on, but still not enough to start with one crank.
I still need to learn how to use link.
? Do you have a tuner that can make it start on one crank on LinkG4X?

 

[Tiki2777]

I'm trying to set a manual prime, yes.
The pump does prime at key on, but still not enough to start with one crank.
I still need to learn how to use link.
? Do you have a tuner that can make it start on one crank on LinkG4X?

Hmm, your description makes me think you should consider a couple things:
1, Your tune may need to be revisited, since this is a starting issue.
2, How do you know that extra "priming" will net you anything period? Your pump is simply going to be running for longer prior to cranking, and the pressure regulator is going to be returning the same volume of fuel it's been returning even if it was primed for a half second, vs. 60 seconds. UNLESS your tune already has a timed fuel pump prime, and you let it sit before starting?

Some ECUs have options to push/pull fuel for cranking. I know very little of Link.

 

[GIB]

When I turn the key on, I hear the fuel pump going. I thought this was a priming.
I have a green top cas, and thought that it doesn't push fuel until cranking like the 1g.

I don't know what the extra priming will net. I'm just trying to find a remedy for having to crank the car several times before starting. The tuner was stumped.
I mentioned setting a manual prime switch to help it start and he agreed that I could try that.

It's a real pain to use this car only because of the starting issue.

 

[steve]

On a 2G the fuel pump is driven by ECU software. Since you have a LinkG4X it's their software that decides what happens not what Mitsubishi's did. On both generations Mitsubishi looks for signals that the engine it rotating to turn the pump on via the ECU. On a 1G it's the CAS on a 2G I don't know it it's the crank or cam sensor that the software is using.

On a 1G, the fuel pump gets turned on by either the ECU (by grounding the first coil in the MPI fuel pump relay) or the ignition switch being in the Start position (12v going to the second coil in the MPI fuel pump relay)

If you fuel system can't come up to pressure in a fraction of a second there is something funky going on. It's not like it's filling a garden hose.

I should add this works this way so that the pump turns off if the engine stops which helps keep you from burning up in an accident.

 

[jdxnc]

Ecmlink can be set to prime the pump up to 30 seconds on its own, no need for a manual switch.

 

[GIB]

Should I still perform the rewire mod then?
(Running power from the battery directly through a relay)

 

[jdxnc]

Should I still perform the rewire mod then?
(Running power from the battery directly through a relay)

The rewire is always a good mod to do for better voltage at the pump.

 

[GIB]

Thank You. I will contact the Tuner.
Do you all know a good tuner that can remote tune this, just in case?

 

[We're on Boost]

It sounds to me like you need something that works like 'Cranking Fuel Adjust' in ECMlink.
It starts throwing in a lot of extra fuel as soon as you start cranking.
As soon as the engine starts running, the extra amount starts to reduce.
On my car, the extra amount is down to zero after 17 seconds from when I started cranking.
The initial amount of extra fuel that it throws in is set according to coolant temperature, in a table that looks like this:

You must be logged in to view this image or video.

Maybe your setup needs some prime time for some reason, but my Walbro 255 doesn't need it. I just need Cranking Fuel Adjust. I know because for about a year I didn't have it!