[1funride]

I have one of the original FITECH units and need to change the connector for the orange wire due to the connector being undersized for current draw. I didn’t plan on changing the entire connector just adding a separate connector for the orange wire. Any recommended auto style sealed connectors for just a (single wire – 20A) that folks have used successfully. I don’t want to buy any crazy tools to install a single connector.

With the Walbro pump I have read several posts where it is advisable to turn off or limit the PWM feature (I have a return line installed). Is this really necessary, I don’t like to make changes for the sake of making changes? What are the recommended settings?

[67gtospud]

Just fins yourself a shrink wrap crimp connector and that'll work out just fine.

Definitely turn off the pwm feature on the fitech as it will drastically shorten the lifespan of the walbro pump. Only takes a few seconds and it won't affect driveability or any other settings.

[JLMounce]

I would replace the entire connector. Takes about an hour. I used this.

https://www.amazon.com/Fastronix-Pin...s%2C173&sr=8-5

If you chose to just change the pin for the pump, I'd still use a weatherpack, just get a single circuit.

You want to set your PWM to 100 with the walbro pump.

[Tom Vaught]

Agree, leave it at 100%.

A return fuel line (with a proper Fuel Pressure Regulator) can be your best friend.

The old Boost-a-Pump unit used to add extra voltage to the existing pump to make it run faster for SHORT acceleration blasts, (back in the old 255 liter/hr fuel pump days).
EFI pumps can be had with a lot more flow capability today.


Tom V.

[XLR8STEVE]

I added a relay to my pump. I think 15-20A direct on the Fitech pump orange lead would be pushing it. If you leave the PWM at 100% you can use a standard relay. I just put a 340 lph in tank pump on mine. Draws 16-17A from relay.

[1funride]

I went out to the Walbro web site and gained some additional insight. I "think" many using the Fitech system are using a GPA-4 kit which is a Gerotor pump and Walbro makes it clear that you should not use PWM and to turn it off, and to use a return line.

From Web Site
•These Gerotor style pumps cannot be used with Pulse Width Modulation.
•If using with a FiTech system be sure to turn off PWM.

Walbro does have pumps that are compatible with PWM, these are the kits GPA-5 and higher and flow more. So your pump type may make a difference.

I have the GPA-4, so yes I do need to turn the PWM off,
You all are correct, Walbro suggests to change the PWM/FCC to 100.

Thank you

With regard to the connector I think I'll do what JLMounce suggested and just change out the entire connectors

[JLMounce]

Yes, that's correct, the GPA-4 (walbro 255) is not designed to be sped up, then backed off repeatedly. It technically "can" do it, but it will severely decrease it's service life.

The way the FiTech handles PWM is based on units from 1 to 100, where 100 is always on (100%) and 1 is always off, until the computer commands more fuel. Typically with a PWM compatible pump, you run the PWM at a point where the pump is powered up only enough to provide idle, no load or low load cruise fueling, FiTech recommends a blanket 40% (40 units).

So in the handheld on the system you want to input 100 for the unit count. This will force the computer to run the pump at full all the time. You need to make sure the return line can handle the excess of fuel it will have when the engine is idling or in low load cruise. If you run a -6 or 3/8" line for the feed you want at least that size for the return. Going smaller can cause pressure creep that will overpower the injectors and cause a cyclical surge/stall situation.

[Speargun]

Without PWM, the best way to power the fuel pump is to use a relay triggered by the Fitech. Especially if you have the original type harness with the lighter fuel pump power wire.

[1funride]

I just so happen to have an MSD relay (8960) 1A to activate and 30A load laying around from a project that never happened. I do prefer to not add complexity and have another failure point in series, but it appears this could the lesser of the evils given the original fitech wire gauge and or relay is undersized.