Hi, im trying to diagnose a problem with my SC setup - https://www.s2ki.com/forums/index.php?showtopic=779125

My friend says the walbro fuel pump should be around the same voltage as the battery when idling?

We have found the fuel pump voltage is quite alot lower than the battery (its about 12volts battery is quite a bit highier) and believe in WOT it cant cope to give more fuel to due lack in voltage.

Can anyone confirm this?

Thanks

 

I've seen several threads on this topic.

Lots of people choose to re-wire the pump or use a BAP

https://www.s2ki.com/forums/index.php?showtopic=778611

There are many possible problems that you could be having or a mixture or all.

-pump failing, usually pumps don't just lock up/ seize, they tend to get "tired" and their flow output decreases over time - that leads to a lean condition

Solution, replace it, $100 buys you a brand new Walbro.

-low voltage, the pump may not be getting enough juice.

Solutions, re-wire the pump and/or use a $240 device called Kenne Bell Boost-A-Pump

On your thread, a lot of good suggestions, larger injectors, check the rising-rate FPR,

 

If the pump is only seeing 12v with the engine running you might try wiring a deticated relay just for the fuel pump. In all cases that I have done this the fuel pump voltage is with in 0.1v of battery voltage with the relay installed.