Hi guys..

I'm done with my new build (details below..)

All is set and I'm breaking in the new block for the next few thousand km's...

I have a slight problem though,, the fuel pump no.1 which is connected to ECU wiring (pump no.2 triggers via a boost switch) goes on and off intermittently at idle.. Onlyat idle,, when the car runs normally, my fuel pressure is very stable and rises normally as the boost kicks in..

Of course I had to cut the fuel pump casing to fit both walbros in.. And there's this little wire that I've cancelled that can be some regulator? Is it why the first pump is having this hikcup problem??

Comments appreciated!

Wael

 

Bump Bump!??

Anyone! Help an ailing Evo!


Wael

 

Sounds like a problem with the switch. Why a boost switch btw?

David's double pumper uses a fuel pressure switch since the pressure goes up 1psi per 1 psi of boost you can just trigger on the pump that way once its gets up a ways past the stock 40 or so psi.

 

Tx for reply Spike,

Ya it's exactly what i got, a boost switch that triggers pump-2 when the turbo boost rises above 15psi.. So above 15psi, the two pumps are working, for safety.. Pump-2 is connected external to the ECU wiring, it just triggers on with the boost rise..

The problem I have is with pump-1 only, it just switches on and off (about 2times per second) at idle only..

Wael

 

Ah i see was totally confused there.

what kind of pump is it? If i remember right the Ecu wired pump does this resistance thing lowering the voltage when the pump is at idle. Perhaps that could be the issue and thus the fix would be to connect up pump 1 directly up to the fuel pump relay?

Don't take my word for it though this is just a guess

I would take a volt meter out there and see if something odd's happening to the voltage and work it out from there

 

Exactly,, I know for a fact that there's an ECU 'Low pressure' / 'Hi pressure' ECU order depending on the need..

And i know that pump1 is intermitently shutting off because i can feel it and hear it whininig on and off..

Would it be fair to wire the pump-1 directly on external relay and bypass the ECU?

Wael

 

With your problems i would but first take a volt meter to it maybe its something else

 

OK,, will do tomorrow (it's 1030pm here!)

Thanks.,,

Wael