Rocking Rotary

iTrader: (14)

Hello,
I have been trying to have my rich running condition taken out of my car and finally the problem has been tracked down. It is my fuel pump flowing 60psi at idel. I have a walbro in it and was thinking of going to the Supra denso pump.
So I was wondering what would you guys do? I have the old pump and the wires I had to cut to install the walbro.

Has anyone else done this, also are the walbros really that bad? The thing was only ran for 4 months before this happened.

carbon man

what ECU do you use?
it is dangerous to just change the fuel system without re-tuning to the change.
Do you log the air/fuel ratio?
What was the fuel pressure before you changed the pump?
The fuel pressure should increase by the same amount as the boost pressure when you get on boost, is this happening?
What are you using for a fuel pressure regulator?

Ian.

Rocking Rotary

iTrader: (14)

I have a power FC and useing stock every thing else. Except injectors. 1200 and 550. I did switch secondary rails and 850 injectors but everything else was the same. Same rich condition I mean. As for a/f ratios hasn't even ran to be tuned becouse it was spitting fire out the exhaust at idel.

I was just wondering on the switch of the pump ?

carbon man

the fuel pump should not control the fuel pressure, your fuel pressure regulator does that. You need to reduce the pulse width on the injectors to reduce the fuel at idle if it is too rich. If you have put larger injectors you will get more fuel each cycle and the engine will be rich. I am not familiar with the power FC so I can't advise you on tuning it, But changing the fuel pump should make no difference to the tune unless it will not deliver enough fuel and the engine will then run lean.

Ian,

Rocking Rotary

iTrader: (14)

I replaced the secondary rail with another one I have and it does the same thing. Plus the person who said it is the pump works at a supporting vendor.

carbon man

you could change the pump and if that does not fix your problem then change the fuel metering at the ECU till the engine runs corectly. I think 60psi is the correct fuel pressre, some injectors that use the fuel pressure to close the injector and the internal coil to open them will run leaner if you apply higher fuel pressure than they are designed to run at. What fuel pressure did you run the last time the engine was tuned?

Ian

Rocking Rotary

iTrader: (14)

30-35psi base all the stock fuel stuff.