Problem with the fuel pump?

[Itsuki]

Hi,

I've setup a FN2 with a Rotrex C-30, RRC intake manifold, Tial BOV, Spoon Throttle, IC, Toda headers, 3" custom exhaust, Skunk racing fuel rail and Walbro fuel pump.

When the car it's on WOT, and it's on open loop reading the tables, when the VTEC it's engaged, the car goes lean. I've added fuel to compensate, but still gets lean. I've added a lot of more fuel (very high ridiculous values!) but it's the same.

The injectors are 1000cc from ID. And if you see the datalog, the duty is reaching almost 100%, so it doesn't make sense with this setup, that can't give enough fuel from the injectors. I had setup the dead time from their specs, and also added later some more miliseconds to try it (I read this suggestion from Hondata in the forum).

Also, you can see that the car gets some boost, so I think it could be discarded any leak from the intake section.

I'm pointing to the fuel pump. I must check if has any problem or is not a real "Walbro". But before buying a fuel gauge to check the pressure, I want only to confirm if you see anything wrong with the calibration and the datalog (besides the fuel value :-S ), only to discard it.

Thanks for your help!

[nunoctr]

your 02 sensor is dead and went to sensor heaven.
If you add fuel and it's still reads lean this is the cause.

[Itsuki]

That's a good point, but I also have a AEM Wideband installed, reading the same values (the AEM a little bit leaner than the OEM). Do you think they went to the sensor's heaven together?

[nunoctr]

Don't know but this was what I had. The car was lean and 100 duty cycle. After changing the sensor the car was realy rich in reality.

[Itsuki]

Yes, I think it could be possible. But if you take a look in my datalogs, when the car is in closed loop, the O2 sensor reads rich values, and also in WOT when the VTEC it's not engaged.

Hope today I can test the fuel pressure, but just to discard any fault in the calibration.

Thanks for your help.

[Itsuki]

Solved!!

It was the Walbro fuel pump, that wasn't fit properly. We tested it and it was working at the 25% of the pressure expected. Now it works fine with the trimming of the pump. The car runs really smooth now with a realistic calibration.

Thanks for your help, Nuno!!

[nunoctr]

I am very happy it's solved. We need some strong fn2!