Running Lean!

[stuartlaw_78]

I am rebuilding my rb25det engine and took the turbo in to someone today... He looked at it and said it was stuffed.. had a lot of play in it...

We looked in the exaust chamber and it is all white!!! They are normally black from excess fuel...

This is running lean as!! It makes the car run really well but I'm nervous!

It's running stock ECU.... maybe the fuel pump is dodgy?!?!

Anyone know what would caus this?

Bad injectors??

[Messiah]

Could be a number of things.

First and for most is it a stock or uprated turbo.

On a stocker i'd be surprised if you maxed the injectors.

I run a rb25 with stock turbo and no fmic at 12psi (playing it safe boost wise) and a pfc and i only get an injector duty cycle of around 60 - 75%.

The fuel pump is definately a possibilty, when i first dyno'd my car the factory item had almost totally died, it pumped enough fuel to run... but a big ZERO was coming back the return pipe. So if yours is still factory check that out.

There is a test procedure that ppl do when they dyno a car, i'm un sure of the specifics but its generally a matter of disconnecting the return line from the fuel rail to check the pump, after that i'd imagine they'd use a wide band lamda probe to read the mix post injection, maybe doing some similar tests might help u find the root cause.

Edited December 2, 2005 by Messiah