c20let leaning off on boost

[torquey]

Can any one help my let nova is leaning off according to the wideband on boost. When giving it some it goes to near 17.0 on the wideband. Engine is eds phase 2 running saab reds set at 3 bar with vac pipe removed and blocked. Boost is running around 10 psi. Any help would be great.

[meritlover]

fuel pump, filter, regulator or vac line between the plenum and the FPR. If the FPR isnt increasing fuel pressure proportionally to the manifold pressure, then it will run lean.

either that or its not a genuine reading, could have exhaust leaks, or a missfire.

[torquey]

Fuel pump is new as is the filter all vac lines have been redone its running a cossie webber reg dont think i have any exhaust leaks but will check cheers.

[meritlover]

.... running saab reds set at 3 bar with vac pipe removed and blocked.

there's ya problem

[torquey]

What should it be then ??

[meritlover]

the FPR should be plumbed into the plenum so the MAP ref can be used. this keeps the 3bar DP between the plenum and the fuel pressure. for instance with it plugged your pressure is 3bar. if you pull 1 bar of vac (for eg) you will have the equivelant of 4bar fuel pressure. conversely, at 10psi boost you will loose nearly (1bar=14.7psi) 1bar of fuel pressure and will only be supplying the fuel rail with 2Bar (relative to MAP). To prove a point at an exterme, if you were to run 3bar of boost and fuel pressure of 3Bar you would get 0 flow out of the injectors.

run a vac hose between the FPR and the plenum (downstream of the TB) and it should stop it over fueling at vac conditions and underfueling on boost.

[torquey]

Right ok will give this ago then i know what your saying thanks for the info.

[torquey]

Can i tee it off the side of the tb where the map sensor pipe comes off or not?

[Nick J]

Im unsure of the pressure required for phase two when using sabb injectors but I know its 3.5 bar when using stock yellows on the c20let. Pretty sure you want to be aiming for the wideband to be in the 11's though when on boost. It may be an idea to have it setup properly by a company that knows what their doing as if that wideband figure is correct your going to do damage if you continue to run it like that as obviously somethings a miss.

Nick.

[meritlover]

Can i tee it off the side of the tb where the map sensor pipe comes off or not?

yes, but surely there is an original place for it to be fitted. i would doubt that it was T'd into the MAP sensor when it came out the factory.