Hi , we have some issue with an engine and want to be shure above change anything.

Is a F22 non-vtec SOHC fully stock

TD05-16G pumping 10PSi
Skunk2 cam gear -2
DSM 450cc
FPR arospeed
2.5" full ex
2.5" charge

The fuel pump is stock cause we see some builds like this without problems. The filter is new.

In our case, the engine falls lean and the duty cicle is outrated at only 9psi and 5000rpms

We apply 10psi more of fuel and the problem is coming on 10psi and 5500rpms...

Taking account of the estimate hp rating of this engine (little) , i think something is wrong or is possible a fuel pump failure?

I know most proyects start from walbro but i like to understand the problems an use the real necessary parts.

thanks

 

Do you have a way to look the fuel pressure when the engine is under load?

If you see the fuel pressure drop by 5000RPM and 9-10psi then most likely the fuel pump is failed, or is not big enough and needs changed.