MSefi.com read only forum (Jan.15,2018)

Hi,

I cant get a definate answer on this and dont want to bugger things up so here goes.

I have fitted larger injectors to my rebuilt engine im running MS1 Extra.

Do I just have to change the req fuel for the new injector settings only??

Or do I have to go in and under one of the options saw something about old req fuel and new req fuel and this changes the VE tables.

I understand it will need final tuning but just want to get roughly somewhere so I can run a few miles in.

Many Thanks

Neal

You need to change Required Fuel, Cranking Pulse Width, and Acceleration Enrichment. Maybe Injector Opening Time too. The rest is unchanged.

I have also changed from 2.5 bar to 3.0 fuel pressure, is there a calculation to allow for this or will it still be in a good range to get it running in??

Engine is a rover v8 old injectors at 3 bar were 210cc / min but were running only 2.5 bar for my req fuel calculation.

My new injectors are 350cc / min at 3bar which I now have with a new fuel pressure regulator.

Flow increase through a fixed orifice is a function of the square root of increased differential pressure; Q2^2 ~ Q1^2 x (P2/P1)

You've increased your dP by (3/2.5) = 1.2; your flow will increase by a factor of 1.095.

This is theoretical math, real world factors in your piping will also contribute with minor flow losses.