s12 in a lotus 7 kit car

[graememk]

well the s12 is in the mk indy replica lotus 7 and the engine running megasquirt but i have a problem, the cars been on the rollers today and its running full fuel but it goes lean above 3800rpm the injecters cant supply enough fuel with the amount of boost (8psi), what do i need to do, as far as i can see its either fit new injectors, change the fuel reg or up the pump, what have others done that run high bhp please

graeme

[umpkin]

8psi is not far from standard, it wouldnt think it should lean out at that boost, mines running 10psi, and as far as i know its not lean (hasnt gone bang in past 8 years ive owned it, although mine has had a small pinking prob of late, i think its more down to type of fuel and timming slightly off, seems to have gotten better since putting in 97RON fuel.

people on here have been running 15psi ish on std fuel, only thing most have is the uprated fuel pressure reg and fuel pump.

im sure they will post soon if im wrong.

hope this helps some, if the RR you used was any good, they should have had some ideas as to the cause and cure.

[graememk]

we only used the rr as a bench mark as they dont know anything about megasquirt, the injectors were just fully open and the engine still ran lean so its a deff a fuel shortage prob, where can i get a different pressure reg from or off ? if changing it do i need to change the rail ?

[s13eater]

i'd say fuel pressure reg or pump, i ran 18psi on a t25 on the std ecu with no probs.

[PukkaSilvia]

what fuel pump has been fitted to the car?

[northerner]

the fuel reg in part of the rail so its a new rail or cut up yours and find an adjustable reg to plumb in

[wacomuk]

Originally Posted by Pukkasilvia

what fuel pump has been fitted to the car?

i would check this first. The standard fuel reg is non adjustable, the fuel pressure rises accordance with the inlet manifold pressure, if the fuel reg isn't receiving correct manifold pressure the fuel pressure will be affected (lower)(idle fuel pressure is 32psi from memory) check for cracked pipes

the standard reg could be past its best, try a FSE adjustable fuel reg or something similar

silviagod has had good results will the cheap jap ebay ones


are you the guy off locostbuilders??

[graememk]

useing the original fuel pump,dont know what psi it is.

[wacomuk]

using the original silvia pump or kitcar pump?

[graememk]

silvia pump, silvia reg and rail and injectors.