[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: Fuel injection questions
> In message <199704201656.JAA20188@gonzo.wolfenet.com> orin@WOLFENET.com writes:
> > > a) I used the on-board diagnostics to run the fuel pump and warm-up valve.
> > > Then I applied vacuum to the pressure regulator. The fuel pump noise
> > > rose in pitch, quite noticably.
> > Careful doing tests running the fuel pump by on-board diagnostics - there
> > is some funny code in the MAC11 computer at least - I think it cycles
> > the power to the fuel pump at a 50% duty cycle.
> Not on the MAC12. The pump is powered via the relay, and the relay is
> held hard over.
The MAC11 powers it by a relay too. I'll take another look at the code.
> > Ah, but what happens when you apply pressure to it? One would expect an
> > increase in system pressure in this case.
> It never sees pressure in operation - it's hooked to the air mass sensor
> plenum chamber.
> > BTW, for us US types, what is the spec for HP and max boost for your car?
> 200bhp stock. Maximum boost is something like 7 or 8 psi. I'll check
> and post a note later.
Thanks. What's the compression ratio? From ScottM's post later, it sounds
like your car is very similar to his...
As for computers, so far, it seems the MAC12 is a slightly stripped down MAC11
(no O2 sensor input or charcoal canister output) and the MAC14 which
Scott has is the dual knock sensor evolution of the MAC11.