>So you are saying stock injects, with a map voltage greater
>than the 4.5 volts, when as soon as it sees boost pressure,
>the ecu is maxing out the pulse width? (assuming no cut
>device is on the car)By putting on a cut defenser or ML,
>that it keeps the ecu from making the injectors run at max
>pulse width? I guess i just dont understand fully what you
>are trying to say..
>


that is it exactly. when the ecu doesn't see 'max pressure' then the IDC is scalled up just like it woudl be if you were mashing out 140 hp out of the 235's. once you hit boost, the ecu knocks off abotu 5 degrees of timing and basically enriches the crap out of it on a new map. unfortunately, if the long term fuel trim isn't pretty low, teh new map stretches beyond 100% bringing another problem.......fuel cut. it's really 3 different things going on at the same time (at least that is what I gather from foolin around with it). stock map is going at it at probably 80% max duty cycle for non turbo maximum for the stock injectors and stock fuel pressure, then once you hit boost, you go into another pre-defined map........which stretches above 100% idc IF you are at 0% LTFT. at -25%LTFT, the "m.a.p. failure" map doesn't stretch beyond 100% idc anymore, so therefore, the ecu doesn't shut down the injectors. that is why you have to run "stupid" fuel pressure under boost and a fcd to run boost on the stock injectors. that way they won't hit 100% idc (stock fuel map) they won't throw a rich code (stock injectors, relatively stock fuel pressure) and they won't run lean (force feeding fuel through the injectors via pressure per boost).

>>
>What do you mean by this? Does his car barely run at 0-4
>psi?

exactly. it is soooooo rich from 0 to 4 psi between 4000 and 5000 rpm that it won't fire.


>
> after 5 psi, the air/fuel mixture gets into a
>>burnable range, and the car makes power.
>
>By this, i am assuming that he is running fuel pressure
>almost the same at 0-4 psi, as it is under vacumm ?

no. he has a 1:1 fuel pressure regulator with a base (0 pressure) set at 45 psi fuel pressure, so at idle (-7 psi or 14 in.hg) he has 38 or so psi of fuel pressure, and at 0 psi, he has 45 psi fuel, and at 5 psi he has 50 psi of fuel pressure.
>
>
>
>I have the 315cc injectors in my car, and datalogged it to
>fine tune. I run an idle fuel pressure of 25 psi. This keeps
>my short term fuel and long term fuel trims much below the
>-25%, and closer to the stock fuel map. It stays like this
>while normal engine vac driving, and part throttle, closed
>loop, low boost. I was getting around 75psi of fuel at 8 psi
>of boost. EGT's were good, not over 1575. A/F was around
>.93-.94 at WOT in 3rd gear. At ANY idle fuel pressure above
>25 psi, i would get a too rich CEL. Short term fuel trims
>were almost pegged at -25%. So was long term. What are your
>thoughts of this? In your opinion, what is the max boost i
>can run with these injectors? I'm thinking 12-13psi with
>over 100 psi of fuel pressure.

I think you are dead on. I would look into getting some bigger injectors. I know mark's car hit around 100 psi of fuel pressure with the 440 cc injectors at 20 psi (it was just a spike, but air/fuel ratio was still right where it was supposed to be. that s-fmu rocks). don't worry about running too low of fuel pressure. as long as yoru car runs, you are in the clear . mark's car idles perfectly at 10 psi of fuel pressure just to give you a hint . we logged it at the dyno, and I was like "wtf..........ok. that's new". the 420A is a neat little engine, and is pretty different from most things......that suck


>
>
>>
>>A.D.P.
>>"...If you do too much, people become dependant. If you do
>>to little, people loose hope. If you do it right, people
>>won't be sure you've done anything at all."
>>bring it on............

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............

A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on...........