A question about fuel injection

[rabbitman]

So I started wondering what happens when the go pedal is floored.

Does the start and stop of injection always happen at the same spot on the camplate regardless of pedal position/rpm? So that the injection "window" stays the same but the quantity changes.

Or does it always start in the same place and end sooner or later depending on pedal position/governor? This is what I'm leaning towards.

I started wondering this because (assuming timing effects boost a lot) I've been noticing my boost will sit at about 6psi with the go pedal 1/4" off the floor at about 3500rpm, if I floor it the boost climbs to 10psi very quickly.
If I try to let off and only loose 1-2psi, it drops back to 5-6psi, like it's very jumpy.

During all this the EGT's stay right around 1200-1250F, and the maddening vanes are about a third closed.

Does this jumpyness sound normal? (except for the pitiful low boost )

So this is my big question, does flooring the pedal kinda get the fuel injection time into the turbos happy spot?

Sorry I'm so longwinded

[burn_your_money]

Nevermind, I don't know what I am talking about

[smutts]

Or does it always start in the same place and end sooner or later depending on pedal position/governor? This is what I'm leaning towards

Well that's what I believe.

if I floor it the boost climbs to 10psi very quickly.
If I try to let off and only loose 1-2psi, it drops back to 5-6psi, like it's very jumpy.

Boost depends on how much exhaust is blowing through the turbine, more revs, more fuel, more boost. More boost, the LDV thingy (Starship Enterprise thingy) on the pump pushes in more fuel, more boost. So, weird things seem to be going on till your foot hardwires itself to allowing for this.

The boost fuel synergy thing does make driving on ice and snow bit of a pain in the arse.

[burn_your_money]

I'll try again.

Start of delivery varies according to the movement of the advance piston which is related to internal pump pressure.

End of delivery varies based on where the collar on the plunger is, which is determined by engine RPM and throttle position.

[rabbitman]

Or does it always start in the same place and end sooner or later depending on pedal position/governor? This is what I'm leaning towards

Well that's what I believe.

if I floor it the boost climbs to 10psi very quickly.
If I try to let off and only loose 1-2psi, it drops back to 5-6psi, like it's very jumpy.

Boost depends on how much exhaust is blowing through the turbine, more revs, more fuel, more boost. More boost, the LDV thingy (Starship Enterprise thingy) on the pump pushes in more fuel, more boost. So, weird things seem to be going on till your foot hardwires itself to allowing for this.

The boost fuel synergy thing does make driving on ice and snow bit of a pain in the arse.

I don't have a LDA so my foot governs most of everything.