AC STAG-4 QBOX BASIC User Manual page 30

 Injectors heating – check to enable warming up gas injectors when vehicle was parked a
longer time at freezing temperatures. Active procedure is marked with a red line displayed
on the oscilloscope screen and with blinking gas injector icon in the parameters monitor
window.
Petrol portion – a set of options to allow automatic modification of petrol share map so

that: for rpm higher than the value set in the "minimum rpm" field and injection pulses
longer than the value set in the "minimum petrol injection time" field, gas injection will be
supported with petrol injection pulse equal to the value of the "petrol adding time" field.
 Pressure release – in the course of driving, when gas injectors are not controlled (e.g. in
the cut-off status), gas pressure in the gas controller may rise. If this option is on, when
pressure exceeds the set value (Switch-over threshold), the controller will start a
procedure to bring it down. The procedure is switched off when the pressure drops down
to 1.5 bar. Pulse frequency parameter controls the frequency of the injectors opening.
 Leaning on cold engine – the cold leaning option allows eliminating the effect of jerking
as a result of gas overflowing to the cold engine. The problem occurs in certain vehicle
models. If necessary, set the parameters as follows:
Max. engine temperature threshold should be close to the engine temperature, at
which jerking stops.
NOTE: Engine temperature threshold influences the time of function operation.
Always note if the ratio represents a rich fuel mixture for the warmed engine
under high load. Failure to follow this note may result in engine damage!
Max. rpm threshold should be set by experience so that there is no power drop under
maximum acceleration at higher rpm and there is a rich air-to-fuel mixture in open
loop conditions.
Max. gas injection time is set when driving on cold engine so that sudden pressing of
the acceleration pedal does not cause jerking, while keeping the maximum dynamic
performance of the vehicle,
 Cold VAG – an option that is particularly useful in cars of VAG Group (but not only) with
long petrol injection pulses on clod engine, which results in flooding and jerking the engine
while accelerating and running on gas. This function is activated only for a short period
after detection of the increase in the vacuum. Setting:
Active – Function VAG is on, if checked
Sensitivity - Minimum required increase of pressure in vacuum (MAP), which will lead
to the activation of the function, if the value is higher than the sensitivity is lower. This
value is set experimentally so that while during stable driving function is not activated,
in example:. If at that time the MAP changes within ± 2, sensitivity should be higher
than 4.
Maximum engine temperature – Threshold of engine temperature while without VAG,
jerking stops.
Status – values to be chosen "OK" or "no data". Information about numbers of data
necessary to proper working of function. Function collects (learns) data while driving
on petrol on warm engine.
 Switch off the solenoid – When selected, the gas solenoid valve is closed if ISA3
switches to petrol. The option is helpful when using a timing advance processor (TAP).
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