Boost control mod kit

Boost control mod kit

Kit contains:

• TIP122 transistor
• Mica insulator
• 100Ω resistor
• 10kΩ resistor
• Heat sink grease

All needed parts to control 2-wire PWM idle valve.  Can be used with both V2.2 and V3.0 PCB. 

V3.0 Installation:

Don't install Q4 transistor or remove it.  IRLZ44N in kit can be installed in place of Q16, that is usually left empty.  Or you can bolt it into case.  Important is to connect IRLZ44N into heat dispatching surface using Mica insulator and heat sink grease.

Also don't install Q20 and D8.  Leave R39 out too and jumper it with resistor or diode leg or similar 

1N4001 diode should be installed between right side hole of D8 and banded end on S12 hole.  S12 is found bit above processor.  That diode is for flyback purposes 

+12V for valve should be taken from fuel pump relay.

V2.2 installation:

Replace transistor Q5 with IRLZ44N.  Best way is to attach IRLZ44N to casing with Mica insulator and heat sink grease. 

1N4001 diode should be installed between idle valve wires.  Banded end on +12V and non-banded end at pulsed grounding wire that goes to MegaSquirt. That diode is for flyback purposes 

+12V for valve should be taken from fuel pump relay.

Schematics is directly from MegaSquirt I, but same one works with other processors / daughterboards too.  http://www.msextra.com/doc/ms1...

MegaSquirt II possible output pins:

• JS11
• Fidle
• IAC1
• IAC2

MegaSquirt III possible output pins without MS3X board:

• IAC1
• IAC2
• Fidle
• JS11
• JS10