Assembly Step 62 PWM idle valve Help Please
Posted: Thu Mar 08, 2012 1:09 pm
So far so good I have completed the test at Step 55 and everything checks out 
. While reading ahead I got hung up on step 62 I dont know if My idle valve is relayed or not? If it is do I need to order more parts to get it setup? How do I need to configure My MS2 V3.0 to get this to work with my setup?
I'm running an 86 SBF 302, Single Turbo, Edis, 36-1 wheel, 60# High Z Injectors,and Stock Throttle Body so whatever Idle contol comes stock is what I'm using.
I have done searches and turned up nothing so this may be a real dumb post sorry Im not the best when it comes to elecrtonics.
62. Install and solder the transistors Q2 and Q4 {ZTX450-ND}. These are located to the left of the MOV1. The side of the transistor with the white label faces the DB37 connector. If you got this transistor from a distributor (as part of a kit) then they likely have special instructions for it (search the packaging or contact the distributor). Distributors sometimes make substitutions for various reasons, and thus their notes are important. If your Q2/Q4 are the standard Digi-Key part {ZTX450-ND}, but don't have a white label, then the side with the rounded edges is the 'curved side', which is oriented to be closest to the DB37 connector.
Be VERY careful soldering these small transistors, clean your soldering iron's tip, and make sure not to bridge the closely spaced pins.
If you use any other transistor other than PN2222AD26ZCT-ND or ZTX450-ND from the MegaSquirt/Digi-Key parts ordering page, you MUST check the pin orientation, as the order can be different for apparently identical parts!
For PWM Idle Valve Users Only
Note - if you are using a PWM idle valve (Ford or Bosch 2 wire valve - see this link for more information), these valves can not be operated with a relay. As a result, they need a higher capacity transistor installed.
DO NOT install Q4 for use with PWM idle valves - it cannot handle the current directly for PWM idle valves. ('On/Off' type idle valves used with a relay are fine with the default Q4.)
Instead, for a PWM idle valve, use a TIP120/121/122 transistor (such as Digi-Key 497-2539-5-ND, 74¢ ea.) mounted on either the heat sink (if you have a spare spot) or the case. You should use a mica insulator (4724K-ND, 93¢) with heat sink grease as well. Run wires to the Q4 connections as shown below:
Do not install Q20, do not install D8, and jumper R39 as well. You will also have to put a 1N4001 diode across the PWM Idle valve itself - the banded end goes to the 12 Volt supply, the non-banded end goes to the lead that goes to MegaSquirt® (this diode is for flyback purposes on the idle valve).
I believe this step is related as well
If you are using PWM Idle control, you cannot use the FIdle relay on the relay board, and have to jumper the relay socket. The jumper goes from the relay socket hole nearest the CB1 polyfuse to the relay socket hole nearest DB37 pin #4.
. While reading ahead I got hung up on step 62 I dont know if My idle valve is relayed or not? If it is do I need to order more parts to get it setup? How do I need to configure My MS2 V3.0 to get this to work with my setup? I'm running an 86 SBF 302, Single Turbo, Edis, 36-1 wheel, 60# High Z Injectors,and Stock Throttle Body so whatever Idle contol comes stock is what I'm using.
I have done searches and turned up nothing so this may be a real dumb post sorry Im not the best when it comes to elecrtonics.
62. Install and solder the transistors Q2 and Q4 {ZTX450-ND}. These are located to the left of the MOV1. The side of the transistor with the white label faces the DB37 connector. If you got this transistor from a distributor (as part of a kit) then they likely have special instructions for it (search the packaging or contact the distributor). Distributors sometimes make substitutions for various reasons, and thus their notes are important. If your Q2/Q4 are the standard Digi-Key part {ZTX450-ND}, but don't have a white label, then the side with the rounded edges is the 'curved side', which is oriented to be closest to the DB37 connector.
Be VERY careful soldering these small transistors, clean your soldering iron's tip, and make sure not to bridge the closely spaced pins.
If you use any other transistor other than PN2222AD26ZCT-ND or ZTX450-ND from the MegaSquirt/Digi-Key parts ordering page, you MUST check the pin orientation, as the order can be different for apparently identical parts!
For PWM Idle Valve Users Only
Note - if you are using a PWM idle valve (Ford or Bosch 2 wire valve - see this link for more information), these valves can not be operated with a relay. As a result, they need a higher capacity transistor installed.
DO NOT install Q4 for use with PWM idle valves - it cannot handle the current directly for PWM idle valves. ('On/Off' type idle valves used with a relay are fine with the default Q4.)
Instead, for a PWM idle valve, use a TIP120/121/122 transistor (such as Digi-Key 497-2539-5-ND, 74¢ ea.) mounted on either the heat sink (if you have a spare spot) or the case. You should use a mica insulator (4724K-ND, 93¢) with heat sink grease as well. Run wires to the Q4 connections as shown below:
Do not install Q20, do not install D8, and jumper R39 as well. You will also have to put a 1N4001 diode across the PWM Idle valve itself - the banded end goes to the 12 Volt supply, the non-banded end goes to the lead that goes to MegaSquirt® (this diode is for flyback purposes on the idle valve).
I believe this step is related as well
If you are using PWM Idle control, you cannot use the FIdle relay on the relay board, and have to jumper the relay socket. The jumper goes from the relay socket hole nearest the CB1 polyfuse to the relay socket hole nearest DB37 pin #4.