looking at the pic.

bottom leg goes to ground, middle leg goes to idle valve, top leg goes to input from cpu.

you should put a 1n44 diode on the with leg to 12v, banded end on 12v.

you refering to the IAC mod?

Just making sure

si. on the middle leg is what i meant to say about the diode. i assume the tip120 on the case is the driver correct?

Its a NTE261 they said its a direct replacment\compatible to the TIP120

you sure that diode isn't for pcb v3 layout?

pcb v1.01 has the diode D9 as a 1n4001 connect to that leg already on installed.

aiight, it's just for extra flyback protection.

good to hear

http://a.imageshack.us/img689/9253/v...0209h53m41.png

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only 20 more to go!

Does the fuel pump get activated by the 12v output from the ecu?

no, on a 1.6L car what you should do is build a high side driver circuit.

http://www.diyautotune.com/diypnp/images/vtec_lg.gif

Use one of the TIP125s that you don't use (the ones with MICA q12 and q9 or whatever they are).

Basically you'll want to take the FP output (banded end of d4) through the 220ohm resistor to the TIP125, you skip the part of the circuit prior to that because you are using Q2/Q19 for this.

get the 12v source from s12c or s12 or banded end of d9.

then the vtec_out should go to 1C on your harness. YOU MUST REMOVE THE ST_SIG FUSE UNDER THE HOOD.

LAMENT TERMS: when the MS grounds the fuel pump, you are instead sending 12v out to 1C, which back-feeds the fuel pump relay and activates the circuit. you must remove the fuse or you will ruin the circuit.


or, you can take the fuel pump ground out your harness, run it across your dash and attach it to the ground on the fuel pump relay itself.

LAMENT TERMS: When the MS tries to ground the fuel pump relay, you acutally ground the fuel pump relay.




if you keep the AFM in place the AFM grounds the fuel pump relay.

I'm not quite sure how that circuit is supposed to work. That PNP darlington is backwards.


EDIT: Just looked up the datasheet on the TIP125. The pin numbers are correct, but the symbol is flipped (collector/emitter) in the schematic above.

oh. i didnt draw that.

looking at it from above:
-o
[_]
|||
123

1. FP ground in through 27ohm
2. output to 1C, non-banded diode to 12v source
3. 12v source



when I build it I use a 270ohm on the input (leftover from build) and two 1K resistors in series to jump 1. and 3. (leftover from build). This is what they use on the MSPNPs and this circuit is provided on the DIYPNP board and what I use for the fuel pump on 1.6L installs.

I've been building the following circuit for all NAs for quite a bit of time, it works rather well too:

http://users.forthnet.gr/ath/twikico..._schematic.png

http://users.forthnet.gr/ath/twikico...pump_board.png

Dimitris

Bah. :crx:
The circuit works; I used it to drive fuel pump relays on the 1.6 car. Nice catch Joe.

The DIYPNP v1.5 board has something similar onboard already.

I'm assuming you mean "Laymen's Terms". Either that or you are lamenting the function of the circuit. ;)

yeah that.

It could also be "Lamer's terms" or something.

dumb folk terms: