hello.

i have MS-1 pcb V3 with stand alone wiring.
and in its wiring is sticking out wire for VTEC_Out.

in this write-up is told:
Connect the VTEC_Out to your harness going to 1C.


this is my wiring:


where should i solder that brown wire (VTEC_Out) to? to 1C in my connector?
but there already is a fuel pump wire(blue one).

sorry for my pour english.

 

there is no vtec out.

Read the docs: vtec-out-from-ms would be the banded end of D4.

look at the diagram: vtech-out is lead #2 of the tip125.


Here:

 

The schematic is labeled as it is because it was drawn up as a VTEC control circuit. I just hijacked the same circuit to use with a 90-93 Miata fuel pump.

"VTEC OUT FROM MS" would be your fuel pump output trigger and "TO VTEC SOLENOID" would be the lead to 1C.

 

thanks for replies.

with VTEC_out to the wiring is done.

now, in my MS R16 is used for fuel pump. (i cant tell why, becouse I'm not the guy who assembled it)

so, to wich side of R16 I should solder the yellow wire?


to the left side of R16?

 

that's completely wrong. Look at the diagram I posted, that makes it too easy. You have the wires in the wrong spot and the diode is backwards.

Once you move the yellow wire to the correct lead on the transistor, you'll solder it to the banded end of D4, like the diagram says.


it also needs an insulator underneath it.

 

thank you for your help.

but this transistor ir tip 127, so everything is ok.
so I'v soldered yellow wire to D4 banded side and everything works

last night I'v tested my megasquirt, and my miata started with no problem, but it is working extreemly rich.
(my setup: Greddy turbo kit with 2.5"DP and 2.5" exhaust and stock injectors (ditched FMU). today I'm going to change injectors to Toyota Cellica 326cc.)

 

tip125, tip126, tip127 are one in the same.


do you have constant 12v on your green wire if the key is just turned to ON?

 

-

 

Assuming it is connected as indicated (eg: to the banded end of D4 or some other location on the FP-1 circuit), yes. The MS runs the fuel pump for a few seconds at power on, and then shuts it off if it senses that the engine is not running (RPM = 0).


Sidebar: TIP125, eh? Any particular reason you didn't go for something like an AQV252?

 

Cool IC, but it is several orders of magnitude higher in cost as compared to the TIP125 that we already keep on hand.