Nicolas L

Hey there.
I've been trying to get my IDLE to work, but I get no reaction at the solenoid no matter what I do.
I know the Idle valve works because my stock ECU sucks at controlling it and it affects the idle, so the problem has to be on this side.

I'm based on this circuit:






I have continuity between B and top of R19 (0 ohms)
I have continuity between E and ground (0 ohms).

I have nothing between C and anything else inside the board, it only conducts to the pin in the DB37.
I'm ignorant about this kind of devices, is it supposed to be like this until it gets some load on the collector? How can I test that this TIP is not dead as it seems to be?

Thanks!

EDIT:

I just refreshed my memory a bit on the basics of transistors.
So basically as long as I get some current from the CPU thru R19 on the base I should get the collector grounded because there is flow between C-E right?
I have a 4.9V difference between the B side of R19 and 5V. Is this normal or my R19 has opened the circuit?

Nicolas L

Ok I have continuity between Base and Emitter forward and backwards. Shouldn't this be open one way at least? I get 0 ohms

Nicolas L

I've changed the TIP120 for a new 122 and I don't think the behavior has changed :/

Nicolas L

Anyone? Is the last thing I need to get this **** running normally. I have compensated the idle with closed loop advance but it's not really the best. It idles pretty good and stable, but I don't feel it confident.

The last thing I did was remove the CPU, send 5V to pin34 of the CPU, connected an LED one side to the PIN30 of the DB37 (FIDLE), the other side to a 330R that then goes to 5V. No matter what I do I still get nothing.
I changed the cables out of the Q4 location and directly over right side of D8 for the out and the right side of R39 to ensure they weren't touching in the cramped location of Q4 and I STILL GET NOTHING.
It's driving me crazy, I hope someone here knows where else this circuit might be touching at.

The 5v hit at R19 and from then I get confused.

EDIT:

HOLD ON, I think It's going to work. I got the damn collector to ground when I put 5V to pin 34! So tomorrow I'm expecting this **** to start playing with the PWM solenoid! Before it was always an open circuit at PIN30 of the DB37. Exciting!