Ls/vtec vtec wiring?

Hey i have searched endlessly for this topic. I have an ls/vtec teg. I am having troubles with vtec. I have wired it many different ways and at the moment i ahve it working. My question is what is the correct way to have vtec for my setup. I know if I had a pr3 or any obd0 ecu i could plug right into the pins but i am running the pr4 ecu with the vafc. I have the vafc installed as correct as i can go for now. I am having troubles to what wires on the vtec solenoid should go where. The green connecter i have one prong with battery power, while the other prong is wired to a ground. the wire with continuous power is also ran into the cabin. The third wire i have is connected directly to the vtec solenoid. on the whitish looking plug. I have found if you touch these two wires i have now together they produce the solenoid to open creating vtec. I am wondering if this setup i have is correct, or if i should have less wires or the wires installed differently.

First you need to get the V-AFC Instruction Manual. Check out pages 11 and 16. Page 16 shows you the pin-outs for the ECU. Pin-out diagram H1-a is the diagram for our cars. Page 11 shows you where each wire from the V-AFC connects to. You don’t need to connect the VTM Signal wires. Don’t wire up the vtec solenoid the way the directions tell you. To wire it up using a PR4 ECU, you just extend the pink wire (Vtec solenoid signal output) from the V-AFC and directly connect it to the solenoid. You don’t connect the purple wire (Vtec solenoid signal input) to anything. Good luck and let me know if you got anymore Q’s. Later. :cool:

I extended the pink wire to the solenoid but where would i plug it in… the whitish connector that has one pin… or the green connector with the 2 pins? and if i extend just the one wire, what do i wire to the other 2 pins that are not used then? I know i shouldnt be having this much trouble but I had it wired another way which i had vtec but now i get vtec once when i start the car and then it stopps working then i have to turn the car completely off and restart it again to have vtec. I am also having problems with the pressure signal and throttle signal.
The pressure signal i cut the pressure wire on the pinout, and wire it how the directions on pg. 16 tell me then the engine acts liek it wants to die and triggers the mass air flow sensor. So it runs really rough at idle and does not even give me a pressure reading. Also i have the throttle wired correctly to my knowlege and that also doesnt read correctly? it either tells me 0 or 100%. I have done the self learning procedure also. I have wired the vafc into my friends car without any troubles, i just am having major difficulties with my application.
Thanks, any input would be appreciated.


The pink wire gets connected to the whitish connector that has one pin. The green connector with 2 pins isn’t used. So nothing is wired to it. For the pressure signal wire, are you sure it’s wired correctly? When you cut the p.s. wire the end that goes to the motor is connected to the white wire coming from the V-AFC. The other end of the p.s. wire that’s going to the ECU, is connected to the yellow wire coming from the V-AFC. Maybe you have them reversed or you don’t have a good connection. Your throttle display problem could be caused because, you either didn’t do the self learning correctly, you don’t have the throttle sensor type setting arrow pointing at 2 o’clock, or you need to press the < arrow > buttons on the V-AFC till it displays correctly. The V-AFC has a memory replay option where it will freeze what was displayed. Keep pressing those arrow buttons until the throttle display says 0%. I know this is all confusing but you’ll get it. Good luck.