I figured the easiest way to explain would be to show you what I did. I made a separate harness for VTEC and the knock sensor and ran it through the main hole in the firewall (rather than by the A/C lines).
One wire from VTEC solenoid to ECU.
One + signal from oil pressure switch to ECU.
One - signal from oil pressure switch to chassis ground (or other appropriate ground).
One wire from knock sensor to ECU.
That’s all you need and everything should work fine.
i’m using a p72 computer and in the ecu pinouts it says that i have to add a wire for the purge solenoid valve it goes in a20.
so far i have the following :
One wire from VTEC solenoid to ECU.
One + signal from oil pressure switch to ECU.
One - signal from oil pressure switch to chassis ground (or other appropriate ground).
One wire from knock sensor to ECU.
Yes, I realize the motor is a 2nd gen B16, which means it’s an OBD1 or 2 motor going into an OBD1 car.
The purge control from pin A20 is not needed for VTEC to function properly. Just the items I listed are necessary.
Part of your problem lies in the fact that you’re using the wrong ECU. A P72 is for a USDM B18C1 or JDM B18C, which uses the upside-down style intake manifold with two sets of butterflies. That ECU has another pin-out to control the secondary butterflies (which is pin A17 on the P72 ECU).
For starters, why don’t you tell us what codes your car is throwing?
vtec is not engaging . i tried a p13 and its the same thing.
i bought the engine for the price of a 1st gen because the
supplier i buy from is on vacation so the guy replacing him does’nt know anything , so i asked hi for a compete 1st gen swap , he asked me to find the one i want and put my name on it. so i picked a 2ng b16 with ys1 tranny . along with the swap he sent me the non obd pr3. if i go back to him and say this is the wrong ecu thenhe will realize his mistake.
the non obd pr3 is useless for this car so i tried the p72 vtec not engagin throwing code 6. tried p13 and same thing. i have a freind www.hyperducktuning.com he said he can chip a p28 to the b16 specs and it should work.