Hello, I have just swapped in a b16a into my brother's 90 civic hatchback, the car was dual point and was converted to multipoint injection before my brother got the car. So the harness was already messed with before we got the car, a resistor box was added and extra injector wiring. I swapped in the b16a and everything works and the engine runs perfect except one thing, vtec DOES NOT ENGAGE!?!? This is my first swap into a ef chasis, and this is my first obd0 swap. I believe that all of the wiring is correct because no cels are on. The car has a obd0 b16 sir ecu in it.

Things i have done or tried:
I have ran seperate solenoid, pressure switch and knock sensor wires straight to ecu.
I checked solenoid by putting 12 volts to signal and the solenoid clicks.
I swapped the original solenoid with another solenoid, thinking it may have been bad.
I checked the oil.
Car was at normal operating temp.
Tried another obd0 ecu.
Checked the timing
New spark plugs, wires
I hooked up a light to the vtec solenoid wire to see if the ecu was sending a signal to engage vtec, and it does at 4500rpm<but i feel no difference(since the ecu is sending a signal to engage vtec doesnt that mean all the wiring is correct??)

I am starting to run out of solutions as to why vtec is not working, any suggestions would be awesome, I am not used to obd0 and the ef chassis, if this is a normal problem or not.

Thanks for any suggestions

 

Im assuming that you have a obd0 pr3 or pw0 ecu..

You have the 2nd o2 sensor,knock sensor,vtec pressure switch,and vtec solenoid all hooked and pinned into the ecu clips in the correct location??

 

yes i have 2nd o2 also, i have checked over those 4 extra wires quadruple times. I am also using the right ecu. I really dont understand

 

Your speedometer works ?

Also you say the light comes on when vtec is supposed to engage,,But you dont feel a difference...Do you hear the vtec x-over at all? Because you'll hear it pretty loud..

 

The speedometer works perfectly. Everything works like normal except vtec. The car has a intake on it and when the light comes on NO difference is felt or hear, sometimes the car hits rev limiter at 7100 full throttle. vtec is not engaging it can't be, the car just does not feel right but no codes are thrown.

 

Maybe the oil pump is bad and cant give the oil pressure for vtec..Im trying to think...Have you noticed if the cel comes on in vtec..? Because 7000revs max isnt normal..

 

the only time the cel came on was when the car was under load on the interstate when i put it in 5th gear and floored it, the o2 sensor light came on, other than that no code.

The oil pressure has to be good, since the vtec oil pressure switch detected oil pressure so it sent a signal to engage vtec, right?

 

The part im confused on is the fact that the ecu is sending a signal to the solenoid. If the ecu is signaling a signal to the ecu, doesnt that mean all engine parameters are right to engage vtec.

 

Thats why I brought up the oil pump..My b16a engine is starting to do what yours is doing..Everything is 100% perfect running and wired up correctly..Solenoid clicks but it doesnt stay constant..At 5200rpm it engagaes but not fully,,almost like on/off/on/off while in vtec stage..And this is with only the solenoid wire hooked directly to the a/c clutch relay using turboedit to control it..I dont know what else it could be in my case besided oilpump..

 

did you ground the oil pressure switch to the Thermostat housing ( i think thats the one)

 

Yes it was grounded to the thermostat housing, I am goin to ground it directly to the frame. The only thing I have checked is the oil pressure, I will do that prolly this week, I am so stumped on this car. obd0

 

Hi. Try to swap wires from first o2 sensor to second... What is ur oil pressure?

 

I have not checked oil pressure yet, i am goin to do that tomorrow. Would swapping the o2 wires even cause a difference, really??? Thanks for some input

 

its not gunna kick in by itself if ur using a obd0 ur gunna have to run a switch from the vtec soleniod to a button and when u mash the buttin the vtec will kick in. If u dont want to do that then ur gunna have to make ur car obd1 then u would have to change ur computer and its wiring and ur distributer plugs. But just try to run wire from the vtec solenoid to power and to groung and when u mash the button u will hear the vtec kick in becuz i have a sohc vtec and im running 91 si, ecu,and distributer everything is obd0 and i just use the button it works find for me matter fact i took on a b16 Crx with my 94 sohc vtec so just try that.

 

I have a obd0 jdm b16 ecu not a usdm ecu, the sir ecu should engage vtec as it did factory like it was supposed to. I hooked up a light also, and it shows that the ecu is sending a signal to the solenoid to engage vtec.

 

checking pressure today