So lets hope I get all of the important info covered in the first post lol.

I picked up a 94 LS with b18c5 swap in it about a month ago. For the first week vtec would hit just fine at 5900. Since the first week, it will no longer engage. Its a b18c5 motor. It has an apexi vafc 1 controller attached to it. I tried downloading a manual for it but because its so damn old I cant seem to find one lol. I've never had one before so I don't know how to adjust it. The oil level on the car is fine. I have an intermittent CEL that I cant check because if I turn the car on and its suddenly on, the very next time I turn the car on its gone....

The only things Ive done since owning it (not saying this are the problem, just listing all that I've done so far) was oil change, spark plugs, dizzy cap and pulled the broken A/C system.

Also, here is a picture of my temp guage after full warmed up and driving around town for 30 mins, doesnt this seem a bit cold? Could that be effecting the engagement? Im thinking maybe the thermostat is stuck open?

 

Your temp gauge is normal. That's how majority sits.

Also, check your VTEC solenoid. That might prevent your VTEC to engage.

 

why do you even have a vafc on it?

 

VTEC needs:
-oil pressure
-rpm signal
-throttle signal above 10%? Something like that
-vss signal above 12mph
-coolant temp signal.... warmed up
-vtec hardware and software functional

The VAFC bypasses all that. VTEC will always operate at a set RPM...unless there is a bad connection or setting in the controller.

Check the wiring to the solenoid under the hood. Check the wiring to the VAFC and ECU under the dash. Then remove the controller and fix the wiring back to stock if it doesn't work. Follow the VTEC trouble shooting guide in the manual...or look for it online.

The VTEC solenoid screen could be plugged...but in most cases, the car will rev limit to the VTEC RPM if it gets clogged. Check it just incase.

What ECU is in the car? Why is there a VAFC? To lower the VTEC point because the wrong trans is in the car?

 

hopefully you would have been able to gather from my OP that I did not put it on, it came that way.... I already acknowledge I dont know anything about it or how to use it. To my understanding its wired into the ECU so I havent removed it..

I'm not positive on the ECU on the car, I believe its just the factory P73 but I can check after work. Previous owner said the vtec engagement point was adjust with the VAFC, so I assume thats why he had it. It has skunk2 cams, b16 tranny. Wiring to the ECU and VAFC will be spliced coming off of the solenoid itself?

 

The coolant temp signal is why I was asking if the gauge looked like it was reading low temp or not.

 

It looks about normal. Even if the thermostat was stuck open, at the point of the picture, it's warm enough to engage VTEC.

the VAFC wiring is from ECU harness under the dash to VAFC. However, the wires under the hood do have to lead to the right places too, for the signal to get to/from the sensor.

Check the solenoid screen. If it's clogged, thats an easy fix. Clean it with something that wont destroy rubber. So...not brake cleaner.

 

I appreciate the help. Ive had a few honda/integras before but this is my first vtec motor. So I don't need to remove the valve cover to get the solenoid off right? And is there a gasket that will need replaced when I pull it? I havent messed with any of the wiring (though it is shotty as ****) so I dont know how it woulda just gone out out of nowhere. I didnt notice it right away because I dont normally drive my car hard enough to hit vtec lol.

 

No problem. The solenoid can be removed by taking off 3 10mm bolts that attach it to the head. No need to remove the valve cover. Once you remove it, you'll see the screen. It's attached to the gasket. If it's real old or dirty or oil is leaking out of the gasket onto the head...replace the gasket amd screen. Use genuine Honda parts. It's like $20 on ebay.

Good luck bud.

 

Thanks for all the help BSerious. Ill update with what happens

 

No probs. I would maybe remove that VAFC for simplicity. Maybe wiring was not previous homeboy's forté. I've seen cars with entire harnesses twist tied and taped together. When these "bulletproof" connections came apart, mystery problems would aarise.

I always solder harnesses that I build or repair.