You should check for oil pressure. Do you have any dents on your oil pan? It needs sufficient oil pressure to activate vtec or it won't kick in.

 

Last time I changed the oil I didn't notice any dents. My oil change is up again so I'll look around this time.

 

Your P0H-L51 ECU shouldn't have an input for a VTEC oil pressure switch line. I don't think any '96 - '97s have pressure switches. The '96 - '97 ECU harness has an empty slot where the oil pressure switch line would be on a '94 - '95 harness:



The engine may well have a VTEC oil pressure switch; my USDM F23 does. It's just not hooked up. The P0H ECU doesn't know to look for it.

 

So you're saying the F23 doesn't need an oil pressure switch for VTEC to function? If so, then they added it on for no reason. It didn't come with the switch they just added it on there and wired it to the ECU. They haven't even tested my VTEC solenoid to see if it's functioning.

 

Roader, where does your F23A redline?

 

Correct. But my F23 hasan oil pressure switch, it just isn't wired up. For some reason Honda decided to not use VTEC oil pressure switches in '96 - '97. '94 - '95 have them, as do F23s from 6th Gen cars (at least my year 2000 engine does; IDK about other year 6th Gen's.) I'm talking USDM. I also don't know about JDM engines although it's easy enough to look to see if has a VTEC oil pressure switch.

But it doesn't matter. Your P0H ECU can't deal with a VTEC oil pressure switch. That's OK. The VTEC solenoid should work just fine without the oil pressure switch wired and working. Mine does.

IDK what the official redline is. I ran my F23 swap with a P0J ECU for a few days because the P0H I bought was junk. Without VTEC kicking in the car ran great below 2500 RPM - better than the F22B2 it replaced - but was a dog from ~3500 RPM up. It just ran out of breath. I don't even know if it would hit much more than 5000 RPM with the gas to the floor. After I put the P0H ECU in it pulls hard in the upper RPM range and easily spins to 6500.

It should be pretty easy to figure out if your VTEC solenoid is wired. There should be a wire running from pin A8 on the ECU to the solenoid. That's it, nothing else.

 

I checked the wiring and they definitely have the solenoid and pressure switch wired to the correct pin outs. This leaves me to believe that the solenoid may not be functioning. I'm gonna ask them to test it and see but isn't there a filter on the solenoid? Or is that on the pressure switch?

 

I just realized you're using the ecu for the original car versus the engine. You should always use the ecu for the engine you're using. I think the fuel trims are going to be different. That could be your problem and you could be running lean. Just a thought.

 

I'm using the P0H ecu from the 96-97 accord EX. My original is the P0J. I tried using the japan ecu that came with the engine but it won't even start because that one is OBD2b.

 

When I swapped the F23 into my CB7 I used a chipped P28 with a custom map for an F23 on it. I had to wire VTEC to the ECU because the harness I used didn't have it, but everything ran and worked great. I'd consider getting a chipped ECU and converting to OBD1.