Anyone got a proper shop manual for this engine?

Somewhere in my poor memory I think the VTEC solenoid has a unique circuit configuration.

Most everything on Hondas have continuous battery voltage, and they are switched by the ECM on the ground side of the circuit.

The VTEC solenoid is unusual that it has only one wire. The ECM provedes 5v to turn it on; it is electrically grounded through it's mounting bolts. I think somewhere in the Helm book is a troubleshooting chart that gives that voltage, asking you to back-probe the plug or something. If someone can verify that it is indeed 5v, then the solenoid might not be good after all. Maybe it works at 12v but not at 5v.

 

You really need to get a hold of someone that can do some datalogging and see what's going on when you get above 4000 rpms. I really can't believe you're not throwing any engine codes. Have you tested for weak spark ?

 

Jim - That's an interesting theory. I have only read that the solenoid gets 12v though? If your idea is true, then that would explain everything.

holmes - I don't know what datalogging is lol, or who can do it. The spark plugs were installed new when the swap was done with NGK iridiums. Idk how to test for weak spark!

Roader - I started trying to test out the solenoid like you told me when I'm going down the road, but of course it started raining when I was wiring, so I stopped.

 

I assumed that the solenoid, being an actuator (vs. a sensor), would receive 12v from the ECU. I've never measured it. When doing my swap and stuck with a dead P0H I contemplated using an RPM switch to activate the solenoid. Didn't because the ECU changes the fuel mapping when VTEC is engaged and I just didn't want to risk it. There are people who use them, though, and run the solenoid with 12v.

Unfortunately the diagnostics in the FSM are all static: resistance checks of the solenoid and wiring. IDK about other manuals.

 

I can't find anything about testing the vtec solenoid in my mitchell on demand.

One more thing that this issue could be is maybe a clogged cat ? What was the reason for the swap ? Did you blow the head gasket on the old motor.

You could pick up a mittyvac and use the instructions on it to test for a clogged exhaust.

 

Got under the car today to change the oil, and to my surprise my oil pan was seeping oil all around! That would explain why my oil was so low. I called the shop and they said that's not under warranty (it should be). I wonder if that's why vtec isn't functioning...

 

Fill it to max dipstick line with oil and take it for a spin.

 

I've already tried that look back at my post on page 5. I had noticed that my oil was low so I filled it to max with no luck.

 

I literally just got the cat replaced. It was definitely clogged because my exhaust doesn't rattle anymore and I don't smell exhaust in the morning. Idk about the other parts if the exhaust. The shop that swapped my engine said I should try running it with open headers to see if it does the same thing.

 

That's what I would do. Just open it at the exhaust manifold to exhaust flange gasket. I'm guessing that's past the oxygen sensor which is what you want to do, open it up where it's past the oxygen sensor. It's going to be loud, just remember that.