My car developed a sudden loss of power up top, initially I thought it was an ignition problem bc it’s breaking up top. Feels like I hit a wall around 6k rpm. Turbo, motor, all looks and sounds good, idles fine, no other issue except what I mentioned. I emailed Evans and he suggested to inspect the vtec solenoid because the log I sent him shows none of the protection features kicking in




“There is no protection feature kicking in at all. Based on what I am seeing it looks like VTEC is not functioning. AEM won’t give a diagnostic status like the OEM ecu if its actually functioning or not. It just turns the solenoid on, and runs the same fuel and spark as with VTEC engaging. The boost control is way undershooting from target, and the AFR is very rich. Both indicate that its not switching to the high cam. This is most likely due to oil pressure. I would pull off the VTEC screen and check if its clogged up”




So I pulled the solenoid, inspected the filter and it was impressively clean. I did see something off with the plunger, not sure if it’s supposed to look like that or not but it looks somewhat open. Fuel pressure seems consistent and healthy.




I really hope it’s something simple man, I’ve had a string of bad luck with this car and it will suck for it to be valvetrain related. I have supertech valves, springs & retainers. I’ll pull the vc tomorrow, I’ll be praying in the meantime.




Pics and vtec settings on aem v2 attached

 

If you can see your oil pressure, it should drop 10-15psi when vtec is engaged. At least then you would know it is most likely working mechanically.


I have had a similar issue when I was down on oil maybe 1.5 quarts (had a slow drip leak from the oil drain bolt). I noticed it happened only going uphill, and took me a while to think about the oil pickup not being able to pickup oil.

 

Oil level is at the full mark,
some have suggested to test the solenoid but

tbh I’m not too electrically savvy. All I know is the connectors are gone. There is a bolt used to plug the vtec oil pressure sensor since aem is controlling vtec. There is only one wire runing from the vtec solenoid cap and merges to the coil pack loom

 

You would just have to ground the body of the vtec assembly and apply 12v to the single wire that goes underneath the cap of the solenoid.

You should be able to hear it click. It still doesn't mean the valve works 100%, but you would at least know the electric side isn't dead.

If it were me, i would unplug the connector at the ecu and test (apply 12v) to the vtec wire from there.


Also i have a sidewinder manifold and have cooked the vtec wire before. The wire didn't burn, but it did harden and become brittle. The copper stands eventually cracked inside the cover of the wire.