So recently I have not been able to hit vtec or any rpm over 6k. Now what I mean by this is 1k-5.5k the car acts and drives like it should but anything over that it breaks up like there is a fuel related issue. Now this only happens in vtec. I would like to think its just the vtec solenoid since thats where the problem starts. There are only bolt-ons on the car. 168k in miles

 

I am having the exact same issue. When did this start? Any mishaps you can think of? Mine is currently at the shop. Mechanical and all electrical have checked out.as well as oil pressure. Still chasing down any issues.

 

Fuel injectors?

 

Hate to be alarmist but mine was oil pressure related. Low oil pressure meant no vtec engaging and then the a/f goes super rich and bogs down

 

Chances of the VTEC valve malfunctioning are extremely slim.

 

Its been happening for the past couple of weeks i drive the car but i stay a away from vtech and everything is fine. I can rev the car to 9k and everything is as it should. tomorrow im going to do a little teardown to see if i can see anything out of order and check my vtec solenoid.

 

I do not believe it is the fuel injectors because it would have been doing the same thing if i were to redline while not under a load

 

So we have the exact same issue. Check vtec solenoid screen. The shop has checked oil pressure in three locations and all is good. It free revs to 9k as well just won’t go past 6k underload.

 

have you checked yours? If so what were your findings

 

my gaskets are both new top and side. Not my issue. So far everything is checking out. Have you checked to see if your ecu is firm and in place? I have heard they can ground out not sure how true it is but also not my issue.