Hey guys got a lsv in my ej8 with a chipped p72. Well long story short rod knock, rebuilt, babied it for 500mi, gets vtec back and it seems perfect...
than once my car warms up to temp and my car doesnt hit vtec and can barely reach 6k rpms. Im stumped. When my cars cold it runs like a champ
not mentioning im not tuned but when my ecu is in my friends GSR it hits vtec no problem, if his car is cold or not. Which drew me to the conclusion
it has to by my car. A sensor or something that only effects my car when its warm. Any feed back or ideas please

 

You could test the coolant temp sensor. But I doubt its that. For one thing, check that there is correct fuel pressure. If fuel pressure is good go to the dyno. Stop trying to compare your problem to other cars and different setups

 

Going to check all this today and also try a different vtec solenoid cause I was reading about a prelude with the same problem and that fixed it.