H22a swap from japan and vtec isn't working all the time. no codes, was already at honda and checked out and they said it was working but you can deffinately tell when and when it isn't working. it's also in a 5g civic so im sorry if this is in the wrong section. anyone have any suggestions. thanks in advance.

 

do you have enough oil?

 

yupyup

check ur oil level and check for clogged or cracked fuel injectors, or fuel supply problems.

~boom

 

maybe the motor is too cold. my h22a has got to be really warm for the vtec too kick in. it only works under certain conditions.

 

check oil level and make sure the engine is warmed up before you try to hit vtec, you can blow your head gasket that way.

 

This might be stupid but sometimes if your coolant level gets low enough then the coolant temp sensor wont read as hot as it actually is and that would cause you computer to think youre not warmed up.

Its simple enough just to check

 

What ecu are you using? If you're using a moo-gen type race chip, they typically disable a lot of things that would otherwise throw a code. In that case you could just have a bad connection. If you disconnect the VTEC or VTP wires do you get a code? Might also disassemble the VTEC solenoid and clean/inspect it. Make sure that coil has the right resistance.