I installed apexi vafc vtec in my teg to run the vtec off the ls ecu. My problem is that when the vtec engage it doesn't seem to be pulling it seems to stumble and also seem to like shut off. What could cause this? The car will still go to redline but it does it slowly. When i use the monitor setting on the vtec controller for the ecu vtec output the reading on the apexi keeps switching from on to off. Anyone that has this does your do that when you stepp on the gas pedal? it only switch from on to off when i step on the gas and when its idling its reads on constantly. If the vtec soleniod doesn't get 12volts or gets too much does it also affect the engagement?

 

did you make sure that your non-vtec oil pump is enough to keep the vtec system engaged? That may be why it's jumping on and off. You may also need to tweek your fuel curve as well.

And yes, voltage will affect the solenoid. Too little, it may not engage fully, or may sort of *hop* between engaged and disengaged. Too much voltage, you'll overheat the solenoid, possibly damaging it.

 

im not sure if the oil pump is a gsr or ls cause i had the motor rebiult and they said they would put gsr parts in . Is it also because im running the ls ecu?

 

The LS ECU doesn't have VTEC fuel maps, which are a LOT more agressive after VTEC switches over since the engine is ingesting more air with the higher lift, it needs more fuel. Unfortunately, this will be a trial and error thing for you unless you get some dyno time to sort it out.