this has happened before and it happened again. On my way home i was doing a slow acceleration up to like 95 on the freeway and the rpms were at the stock vtec
X-over but vtec was not on yet. (since i have a VAFC that rasied it to about 5200RPM). and the check engine light came on. last time i checked the code and it said it was a problem with the vtec system, but it still operates fine. my guess is that the computer is telling the motor to engage vtec but the vafc is hold it back until 5200rpm. since the computer does not see vtec engaging, it thinks that there is a problem. what do you guys/girls think?
by the way the car is a 96 gsr with Skunk2 mani, type R cams, vafc, and other bolt ons.
do any of you with raised X-over points have a prob like this.
can some of you try this in thier car and see if it happens to you, keep the rpms at the stock vtec point and see if it brings up a code. i believe you also have to be giving it a lot of gas to make vtec come on.

 

my guess is you didn't hook up the vtm wire to the vafc.

 

which ecu are you using?

 

no i didn't hook up the vtm wire. what is it for.
and how can i find out what ecu i have.

 

Yeap. VTM wire. If your CEL comes on while you're running the car, your car will be in "Limp" mode, which is bad.

Also, you should solder your wires onto your ECU. If you clamp it on, it can disconnect while you're driving and can cause some big problems to your motor.

 

well the car doesn't go into limp mode. it says it ok to drive and vtec still comes on. but its missing the vtm which i geuss tell the computer that vtec has come on. so when does the vafc send the signal through the vtm wire to the ecu? the instructions said that i didn't need to put the vtm wire on. but i guess i do. can someone tell me which pin the vtm wire is on the connector.