ok so i bought a gsr integra and put the b in my car and its been fine all day then i noticed that the vtec is not kicking in well i checked the cil and its the knock sen. from what i have been told that the knock sen detects a knock in the motor and puts the computer into a kinda protect mood. but heres the thing the motor sounds great and has no knock to it at all so can a knock sen. go bad? it not what else could it be?

 

and one more ? when you go from a d series to a b series do you have to rewire anything besides run the vtec wires i used the stock integra harness and there is an extra plug on the pass side it has two wires what are they for

 

yeah knock senors go bad. I dont know about hondas but i ve had a couple of chevys go bad and they retarded the fuck out of the timing

 

So, you swapped the motor? What is your setup?

 

Yea knock sensors do go bad. If its a gsr it should be under the intake mani in the rear of the motor. Under where it curls. I know you do have to wire vtec yes,but I THINK you also have to ground the knock sensor or use the gsr harness. If you just ground it you shouldn't get a cel.

 

If it's an engine swap, check the wiring. Most all of the sensor related problems that usually occur are caused by faulty wiring. Anytime I hear something like "it worked for a week" or "it worked in the car the engine came from" that sends a red flag...

 

Knock sensors are your friend. If you have provisions for mounting a knock sensor to the engine (like DOHC VTEC blocks) and an ECU with a knock sensor board in it, you'd be a fool to ground the input rather than using a functional knock sensor.