Hondata

Hi all,

I have search the forum and nobody seems to have this problem.

03 Type S supercharged
Intake
Exhaust
3.0 inch pulley JRSC kit with 520CC injector

The car was on a dyno and after 6 runs fine then the knock sensor malfunction shows up and check engine is on. After that the Vtec won't kick into high cam.

question to those who knows, if knock sensor is defective, can it affect Vtec operation?

Maybe a stupid question? Did you check your oil??

The oil was full and I even change the oil after it stopped working.

520cc injectors are far to small for a 3.0" pulley. Your knock sensor could have gone crazy because the engine was tearing itself apart with detonation. It could also just be a loose bolt making noise. What was your a/f and knock count during these pulls?

Wayne

Kpro AF ratio was 11.47 to 11.51. I have richen it until power started to drop.

This was on the dyno and there were only 1 knock count. Duty cycle was around 84% at 8300rpm. AF ratio after 8000rpm is around 11.5

I have checked the plugs afterwards and its fine. There were 3 people in the shop and we were keeping a keen ear on knock and heard nothing. Engine pulled really strong.

I think there was spike in either voltage or current and that blew the knock sensor. I know this because one of my amp was blown without it even being on. The weird thing is that Kpro tells me everythig is OK except for knock sensor. It even switches to high cam but I know its not cause right after VTEC crossover, power drops like mad compare to previous pull.

crackerjack wrote:Kpro AF ratio was 11.47 to 11.51. I have richen it until power started to drop.

This was on the dyno and there were only 1 knock count. Duty cycle was around 84% at 8300rpm. AF ratio after 8000rpm is around 11.5

I have checked the plugs afterwards and its fine. There were 3 people in the shop and we were keeping a keen ear on knock and heard nothing. Engine pulled really strong.

I think there was spike in either voltage or current and that blew the knock sensor. I know this because one of my amp was blown without it even being on. The weird thing is that Kpro tells me everythig is OK except for knock sensor. It even switches to high cam but I know its not cause right after VTEC crossover, power drops like mad compare to previous pull.

You should upload a datalog if you have one.

Here is a datalog, this was done on a 30C day with low humidity at 3500 feet above sea level.

this datalog was done on a mustang dyno 4th gear.

Well, the datalog you uploaded seems to show the knock sensor working perfectly. I don't have anything to contribute to the actual problem you were asking about, but I did notice your cam cmd is 49 while your cam can't seem to get past 45. Additionally, a 3.0" pulley on an 02-04 type-s crank pulley and a k20a2 motor should be making 11 pounds, not 9 -- assuming it can hold tension, which is next to impossible to begin with. That is why I said 520s should be far too small.

Does this car have a stock motor? Perhaps an underdrive crank pulley?

I just saw the part about 3500 feet above sea level. Wow. I think that explains the low boost and ability to run 520s. I would be aware that if you go to sea level, your car will not run well with those 520s at all.

update

replaced the knock sensor, erase ECU and then upload the same cal with knock turned on. Kpro now tells me everything is good and no error to report. Under boost the car still won't go into VTEC while Kpro says high cam.

car drives like normal. Can't explain it.

RAZ, I am getting larger injectors because the kit comes with 550RC and they were not good at partial throttle. I am looking into HKS injectors which i know works really good.