knock retarded

[drift-it]

hi guys,

i've been helping a mate with his vs senator. its been lacking a bit of power and code 43?? knock sensor fault is always thrown. after some logging i noticed that it was pulling 12 degrees timing whenever the accelerator was touched. i got him to replace the knock sensor. now it always pulls 6 degrees and throws the MIL.
we replaced the knock wire as it was rather stuffed. and we also swapped ecu/memcals to rule that out.

so im either thinking its a faulty knock sensor? is there anything else that i've missed or could try? he doesnt want knock disabled. he has a chiptorque chip with knock board removed and obviously that doesn't throw a light?

cheers,
zac

[Holden202T]

the chiptorque chip will probably not throw a light cause its probably disabled in the tune due to no knock filter on the memcal.

[yoda69]

Is it a genuine V8 knock board on the memcal?
What is the code on the knock board itself?
If its a V6 one like the guys on eBay are selling as V8 ones you will have problems.

Yoda69

[drift-it]

yer the chiptorque chip does have knock disabled.

the knock board number is 1F9216. its not a chip from ebay so it should be ok.

[yoda69]

The only other times I've had problems is with noisy engine(lifters it valve gear) or where exhaust has interference to the body(k-frame or underbody).

yoda69

[Holden202T]

yeah i think 1F is V8 so it should be fine.

there must be something else causing it.

is the motor rattly at all ? like lifters or timing chain etc ?

[drift-it]

he had roller rockers fitted last week. however i have multiple logs before the rockers showing the same problem. i havent had much to do with v8's so cant comment on how noisey it is. the engine fan was totally shagged the first time i looked at it, like turn it and it makes crunchy noises shagged which has been replaced, the exhaust has a leak at the cat thats getting fixed.

is there anyway i can turn the sensitivity down of the sensor?

[VL400]

The 12 degree and 6 degree are significant. On a standard cal 6 degree is pulled for a code 43 while 12 degree is the most a working system can retard. If there is a constant 12 deg how many counts are you seeing? No, or a faulty, filter will show around 200 counts all the time and pull Max 12 deg.

Now with 6 degree there is a voltage on the knock sensor wire that is not in spec. If you used a vs v6 or later sensor it will throw the code unless a cal change is made. Should have 4k resistance between ground and the sensor wire when no ecu is plugged in.

[drift-it]

ok, ill bring the multi meter home from work and go have test resistance. cheers guys. will let you know the outcome next week.