Hi Pfc Knock Could The Sensor Be Faulty?

[grepin]

Hi all.

Wondering if anyone is getting rediculously high knock indications.

Pretty sure it started happening once the solid lifters went in the head however am getting high knock indications when just driving around at 60kmh. Reads 45 to 60 knock. At around 6000 rpm it will knock briefly (light) then it dissapears. Doesnt really happen on the dyno however.

Happy the tune is fine and not audible to the ear even with a headset/tube on the motor.

Is it possible the knock detector is faulty?

Any similar experiences.

[paulr33]

use temp IGN adjust, take out -4 degrees and try and repliace it

see if you get the same knocking at 60km/h

it sounds like a few spots have too much advanced ignition timing

which can be easily fixed.

but knock sensor can pick up other nosies, bumps, rattles, road noises etc.

they just listen for a set freqency

[Chris32]

I am of the opinion the FC-Logit software has made my knock sensors read faulty. I don't know how/why, but ever since I plugged it in, not changed a thing with the tune, it gets random knock

Not detonation, as on the dyno we took timing from 16* to 10*, lost power but still the same knock levels

Has anyone else with FC-Logit experienced this?

[Duncan]

also make sure the knock sensors are botled to the block securely as well

[grepin]

I am of the opinion the FC-Logit software has made my knock sensors read faulty. I don't know how/why, but ever since I plugged it in, not changed a thing with the tune, it gets random knock

Not detonation, as on the dyno we took timing from 16* to 10*, lost power but still the same knock levels

Has anyone else with FC-Logit experienced this?

Never used to until the new head went on. But not sure if that was the exact time.

[Chris32]

I think Cubes and Bl4ck32 are also having similar issues since using FC-Logit, I reckon its something to do with that, as mine does not knock

Could be the soild lifters in yours mate, have heard they can sometimes need re-shimming on GTRs?

[paulr33]

you could ask on the datalogit forums?

are you all (who are seeting the same problem) using the same PFC version ?

[Cubes]

I think Cubes and Bl4ck32 are also having similar issues since using FC-Logit, I reckon its something to do with that, as mine does not knock

hrmm very interesting...

I am having a det issue around 4000-4500rpm but I am getting a little valve float so I've put down to this for now.

I've dropped ign. levels to stupidly low and richened afr's with only a slight improvement.

Bl4ck32, when I had the logit hooked up and was watching there was a spot around the same rpm as mine that required a heap of ign. to be pulled out.

Peak torque was seeing around 18degree's where as this silly spot higher in the rpm being only 1 or 2 cells saw little difference to knock levels if I pulled out 10degree's. I didn't fiddle with fuel, but now I am beginning to suspect it is indeed fuel.

Either way 18degree's at that point was stupidly high seeing 100+ knock. I dropped it down to around 15 which only see's knock of 60 odd at that rpm.

BUT.. Bl4ck32 does have coil issues so this issue only showed when the coils were cold as once they were warm there was no chance in hell of hitting that load point due to massive missing.

There's too many variables for bl4ck32 and my own case, I'm dropping springs in as soon as exams are over so I'm crossing my fingers there's no det.

Apart from that my knock sensors read rather reliable, cold start see's around 10 and if I run too much ign. at cruise when cold knock levels will sit on 30 odd.

I'm guessing this is due to the cold start fuel + adv. ign. causing slight det at light load.

Bl4ck32's initial tune didn't have the logit hooked up and saw no det issues, my initial tune did have the fclogit hooked up and had no det issues.

Later down the track I began seeing issues with det AND lifter pump up so this is where I have put the two together and decided my det issues are caused from lifter pump up. If I lower boost I get no det and no lifter pump up.

Providing its not puffing black fuel out on the dyno and you can't hear anything its not detonating, as you stated. Its still worrying though.