Jump to content
SAU Community

Hi Pfc Knock Could The Sensor Be Faulty?

grepin

By grepin,
in Engines & Forced Induction

 Share

Recommended Posts

grepin Experienced

grepin

Posted
Posted

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 Grand Master

paulr33

Posted
Posted

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 Veteran

Chris32

Posted
Posted

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?

grepin Experienced

grepin

Posted
  • Author
Posted
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 Veteran

Chris32

Posted
Posted

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?

Cubes Grand Master

Cubes

Posted
Posted
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.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Dose Pipe Sutututu
      NC MX5

      By Dose Pipe Sutututu · Posted

      The German place in Cabramatta was rock solid, fresh pretzel cooked to order back then. Then it went all quiet, after all the poker machines were removed, then I believe it closed for good. I did drive past the other week and noticed outdoor lighting a big screen, but no idea what is there now.  
    • joshuaho96
      R33 GTR running -9 with no tune

      By joshuaho96 · Posted

      Yeah I suspect even if you hold airmass per cycle/cylinder constant if you get too far away from stock you're still going to have problems running the factory tune within the bounds of the factory load scale. Cams, different displacement/rod ratio, etc. I'm just lucky that the GTIII-SS with wastegate boost + CA compliance cats is pretty much equivalent to stock turbos. When I have actual space I can finally get it tuned and modify the fuel system for flex fuel to 100% handle any detonation concerns when cranking the boost to whatever those dinky turbos can put out.
    • The Bogan
      NC MX5

      By The Bogan · Posted

      I would say no, why, because my daughter, who also lives in Goulburn, hasn't recommended us going there Pity, as we miss all the German joints around in Sydney, actually, the restaurants are the only thing I really miss about Sydney, and a special mention to Ishibanboshi at Bondi Junction, their Kara-age Don is heart cloggingly deliciousness (always added a special boiled egg...or 2) 😋 
    • GTSBoy
      NC MX5

      By GTSBoy · Posted

      Does that German restaurant still exist in the old place out the NW end of Goulburn? When I say "out the NW end of"...I am really being vague. It was 1997 when I was last there, and the only point of reference I can recall is that it was on the opposite side of the main drag from the big merino. And when I say "opposite side of the main drag", I don't mean "on the main drag". It was either a couple of streets back from there, or might have even been out in the sticks a bit further. Was an old farm building or mill or somesuch. And when I say "the big merino" I might actually be thinking of a completely different part of town, because I just looked on maps and the big bugger is not where I remembered him to be! The food was good, consisting largely of various German mystery-meat sausage/loaf things and kartofflen.
    • GTSBoy
      R33 GTR running -9 with no tune

      By GTSBoy · Posted

      So while the second sentence is completely correct and the whole point of the conversation, the first sentence bears consideration. If this bloke is just hoping to throw big turbos on and drive it around, because there are no helpful facilities at all in his tropical paradise** then he likely has zero chance of even knowing what the TP is on the last column in the stock maps, let alone know whether the ECU is operating anywhere near it or past it. So the point is very very moot. And, per what I said before, at stock boost on those turbos, you may well be off the end of the map. **I'm just back from Vanuatu, so I know exactly what small Pacific nations can be like wrt paradise without requisite facilities. But it's not even that simple. I put a high flow on my car and had to drive it around without a proper tune because of the lack of opportunity*** to put the bigger AFM and injectors into it to allow it to be tuned. I had to turn the boost down to less than I had before, and back off the boost controller's ramp, because it was exploring parts of the map that it didn't drive in before, and really couldn't access for tuning on the dyno either, and so was pinging. It was still well within the last column, because when I first**** set up the Nistune on the Neo I rescaled all axes of the maps to give some more space to explore. ***Family dyno was broken ****This was 13 years ago, and the TIM thing wasn't a thing then and so TP would definitely grow when pushing past the stock tune's limits.
×
×
  • Create New...