Knock Sensor At 109 On Power Fc

[hesh12445]

Hey guys got my car back 96 gtr from tuners its got the following

Hks 264cams

Hksadjustable gears

Port poished head

Tripple core radiator

Hks headgasket

Power fc

16psi

Gtr 34 turbos

N1 oil pump

Nismo thermostat

The tuner said the car is fine makes healthy 273kws at 17psi with knock on ppwer fc only reaching 29

I thrashed it for couple of dayas and was fine but tonight i belted it and the fuel was really low on the indictor near E but still had fuel

Now the knock sensor jumped to 109 on full boost in 3rd and temp also got to 87 when it usuLly stays at 73 . Turned of car and turned on and drove around then thrashed it and again 109 knock but the car sounds fine and now i know the power fc detects smallest knock or vibration and my car does vibrate alot could it be motor or the ecu fault? Or maybe low on fuel? Explanations

[Ben C34]

Yep.

Could be due to low on fuel.

Or tune issue.

Or failing fuel pump.

Or dodgy old knock sensors playing up.

Etc

The obvious and easiest thing would be add fuel fuel and see what happens.

Of it does it again go go back to tuner and put on dyno to check check for knock to rule it out.

Edited June 16, 2014 by Ben C34

[hesh12445]

Thanks mate the fuel pump is brand new tuner installed. It was never knocking on dyno and it mever knocked for days was sittjng on 29 until petrol droped below a quarter? Im just scared it my motor cuz i blew one up prior lol

[Humbla]

Fill it up,never drive my non gtr below quarter of a tank ever.still going good after ten years .

My tuner told me this. :-)

[rondofj]

109? I reach 150 and sometimes higher after a hard flogging for say 10-15mins, back off straight away when this happens and let it cool down - tune has been massaged to goodness by Unigroup but is still not ideal for circuit work because I think timing could be high. Intercooler is fine - exit pipe is cool but crossover pipe over engine gets too hot to touch, so reckon its the heat. Pump, injectors all good. Only does it in 3rd gear and up at 6000+ rpms.

Edited June 17, 2014 by rondofj

[GTSBoy]

You should consider a little water spray Ron.

[Blackkers]

109? I reach 150 and sometimes higher after a hard flogging for say 10-15mins, back off straight away when this happens and let it cool down - tune has been massaged to goodness by Unigroup but is still not ideal for circuit work because I think timing could be high. Intercooler is fine - exit pipe is cool but crossover pipe over engine gets too hot to touch, so reckon its the heat. Pump, injectors all good. Only does it in 3rd gear and up at 6000+ rpms.

You could insulate the intake piping to see if that makes a difference.

In theory it should but on full boost/decent RPM the air in your intake moves so f**king quickly that it doesn't have time to sit around absorbing heat

[rondofj]

Yeh, thats what the theory is - that it moves too fast to get hot - reality is its too hot to touch after a long and decent flogging, and its not my intercooler cos the cooler-out pipe is always at outside air temp to the touch. And yes got exhaust wrap around my piping over engine bay where I could wrap it - makes huge difference to previous without. Very good mod, this.

And water spray was my previous consideration but seems this isn't really popular - was intending to go down the route Mafia did with his 33..

[hesh12445]

Yeh its bugged my only theory could be the fuel being low and it pinging but i dont know i wilfil it up and try again but i just shat

Myself

My mate told me the the power fc picks up any sort of vibration because its a crappy ecu and that it could be pickin up anything but its tru i did belt it to 6000+ in 3rd and thats the only time it went to 109 twice so im not sure what to do? The motor seemed fine though its just bugging me

[hesh12445]

And a respected tuner told

Me

It didnt go over 30 on dyno after it got belted for the tune so he said it shouldnt have an issue and he reckons its the low fuel could be the problem?

[Badgaz]

a bad batch of fuel can do this also. if you can borrow or get some knock ears you'll be able to confirm if it is actual detonation. My knock reading would show 30 but knock was actually audible knock ....don't always trust the factory sensors....the sensors are not powerfc...they are factory knock sensors....the power fc is not a crappy ecu...however it is old now and there are better ones....especially from a tuning point of view.

[Touge Kyousou]

My first motor and tune would occasionally knock up to high 90s with once going over 100... never showed high knock on dyno however.
That motor dropped a piston in a year or so...

Just sayin.

(you should really get it checked out, especially if your factory knock sensors are working fine)

[hesh12445]

Took to tuners today doesnt see a problem it might be the ecu its weird cpuld be spark plugs so i will change them tomorrow and will see how it goes i even dropped the boost Down to 14 psi and still gets to 90 so lets see if its the sparkplugs

[paulr33]

Covered in the Pfc FAQ. Cars can knock differently on road vs on dyno as it uses different load cells. The Pfc FAQ will show you how to troubleshoot this and to use the temp IGN adjust to confirm and fix the issue

[hesh12445]

How do i find this pfc FAQ?? Please mate thanks

[Ben C34]

http://lmgtfy.com/?q=power+fc+faq

[paulr33]

see here

http://www.paulr33.com/powerfc-faq/powerfc-faq.htm

[AngryRB]

my tuner said anything as high as 60 is a cause for concern and would need some ignition timing taken out,

on E85 I never saw more than 30 even with 25psi and a gt30, but still dropped a cylinder..

my advice is to be very careful, you could easily drop a cylinder, not that hard to blow a ring landing

from my experience, 3rd gear fried tyres and week later number 5 was down to 60psi

Edited June 25, 2014 by AngryRB

[johnj]

just a thought my gtr33 was tuned with pfc, ran perfect for about 3 months with knock of around 16-20. then for no reason started knocking to 60. called my tuner ,did the usual things, fresh fuel, checked plugs etc this didnt make it any better the last thing he told me to check was how clean the airflow meters were. they were filthy.i took them off and cleaned them with carb cleaner half a tin on each meter,let them dry and replaced them and knock back to normal give it a try for the price of a tin of cleaner, good look

[paulr33]

knock over 60 triggers the engine check light with the PFC

so apexi figured higher than 60 is something to be worried about