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-   -   PowerFc showing knock of 72!!!!! (https://www.scoobynet.com/drivetrain-11/414600-powerfc-showing-knock-of-72-a.html)

SamUK 27 March 2005 10:17 AM

PowerFc showing knock of 72!!!!!
 
Pavlo seems to be away...so untill his retun can someone please answer my quesitons...

My cars been driving great for a while...with the following setup on the AVCr:

1.4bar, dropping to 1.3bar at 5000rpm onwards
69% Duty, dropping to 65% 5000rpm onwards

Start Duty Gear 1: 10
Start Duty Gear 2: 6
Start Duty Gear 3: 2

Boost is held very well and drops fine, untill afew days ago, where i had to increase the duty all over by 4% up to 73% to hold the boost at 1.4 bar and drop to 1.3 bar.

This may have been due to the weather change, as last night i reduced it to 70% to hold boost.

KNOCK:
My Pfc, only in 3rd gear between 6500rpm and 7000rpm hits a knock between 32 and 72 every time...not sure why this has started happning...though understandable that maybe a degree needs to be taken off the engine advance...why all of the sudden? :cuckoo:

Also:
I am sure that my Boost soloniod, used to make a ticking noise if when starting the car i let go of the key too soon and the car does not start...it has also stopped doing this...

Any thoughts welcome... :idea:


--Sam

stevebt 27 March 2005 11:28 AM


why all of the sudden?
if your messing about with your map settings !! what do you expect

SamUK 27 March 2005 01:48 PM

I don't recall saying i have messed with the map... maybe indicated that i know how it would be resolved as i have some form of understanding of how the map works!

Thought someone here would indicate what would cause this as Paul is away at present...

Just to clarify:
No map changes have occured since the last map....few months ago now..

SiHethers 27 March 2005 05:14 PM

Sam

Check you don't have a leak in the hose to the AVCR MAP sensor, which is causing it to under read. I can't believe a change in weather would lead you to need to increase all your duties by 4%. Do you have the original MAP sensor still in the car, and if so read what boost it is recording with the commander.

Secondly, do you still get a knock count that high if holding that rpm but off boost. This will help you determine whether it is genuine knock and not an external noise such as a heat shield vibrating.

Cheers

Simon

SamUK 02 April 2005 04:50 PM

Checked the above and all seems ok..

Drove my car today, and i am now seeing knocks in the region of 72 in nearly every gear but 1st... :(

Could this be caused by the weather change?

FB Tuning 02 April 2005 05:36 PM

Maybe you should pull a couple of degrees of timing out of the map, or lower the boost a bit until you resolve the problem?
:)

SamUK 02 April 2005 06:41 PM

Just waiting on a reply back from Pavlo, to find out what numbers to reduce...

Though boost running at 1.4bar, even with the Duty reduced to 65% still same issue...though off boost seems ok..

What lost me is, the other day i noticed this happning in 3rd gear only at 6500rpm, now almost every gear..

Surley all scoobies are not like this...i know that heat does the turbo no good...but this just takes the pi$$....

Silly Question:
I assume reducing the timmnig will effect the power too..?

stevebt 02 April 2005 07:37 PM


Silly Question:
I assume reducing the timmnig will effect the power too..?
once the mapping has been done to my car i dont touch a thing via the commnader duty cycle or anything :eek: and guess what i never see any knock activity :) if you alter just one thing on your settings and your engine blows all the mapper has to do is check back to his log and see that it has changed , and i mean just by alterering the idle limit you are interfering with a set figure. so blame is then on you

SamUK 02 April 2005 08:15 PM

Well the commander has never been touched..Boost control figures are adjusted to suite the weather conditions...otherwise boost spike occur, unless you totally depend on the self learn of the unit..which i and i am sure many others here do not..

Can someone please give me a more of a productive thought as what can be wrong rather then who is to blame!

stevebt 02 April 2005 09:03 PM


Can someone please give me a more of a productive thought
:confused:

ScoobyDuck 02 April 2005 09:11 PM

try setting the boost down to something sensible, like 1bar and see if it still does it.
if its only doing it at higher boost - its probably in need of a tweak somewhere.

but if it just gets noisier and noisier as the revs rise (use the graph function) then it could be something else.

loose knock sensor ?
some other metalic noise generated by something rubbing / vibrating ?

knock usually only shows as a spike of 20-30 increase in the value, if its raising gradually and constant, id say it was something else.

so try knocking the boost and let us know whats happening....

Steve

DeanF 04 April 2005 11:44 AM

As Below, Could be mechanical, Drop the boost & see if it still knocks the same, If det it shouldn't really, I would then get a set of det cans, Stethascopes to listen to the engine before something potentially goes POP !!!!

Justa thought whats the Afr reading !!! LEan / Rich ??


Dean



Originally Posted by ScoobyDuck
try setting the boost down to something sensible, like 1bar and see if it still does it.
if its only doing it at higher boost - its probably in need of a tweak somewhere.

but if it just gets noisier and noisier as the revs rise (use the graph function) then it could be something else.

loose knock sensor ?
some other metalic noise generated by something rubbing / vibrating ?

knock usually only shows as a spike of 20-30 increase in the value, if its raising gradually and constant, id say it was something else.

so try knocking the boost and let us know whats happening....

Steve


Peanuts 04 April 2005 11:56 AM

any fuel cut with that Sam?
on my pfc I used to see high knock level but it was due to fuel cut, incidentally, it was a 73 count at its worst.
I managed (from discussion with Andy and Mark) to trim a bit from the start duty and that made it play the game, so to speak.

Can you hear any Det at all? the ol breaking glass/death rattle should be quite audible.
can you turn the avc-r to run in 2 channel mode, set the two channels to be Sol. duty and boost.
get it running in graph mode and record a few gear changes, at least then we might be able to get an idea if anything is wrong with your boost solenoid or if the boost has changed at all.
if you have a camera phone you could take a pic of the graph you have recorded....

Andy

SiHethers 04 April 2005 02:37 PM

Sam

The quickest way to resolve this is to go into the commander, Settings, Ign/inj, and apply -5 to Ign Corr. This will retard your whole ignition map by 5 degrees. The car WILL feel flat doing this but you will not do any damage as a result of this. Set the commander back to Monitor, 2 channel, rpm and knock, activate peak hold function, then switch to graph mode. Then try and replicate the conditions above, ie 6500rpm in whichever gear you see it in. After a WOT run through this rpm region the problem occurs, hit the < (left) arrow to freeze the graph display. As scoobyDuck says, det will be apparent as spikes in the trace. A gradual increase is more likely to be external interference. Check the peak hold to see what the max value you get is.

If it still occurs after retarding the map 5 degrees, then it is very unlikely to be det, and you need to be searching for something that is vibrating or rubbing and getting picked up erroneously by the knock sensor.

Hope this helps define the cause.

Simon

PS the applied retard will be removed automatically when you switch the ignition off.

SamUK 05 April 2005 10:43 PM

Guys thanks for all the input, Paul also gave me some numbers to reduce from the map...Just little fed up of the car at the mo, so is parked up in the garage whislt my brother is on Holiday...so making use of his Audi... :D

Will try these things hopefully next week...

Sam


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