Pinking!

[Glen Chamberlain]

Iam have a running problem which makes the car hesitate @ high RPM under load. Iam suspecting low fuel pressure and am awaiting some unions so i can adapt my oil pressure tester.

Ive also noticed it pinks! just like you've put a marble in each cylinder! Between 6-7K.

What causes pinking apart from being too advanced? It should control that with the knock sensors way before i can hear it shouldn't it? Could this also be caused my low fuel pressure?

[A6 AVANT]

Hi Glen, Hmmm tricky one. The only experience I can relate to it is when we had a Tipo 2.0 16v in our garage that pinked only at certain speeds and revs and after checking it over and speaking to the dealer the fault was caused by cheap fuel i.e. supermarket juice. The guy filled up next time at a mainstream petrol station BP/ESSO/SHELL etc. and it disappeared. Worth a try? If you are using Super U/L maybe they filled tank up with normal by mistake? Try a different station? Can't imagine low pressure being your problem but might be worth testing. Would have thought low pressure would cause problems before those sort of revs?

[audiman]

This is obviously an ignition advance prob. The knock sensors would normally pick pinkng up way before you can hear it from the seat! Glen is yours standard? If it is then cheap fuel would be OK in it, ECU is programmed to retard the ignition. Any fault codes??

[S2central.net]

Pinking is too much advance or too lean a mixture.

Have you checked fuel pressures yet - with vacuum and boost on the FPR ?


Cheers,

Paul

[AbsS2]

what is pinking?

[newsh]

Originally posted by AbsS2
what is pinking?

Also known as pinging (US) and tinkling (my mum)

Its when the fuel explodes instead of burning in a "controlled" fashion. Diesels do it on purpose When pinking gets bad it is known as detonation and it will wreck an engine, holes in pistons etc. Normaly pinking happens at low rpm high load. Detonation normaly at high rpm, high load.

low octane fuel burns more easily than high octane and therefore explodes more readily. Low octane fuel will actually give you more power as long as it doesn't pink.

I know the ecu should sort it out but I'd still try a tank of Optimax just to find out, maybe you got a really bad tank full and the ECU can't keep up?

Pull codes.

When my UR was doing a lot of pinking it turned out to be the MAP sensor.
(which was a drag because you can't buy one for a UR box, Hitachi deny all knowledge of the part)

[Dr H]

Glen

Reading your previous posts on turbos getting red hot maybe there is a pattern forming here. Lean running would cuase the turbo to get hot and pinking and you say you get amazing MPG.

Could be wrong but you never know.

Leigh

[porkkis]

Of course low fuel pressure would make the engine ping. Lack of petrol at higher revs makes it run lean. Running lean mixture pings easily.

[Mihnea]

Originally posted by porkkis
Of course low fuel pressure would make the engine ping. Lack of petrol at higher revs makes it run lean. Running lean mixture pings easily.

BS, I've ran a few engines so lean they would have pinged like church bells if pinging had been so much related to the mixture, pinging only happens at mixtures leaner than 16:1, I've already run engines at 15:1 with EGTs in excess of 900 degree C post-turbine (the power they made was amazing but it's all but recommended to do so) with no pinging detected by the ECU, nor by the microphone I had in the engine bay. Of course, don't ever do that, I was doing it on purpose and had been asked to do so by my friend in order to find out how prone to detonation/pinging was an engine running a really lean mixture. After I saw EGTs higher than 930 degree, I've stopped and set it to "normal" mixture again, 13.8:1 made it run wonderfully with peak EGTs of 840 degree C post turbine.

[Glen Chamberlain]

Well thanks guys! Its no longer stock only for an RS2 turbo and re-map.
Ive tested fuel pressure and this is what i found!(I belive an ABY to be 4 bar above maifold pressure!, 3B 3.5 bar above)

At tickover = 3.8 bar Fuel pressure
Engine stopped = 4.0 bar Fuel pressure
With 0.5 bar of simulated boost = 4.7 bar Fuel pressure
With 1.0 bar of simulated boost =Damm didnt right it down!!!
With 1.6 bar of simulated boost = 5.6 bar Fuel pressure

to me that seems ok!!
I have'nt tried optimax or super yet but just brimmed it with regular 10 miles ago? dam!

Ive had a gas test today! FREE and basic
At tickover it was showing lambda 1.006
and at 3000rpm lambda 1.001? Iam sure that will not count for much but it was free and available so i took it! Hydrocarbens was 0 and i cant rember the Co?

[Mihnea]

Hmmm, what fuel did you have in it so far???? What's regular?

Anyway, no car with a chip should tank less than 98 RON, under no exception, and if it has to be done, avoid using WOT as much as you can!

Mihnea

[Glen Chamberlain]

Ive always run it on 95 ron but never advised otherwise with the chip? But the next tank will be 98ron! ?

Is there any additive i can add to this tank to help untill i get chance to fill with 98?

[Mihnea]

WOW!!!!!!!!!! even a stock S2 will work better on 98 RON (i.e. make stock HP and perform ok as well as use less fuel) and I always advise people to use 98 RON in their cars, even if they are bone stock. And I know of someone who's blown a head gasket on an ABY because he was using 95 RON and driving the car very hard, so you never know with 95 RON...

So, next tank should be 98 RON, if you want more power, get yourself some toluene and throw 10 liters of it in the tank, this should add some more octane, otherwise, all octane boosters only increase the octane rating by 0.something, like going from 95 to 95.3, which I can't see any point to do that!


Cheers,

Mihnea

[Glen Chamberlain]

Well Mihnea i'd be stupid not to take your advice so i'll brim it with 98 next time!

I have, well girlfriend has now a 97 polo 16V which i ran for 12 months on 95 = no probs 1 tank of super and it was noticably more slugish, next tank was 95 and all was fixed! A week later another tank of 98 and again it was slugish! At the time i tried so hard to work out what it was cos i was convince it couldn't be the fuel? but it was!:confused: :confused:

[audiman]

Originally posted by Mihnea

Anyway, no car with a chip should tank less than 98 RON, under no exception, and if it has to be done, avoid using WOT as much as you can!

Mihnea

Ah, ****! Must make a mental note to only use 98RON.