Engine cuts over 1,2 bar

[S2sedan]

Hi,

I`m new here, live in Brazil, and bought an S2 sallon a week ago. I left the car at the garage for a inspection, repaired some faults and asked for new eprom with more boost on it. I`ve noticed that the car cuts when the boost try to past 1,2-1,3 bar. At 3500-4000rpm.
Does anybody knows what happens. The car still running on 95 oct. gasoline

[Dr H]

That sounds like the overboost protection kicking in.

Could have an air leak somewhere.
What type of chip was fitted?

[S2sedan]

Sometimes it goes, sometimes don`t ... I only can get over 1,2 bar, when I start accelerating about 2500 revs, then the boost try to pass 1,2 bar. I thougth it might be MAF or something like that . The fail is very simmilar to that when you have open spark plugs. The new chip I have is mapped by a local garage ... I don`t know the program or parameters he uses.

[S2sedan]

How do I know if is the overboost protection ???
how to detect it ??
VAG can do it ??

[porkkis]

Too low octane.

[Dr H]

Overboost protectioin feels like a compete cut of power.

Does the car cut out completely or does it fell like it's misfirng or as you say open spark plugs.

If it is like the open sprak plug then I think Prokkis is probably right - too low octane fuel.

[S2sedan]

Overboost protectioin feels like a compete cut of power.

Does the car cut out completely or does it fell like it's misfirng or as you say open spark plugs.

If it is like the open sprak plug then I think Prokkis is probably right - too low octane fuel.

No, It fill`s like missfiring, I don`t think it low octane, because I have other turbo car running at 1,9 bar with this crap gas that we have here anda have no problem...

Thas why most of time we choose to run on alcohol... its third price and the comb is much coolder than our gasoline. The only problem, is to feed. You have to use at least 30% more comb to get the A/fuel ratio.

[Doug_RS2]

If you just get a misfire everytime you go over a certain level of boost it is most likely a coilpack not working/going bad.

HTH

[Dr H]

@ Doug Good point, you've BTDT I guess.

@S2Sedan is the chip mapped to be used with 95 oct?

[S2sedan]

Iep...

I don`t know what coilpack is .... (the translation) can you please explain me what it does and I will know what it is in portuguese

[Doug_RS2]

The part on top of the spark plugs that supply the high voltage to produce the spark.

There are 5 of them bolted to the cover you lift off when accessing the spark plugs.

[S2sedan]

The part on top of the spark plugs that supply the high voltage to produce the spark.

There are 5 of them bolted to the cover you lift off when accessing the spark plugs.

OK, thanks, now i know what you are talking about... i`ll check it

[RSBLURS2]

If you just get a misfire everytime you go over a certain level of boost it is most likely a coilpack not working/going bad.

HTH

Could this be the prob with mine? I picked up my car this morning following a service which inc. replacement sparks and the acceleration felt really lumpy on the way up to Dundee. I took it in to the garage on my way home and took a technician out for a spin to check it out (I thought spark plugs) and no problems other than one "misfire" in fourth gear. As I was in the middle of town I could'nt open it up much as 30mph limits only allowed 4th gear and even then I ran out of road. He plugged a diagnostic up which showed no probs but felt the jump - I've ordered a new DV and fuel filter which did not arrive in time for the service - could either of these also be a cause? It happens above 3000rpm and for some reason does'nt seem to occur in 1st, 2nd or 3rd.

[S2sedan]

Could this be the prob with mine? I picked up my car this morning following a service which inc. replacement sparks and the acceleration felt really lumpy on the way up to Dundee. I took it in to the garage on my way home and took a technician out for a spin to check it out (I thought spark plugs) and no problems other than one "misfire" in fourth gear. As I was in the middle of town I could'nt open it up much as 30mph limits only allowed 4th gear and even then I ran out of road. He plugged a diagnostic up which showed no probs but felt the jump - I've ordered a new DV and fuel filter which did not arrive in time for the service - could either of these also be a cause? It happens above 3000rpm and for some reason does'nt seem to occur in 1st, 2nd or 3rd.

Its just like that... do you know where the diagnostic plug is ???

[RSBLURS2]

Its just like that... do you know where the diagnostic plug is ???

Sorry, not exactly - I was'nt paying attention. I think it was by the fuses under the bonnet in front of the steering wheel (RHD) but can't be sure. It is not the fuel as it is Optimax. Hope I find out soon !