2002 S3 8L power loss, stalling, misfiring - Help please

[86fran]

Mornin all,

Last wednesday my 2002 S3 went a little funny on me.

I was sitting at a roundabout and when I went to set off the car struggled as soon as I hit the throttle, by struggled I mean the revs would drop very quickly causing the car to stall out. This happened a few times and when I managed to get the car going it sounded like it was not firing properly... and the check engine light came on followed by the ESP light.

I turned the car on again and these lights are off but the car still sounds like it is missfiring/not running properly

Bought myself a OBDII reader and got up the following codes:

17608 - N249 valve
17743 - Engine torque monitor - level exceeded (possibly as I had to keep revs high as I was to stop the car from stalling out?)

Am i right in thinking i need to clear these codes first and double check that they are new ones?

I have read a lot about the common coilpack issue on these cars, should this not throw up a code if it was these at fault?

any help would be much appreciated

 

[Andrew@A.L.D]

• Rough Running At Idle: MAF, Ignition Coil, Spark Plug, VAC Leak, O2 Sensor, TB, CTS
• Missfires under Boost Flashing CEL: Ignition Coils, Spark Plugs
• Running Rich: Boost Leak, MAF, O2 Sensor, Coolant Temp Sensor
• Running Lean: VAC Leak, MAF, O2 Sensor, Fuel Filter
• Low Boost: Limp Mode, MBC, BOV, DV, Boost Leak, N75
• High Boost: MBC Setting, N75, Spark Plugs, Ignition Coils
• Cold Start Problems: MAF, Spark Plugs, Fuel Pump Relay, CTS
• Poor Gas Mileage: MAF, CTS, O2 Sensor, AIT Sensor
• Cat Efficiency Below Threshold: Down pipe, CAT, Rear O2, RACE FUEL
• No Start: Battery - ECU, Fuel Pump Relay, Ground
• Start For 1 Second Stall: Immobilizer
• Overheating: Waterpump, Thermostat, Head Gasket
• Oil in coolant: Oil Cooler, head Gasket, Water Wetter
• Dies While Driving: Timing belt, Boost Leak, MISC
• Shorts To ground CEL: Fuel Pump Relay, Bad Grounds
• Oil in your IC/IC piping: Check your PCV system

 

[86fran]

Thanks for that.

Just been out and checked the car over properly.

I checked over wiring/electrical connectors and vacuum lines etc, couldn't see anything obvious hanging off. I double checked the car had the N249 bybass which it does and it is plugged in with good wiring so unsure why it has thrown this code.

I started the car up and it was hunting baldy on idle and missfiring too.

Removed the coils and spark plugs and noticed a lot of unburnt fuel on the spark plug in cylinder 1. I'll be ordering up a set of coils and spark plugs to replace these ones and hopefully that'll cure the problem.

 

[86fran]

Well, some progress on this issue!

Dodgy coilpack is replaced along with new plugs which has solved the misfiring.

Now it seems my MAF is dead... Rough idling with it plugged in, fine when its unplugged... I tried cleaning it and refitting with no success, is it ok to run the car without the MAF plugged in until I source a new one?

Thanks

Fran

 

[<tuffty/>]

Dodgy MAF most likely caused your torque limit fault code... I had this recently with mine... new MAF fixed it... you can run without a MAF connected but it will affect MPG a bit...

<tuffty/>

 

[Mr Footlong]

Sorry for the slight derail but I have a MAF-related question on these too. Due to cable tightness going to the MAF, I moved things around yesterday at the same time as modding the wing feed pipe slighty and as it stands, the MAF is upside down, as in the plug is at the bottom, not the top.

I don't expect there to be any issued with the MAF physically pointing upwards in the housing but worth asking?

Thanks.

 

[86fran]

Thought I'd update this as the car is working fine again

Needed 1 new coilpack (and a new set of plugs for good measure) and a new MAF. Seems to be working fine now which is all good

 

[badger5]

Sorry for the slight derail but I have a MAF-related question on these too. Due to cable tightness going to the MAF, I moved things around yesterday at the same time as modding the wing feed pipe slighty and as it stands, the MAF is upside down, as in the plug is at the bottom, not the top.

I don't expect there to be any issued with the MAF physically pointing upwards in the housing but worth asking?

Thanks.

I've heard it should be above horizonal, but can only think this is to prevent moisture from collecting on the maf hot film element
cant recall where I heard this tho..

 

[Mr Footlong]

I had thought of something along the lines of that but hadn't looked at the actual element to decide for myself, makes sense. I will cut a small channel in to the top back ofyour heatshield to let the MAF sit the traditional way up and route the cable through.

This is an odd one tbh as the MAF sits happily behind the heatshield on the LCR which is the norm I believe yet really wasn't happy when put behind the shield on the S3, was really squashed up at sub-90 segree bends at for the turbo inlet and MAF end if you follow. As a result of this AmD fitted it in front of the shield as the fitting was noticeably better. I suspect that may have been sorted with a bit of cutting back of the TIP at the turbo inlet end as you do warn I believe. I double checked this myself by refitting the MAF end at the weekend, hence why the MAF lead is now going around the bottom of the shield as it was sitting over the top between the bonnet padding and the rubber seal you put on the shield.

The TIP is slightly stretched past 90 degrees at the MAF end when set up like this so I have reformed/toughened that bend up with a clamp and it is working perfectly so no worried on that front.

Anyhoo, waffle over, thanks for the reply