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megndylan
20-08-2011, 07:23 PM
hi i have an audi a2 53 plate 1.6fsi which has a misfire but gets worse when hot so i changed the fuel filter, airflow meter, coilpacks and plugs. Then i took it to the garage and they could not find the problem but its missing on number 2 that plug is black with carbon and the others are ok.. the error code is P1031 Intake manifold air control valve position sensor and the other one is p0302 cylinder 2 misfire detected, it also comes up with p0597 which is cruise control circuit open but the car does not have cruise control:confused: what is the next step ?? compression test? change injectors? anybody had this before or have an idea whats going on thanks

Crasher
20-08-2011, 08:40 PM
We could do with the engine code to help here, it should be “BAD” and no I am not kidding.

The manifold flap issue is common, you will find the vacuum actuator (part number 036 129 061 A) on the cars right of the inlet manifold and it will be broken at the end where it connects to the flap lever. This is a very complex process to replace (and it is so close to being easy that the poor design makes you want to weep) meaning the complete two piece manifold has to come off which also means removing the injectors which MUST have their seals replaced using a special VAG tool set which costs around £150. Then when the actuator has been replaced and the lower manifold reinstalled (which is a tricky operation to prevent the flaps getting jammed and bent) the system has to be set up in Basic Settings 04, Measured Value Block 142 using a diagnostic PC. The trouble is even then I have had other garages come to me with these engines (in various cars) not being able to set the unit up with full range not being achieved and to this day I have not found out what they have done wrong, thankfully I have never had this issue and I am sure it is due to not supporting the flaps during installation. It is not an easy job and one that I do not relish the thought of.

The misfire could be one of three common BAD issues, a failed coil pack, loss of compression due to a burnt out exhaust valve or a failed injector. Just pray to whichever God you believe in that it is a coil pack.

megndylan
20-08-2011, 09:59 PM
hi i changed the coil packs for new ones and it didnt work..

megndylan
20-08-2011, 10:03 PM
but would this only effect one piston?? if it was the manifold flap would it not effect all 4 ??

Crasher
20-08-2011, 11:49 PM
The manifold flap is ONE problem, the misfire is another, I never said they were connected.