Hope some of you can help

1999 1.8T AGU, engine suddenly changed note when idling after driving home yesterday, drove round the block and no pull and rough idle, this does not change whether hot or cold.

Disconnected MAF no change

Swapped coil packs between cylinders no change

Had local garage check for fault codes none found

Local garage report problem is with cylinder no.3

Plugs checked OK

Compression checked OK

This seems to leave the injector or the wiring to the injector

Anyone have any input on how to check injector

Are the injectors a common failure

Car is old but only 50000 miles all done by me from new

All input welcome

Many thanks

Coolant temp sensor.

Boost pipe? Every so often mine will pop the pipe off the dump valve never shows any codes

I'd go for boost leak popped off too, or split at 12 years old. Would have expected it to show a fault code though.

Does it sound any different? If a boost pipe has come off, you should be able to hear the turbo whoosing it's head off.

Do you have a missfire on cyl 3 or just idle problem?

if its missfiring on cylinder 3 its probably the ignition output stage module on the back of the airbox playing up... its very common for them to overheat and cylinder 3 always goes first!! the main cause of them overheating is people who fit a cone filter and leave the module flapping around in the engine bay, normally the airflow in the airbox cools the heat sink...

hth

edit: i seem to remember these modules being well over £150 from skoda, but you can get aftermarket replacements from gsf

Exactly,That's why I asked him...I had the same problem and the ignition module was broken on cyl 3.

I went for the aftermarket HUCO(Germany) is the cheapest solution,about £70

Skoda asked £170 for OE Bosch

if its missfiring on cylinder 3 its probably the ignition output stage module on the back of the airbox playing up... its very common for them to overheat and cylinder 3 always goes first!! the main cause of them overheating is people who fit a cone filter and leave the module flapping around in the engine bay, normally the airflow in the airbox cools the heat sink...

Hey Teflon Tom, what is the Skoda Part Number of that Ignition Output Stage Module.

THX

Isaac

Hey Teflon Tom, what is the Skoda Part Number of that Ignition Output Stage Module.

THX

Isaac

There are a few different part numbers tbh, but they all relate back to the same thing.. If I recall correctly they are only used on agu and apu engine codes but the part number differs depending on which vehicle it's fitted to but it is all the same part...