Poor start TDI when engine is cold

the grim reeper

A2OC Donor
Hi All

When i first start the car either first thing in the morning or 8 hours or so later when leaving work, the car starts fine (nearly first turn) but then runs very lumpy like its on 2 cylinders (ABS light and yellow triangle warning lights on dash) after about 10>15 minutes of just letting it tickover to warm up. Turn it off and start again it runs fine no lights no hesitation drives normal. Its done this for a couple of days now just in the mornings but now its doing this after work too. Checked the glow pugs today 2 where faulty so swapped all 3 but no joy, we did notice that there was no voltage coming down the cables but was unsure if this because the engine was warm and so wasn't showing voltage??. Any clues where to look next Fuse, relay or is this run from a module??? any help much appreciated.

Phil
 

the grim reeper

A2OC Donor
Thanks Pete we have the latest Audi software/OS at work but the A2 is to old for this as it only read's basics, so need to get someone local to give it a scan
 

the grim reeper

A2OC Donor
Hi guys had this scanned today code came up as 18075 cylinder 2 electrical malfunction (N241) done some digging on here and came up with injector harness. Just very strange it only happens when cold ?

Phil
 

audifan

A2OC Donor
The injector harness has a very hard life. Inside the top of the engine it is soaking in oil and heat. When warm the resistance between one of the connectors to the injector reduces and proper contact is made. When cold the resistance is higher either due to the connector being loose or oil insulating the tired wiring. The diesel engine is very thermal efficient, that is why it takes a long time to warm up, but that heat healp toast the injector loom. Not a big or expensive job, but do replace it rather than try to clean it.
 

the grim reeper

A2OC Donor
Yes ordered today £70 +vat. Well it's been a long time in there just coming up to 150K so its had a hard life in the top of the engine.

Phil
 
Top