2.5 TDI high pressure fuel pump
 

Just replaced timing piston on 2.5TDI following instructions from here https://www.audi-sport.net/xf/thread...ed-dyi.202862/.

Mine however my is 3 piston type and I did note take notice which way the 3 star washer goes in. Tried searching on google but could not find. Anyboduy happen to know which position it should be when pump is locked?

http://forum.a8parts.co.uk/attachmen...1&d=1526144354

Have had no luck finding out which position washer should go in so will need to trace distributor part of pump alignment to the cylinder.

I know usually when engine is locked it is cylinder 1 in TDC but for some reason I had it back in my mind that for 2.5 V6 TDI it was cylinder 3. I tried to look for references in Elsa but could not find anything, it just says TDC. I guess I will assume it's cylinder 1 as usual unless somebody knows otherwise.

Have you tried TDIclub.com? Its an American forum, but there are a few Europeans on there who know the V6 engines.

Well it was a bust.
I aligned pump for cylinder 1, fitted to car, while fitting noticed that locking pin on pump was not in correct position, about 30-40 degrees out, but fitted it in this position anyway as I put the pin in when crankshaft was locked and secured it in place with duct tape so it was in the same position it came off car. After lot of cranking it started but was running a bit rough. Pressed accelerator, no change. Checked VCDS, it was showing injection qty 20mg/str instead of expected 3-6. VCDS does not show injection angle until engine has warmed up to about 78C and I was not going to run it for long enough to warm up wiyh it not working correctly. I thoght maybe the pump have moved out of position somehow even if it seemed very unlikely with a pin secure with a tape so that it could not fall out. So I reset pump belt timing with a pin in correct position- no start at all so that must be wrong. i though i have put the washer in pum in wron position so took pump apart again, moved washer re-assembled, put in the car - no start. Repeated everything with a washer in 3rd position still no start. If I loosen pipes at injector there is fuel coming out as I crank engine in all 3 washer positions but no start. Might buy a cheap pump off e-bay for £100 just to take it apart and to check the correct position, try moving belt couple of teeth at the time until it starts

I did eventually out it together after buying another pump. It turned out the position I tried first was the correct one I just gave up cranking too soon due to not being sure if it's right. I was expecting it to be similar like after filter changing but it needed way more cranking. Even after sucking fuel through the pump from the return outlet using vacuum pump it took forever to bleed it. After I was sure of the correct it's the correct position I cranked the hell out of it, flattened battery, put it on charge and continued next day. Eventually it started, was running very lumpy and did not respond to accelerator pedal. Injected qty was showing 20mg/stroke in idle (should be 3-6) and that was limited by smoke map so that's why it did not do anything pressing accelerator. After about 5 min injected qty started to drop and it started to respond to accelerator pedal. After about 15 min it was pretty much where it should be but still a bit lumpy idle. Timing was spot on checking with VCDS. After a bit of driving around it improved but was still a bit lumpy in idle sometimes on cold starts but seems to have gone away now after couple of weeks.