Hi everyone I've read lots of posts on this all seem to have same problem when left for a long period of time 4hrs etc car struggles to start it turns over fine but it like its not catching I let glow plug light go out then turn if I put glow plugs on a couple of times it's a little better not much but it always starts second turn ?
After reading other posts seems it could be
2 temp sensor
4 glow plugs
5 pump timing
I'm going to replace temp sensor first as its cheapest and easiest could someone please post a picture of exact location
Car is a 2002 A6 2.5 tdi