timing ??

i tired setting it, got it finally set. a week later it shifted . tired to readjust now no matter which way i turn it just shows 38 with no change advance or retard it. I checked all setting all on the mark . could computer be going bad?

What car is this on? How are you checking it?

mk4 tdi must loosen up the pump sprocket and change it by 1mm and re check it.
1mm to front of engine means advance timing.

1.9 alh had timing set. worked ok. then went to check it a week later to fine tune. with graft it stays at 38 no matter which way i turn pump. I even put a different pump on re set it all up. vad com set reads 38. I put old pump back on no change. could something in computer be going bad [1999.5] that it stays right there does on move[float] moving 5 deg either way. It just started to smoking like a pig. that's what made go back to check it again.

Alh you must adjust the pump sprocket not the pump it self only on afn . Alh mk4 adjust the sprocket on the pump loose it 3 bolts and adjust by 1mm steps and check it

i know to loosen 3 bolts & turn with 22mm wrench.[ I did have it set at middle line before] I did that both ways with no change on vad com. I don't know could it think limp mode safe setting , but with full power. what would factory limp mode timing be?