Injection Start Timing: Adjust with Diagnostic Tool?

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Hallo, ich habe mit dem Diagnosetool den Spritzbeginn gemessen. Im Leerlauf 2 Grad, sollte aber zwischen 6 und 13 Grad vor OT liegen. kann man den Spritzbeginn biem 1z TDI mit dem Diagnosetool einstellen? If so, how?
Thank you!

Translated on 08-09-2026, 13:24.

Hello,

Are you sure about the 6-13° BTDC? I think that's typical for industrial engines, but my engine has an AHF (Air-Fuel Mixture) of about 2° BTDC at idle (without any ECU adaptation).
Based on my experience, the engine starts to make a noticeably louder knocking sound at 6° BTDC (Before Top Dead Center).

Best regards, Rainer.

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Hello Rainer,

I have an installation manual for a VAG 1551 for an AFD engine. It states that the injection timing should be 6-13 degrees before top dead center (BTDC) at idle.

'Under full load, I've measured up to 11 degrees on my engine. The manual states that it should be between 6-13 degrees under full load. There might be an error in this manual. If you also have 2 degrees, I'll leave it as is.'

It actually runs smoothly and quietly when idling.

Translated on 08-09-2026, 13:27.

Hello,

and how do you determine that the target values of another engine should be suitable for your engine?
/viewtopic.php?t=327

Best regards, Rainer.

Guest Free account, no CAN development support

Read the value (fuel temperature > 40 degrees) and then loosen the pump. Loosen the front screw last. Then, turn the pump until it reaches the target value, and tighten the screws. Don't forget the screws on the fuel lines.
If the start of the funding period is delayed again, your pulley on the crankshaft is likely loose. This could soon lead to engine damage! Immediately remove the belt and check the crankshaft flange (the ribbed pulley may also be damaged).

Furthermore, I don't believe you're adjusting the start of the injection process... at most, you're adjusting the start of the flow... and the delay between those two is what's referred to as the injection delay.

Best regards, Jan.

Translated on 08-09-2026, 13:29.

kasper wrote:

Furthermore, I don't believe you're adjusting the injection start, but rather the pump start... and the delay between those is the injection delay...

Hi, that's incorrect. The needle lift sensor allows for the determination of the start of injection, and this information is also provided by the engine control unit.

Best regards, Rainer.