Adjusting ALH Injection Pump Timing

In this video we will watch Corey from as he adjusts the injection pump timing on a 2003 Jetta TDI with engine code ALH.  He will overview both the mechanical adjustment and show the TDI Timing Graph feature of VCDS.

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Hi, I’m Corey from idparts and in this video I’l show you how to check and adjust the timing on your ALH TDI. There are three things you’ll need to check and adjust the timing on your ALH.

  •   The first is a VCDS Diagnostic tool.
  •   The second is a 22 mm wrench.
  •   The third is a 13 mm socket on a Ratchet.

  To adjust the injection pump timing we first have to get access to the timing belt.

  We remove the cover to the engine and the cover to the timing belt. We can just pull the engine cover off and remove the timing belt by unclipping these three metal clips. Slide it up, off, and out.

  The sprocket we’re dealing with to adjust the injection pump timing is going to be this injection pump sprocket right here. If you look you’ll see there’s a big 22mm nut and three bolts inside. These are the three bolts we need to loosen in order to adjust the pump.

  The first thing we’ll do is loosen those three bolts with the 13mm socket on the ratchet. It’s important that you just loosen the bolts—you definitely don’t want to take them out, and you want a little bit of friction left on the bolt. You don’t want them loose. Now, we take the 22mm wrench and put it on that 22mm big nut. Depending on your car, you’ll want to go either backwards or forwards on the bolt. If you want to retard the timing, push the wrench towards the car. If you want to advance the timing, pull the wrench towards the front bumper.

  After tapping the wrench in the direction you’d like to go, take the wrench off and tighten those three bolt. We’ll go inside the car and check where our timing is with VCDS.

  Here we are in VCDS. We’ll check the timing by opening up the engine control module. We need to go down on the right hand side to Basic Settings -04. We want to leave the group as 00 and just hit go. Numbers will pop up, but the most important thing we’re looking for is the bottom right TDI timing. Select your engine on the bottom right and click on the graph button. There’s a green line, blue line, and red line. This is your timing range. Close to the green line is advanced and close to the red line is retarded. On this car the timing is so advanced it’s off the chart, so we’ll have to retard the timing. Repeat the process until you get the timing correct. When you’ve gotten it right, completely close out of VCDS before shutting down the car.

  It’s important to be cautious when changing the timing not too move the 22mm bolt too far forward or back: it can be very hard to get the timing back in the zone you need it if you’ve overshot your mark.