How to make a DIY injector puller for use on various older VW petrol engines

29 Nov 2015

In this post I’ll explain how to make an injector puller for use on various older VW engines which use mechanical fuel injectors, more specificaly the Bosch 0437502045 injector. They pop into the injector sleeves and are held in place by thick rubber O rings. Theoreticaly they should pop out easily, but in reality the O rings get rockhard and they’re impossible to get out. VW offers a tool for this, number 1123/4, but my DIY puller only cost 16€ (which is less than the tool would have cost including shipping), is a lot stronger and has more leverage, also works for the 16v engines and can be made using only stuff you’ll find in any hardware/DIY store.

The materials

1x 25x25x3cm corner brace
2x 50cm long hinges you’d use for garden/shed gates
1x M8 L35 bolt
1x M8 nyloc nut
*4x 8.4x16mm washers

The tools

Drill
Drill bits: 3mm, 6mm, 8mm
Angle grinder with very thin cutting disc and a 2mm grinding disc
Calliper
2x 13mm wrenches to do up the bolt and nut
A long bit of metal box section
Felt pen
And the most important: ear and eye protection! You only have one set of ears, and one set of eyes, take good care of them when working with power tools!

Step 1: cutting the 90° bent strip

Cut 1 leg of the corner brace off, but leave +/-2cm like shown in the picture.

Step 2: drilling the injector slot

Drill a hole in the center of the 2cm long part of the corner brace, the part you just cut to length. Begin with a 3mm drill and then use the 6mm drill. Now cut trough to the hole to make a slot, like shown in the picture.

Step 3: making the metal thinner around the slot

Use a calliper to mark 14mm off around the slot. We will have to grind this bit back a bit so the metal gets thinner. If we didn’t do this it wouldn’t fit around the injector because the metal strip is too thick. By only grinding back a 14mm wide bit we keep some strength in the tool.

Step 4: adjusting it untill it fits around the injector

This is how it should look when you’re done. I suggest not being too hard with the grinding. Grind a bit, test fit, grind a bit, test again, etc. You will also have to adjust the width and depth of the slot a bit. So combine adjusting the slot, and grinding back the area around it while test fitting the tool.

The slot should go under the fuel line connection on the injector, between the injector body and the fuel line connector nut.

Step 5: preparing for twisting the metal strip

5 to 10cm from the top of the metal strip you need to mark out an area of 5cm long. Here the corner brace should be made smaller by 7.5mm on each side as shown in the picture. This is needed to make it easier to twist the corner brace. Be careful here, it takes some grinding to remove 7.5mm, there’ll be a lot of sparks.

Step 6: twisting the metal strip

Now we need to twist the metal. Put the brace in a vise (if it wasn’t already there for the other work you did on it), the start of the smaller bit we just grinded back should be flush with the vise, the smaller bit should be above the vise. To twist the corner brace I used a 1m long 2x4 bit of box section with two other strips put in one end. The corner brace then goes between those two as seen in the picture. With 1m of leverage twisting the brace goes quite easily. You should twist it by 90°.

Step 7: dressing up all the cut faces to remove sharp edges

This is how it should look now. Dress up the cut faces to remove any sharp edges, this will make working with the tool more pleasant. You might want to trim back a bit the bit where the slot is, untill the tool fits easily around all the injectors. This is necessary on 16v engines or you won’t get the tool between the inlet manifold, and then around the fuel line connector nut, without bending the fuel line.

Step 8: connecting the two hinges

To get leverage to pull the injector out we need those two hinges. Use the hole on the other end, the one you normally use to screw the hinge to the gate. You’ll probably need to make the holes in the hinges and the corner brace a bit bigger, use the 8mm drill bit for this. Use washers and a lock nut to enable smooth rotating of the lever arm. The order in which to use the fasteners: M8 bolt, washer, hinge 1, washer, metal strip, washer, hinge 2, washer, nyloc nut.

Below you can see how the tool should be used. This a 16v Golf mk2 in the pictures, but the tool also works for a lot of other VW petrol engines with Bosch Jetronic systems and injectors that can be pulled out. The tool I made is for the Bosch 0437502045 injector, as mentioned before.

Happy working!