PeachParts Mercedes-Benz Forum - View Single Post - Woo-hoo, It's Alive!!!!

psfred · #14 06-21-2007, 11:42 PM

If the injection timing isn't very close to what it should be, you will get horrible knocking (if too fast), low power, and lots of smoke at either high or low speed.

Worse, it WILL run 180 degrees out (fuel injected at the end of the exhaust stroke, I think), but will run very badly, knock like crazy, and refuse to develop power.

There are some IPs that have the mark on the driveshaft 180 degrees out, don't know which ones, but it's a known problem.

To set timing, you need either a factory drip tube or a substitute (rubber hose will work if you cut the end at a slant). Remove the #1 injector line, take the pressure valve holder off the IP, remove the spring and small steel valve (don't lose them!), reinstall the pressure valve holder, and install the drip tube, or your rubber hose. Bend the hose around so that the sharp point is on the bottom and pointed down.

While maintaining pressure in the IP with the hand pump, slowly rotate the engine toward 26 degrees BTDC on the compression stroke for #1 cylinder. When the fuel flow out the drip tube drops off sharply, the plunger has covered the fill slot in the sleeve (inside the pump), and the crank should be at exactly 26 degrees BTDC. Loosen IP to adjust. Loosen the three nuts holding the IP in place and rotate it toward the block to make the injection earlier or away from the block for later. Rotate engine two turns and verify correct timing, then tighten the nuts all the way, replace the valve and spring under the pressure valve holder, and re-start.

Make absolutely positive that the crank/cam timing is correct -- if you are off one tooth on the cam gear, the exhaust valve will hit the piston on each cylinder, making a terrible racket and resulting in very low power. It will also dent the pistons and eventually snap the cam towers. check by rotating the engine by hand -- any hard spots with clunks means something it hitting.

Peter