Author Topic: Injection Pump timing verification alternate method.  (Read 2513 times)

Tyler S

  • Associate Member
  • Platinum
  • ******
  • USA, CA, Encinitas
  • Posts: 1613
Injection Pump timing verification alternate method.
« on: January 25, 2016, 08:05:28 »
Verifying Injection Pump timing using pump piston position.
     "Ja18" and "mrfatboy" both have written excellent threads about using the position of the injection pump pistons to verify correct or incorrect pump timing. That thread here http://www.sl113.org/forums/index.php?topic=16056.msg168739#msg168739
This method is similar in that it too uses piston position but without removing the injector lines, fittings, and check valves. It can be done with just a stubby flathead screwdriver and a 27mm ratchet to turn the crankshaft.

Set engine to 20 degrees AFTER top dead center compression stroke on cyl #1
Verify engine compression stroke by removing oil cap and verifying #1 camshaft lobes are pointing up. See "CamLobesUp" Below
Remove 6 injection pump access cover screws and cover. See "AccessCover" Below. Some oil will leak so be prepared. This should only be done on a newer rebuild with a soft gasket so it can be re-used.
Verify #4 injector pump cam follower oil weep hole is almost completely visible. 3rd follower from the right in "20degATDC" below.
Moving the crankshaft 5 degrees below or above the 20 degree ATDC should result in no movement of the follower.
If there is movement the IP timing is slightly off.
If IP is timed 180 degrees out then it will look like the last picture below. See "180-Out" below.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

catjim813

  • Guest
Re: Injection Pump timing verification alternate method.
« Reply #1 on: January 26, 2016, 02:19:22 »
Tyler, once I get my fuel pump issue sorted out I will use your notes to verify if I placed my injection pump on correctly.  Thank you for posting.

Tyler S

  • Associate Member
  • Platinum
  • ******
  • USA, CA, Encinitas
  • Posts: 1613
Re: Injection Pump timing verification alternate method.
« Reply #2 on: January 26, 2016, 19:24:10 »
One thing I forgot to mention is you may want to remove the fuel return line from the IP. It will give you a lot more room to work but isn't necessary. I removed mine for good pictures.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)