What does that mean?? Many and probably most DB2 pumps develop weak timing-advances by the time they've got 120,000 miles on them. By 185,000 they rarely work at all. It's the #1 wear problem in that pump. Even more true if fuel with low lube is used. That is the reason why the military started using the hard parts from the "arctic" kits. It's to make the advance last longer.it's definatly not worn out it only has 185k on it
It depends on what it's doing now. With a pump working correctly - moving it advances both the initial timing when starting AND the final timing advance when going down the road fast.geting ready to turn the fuel screw up on my 91 non turbo and wondering if it would be beneficial to twist the pump for advanced timming as well? if so how much? i was thinking i heard about two dimes width.
The timing is bascially the same as on a gas engine. The problem is how to interpret the specs.Can someone post the actual timing specs?
Injection timing AND ignition timing @ rpm
Diesel lag varies because of injection line length and injector opening pressure. Since line lengths and opening pressures varie engine to engine, so do the lag-times.The documented degree difference between injection & ignition VARIES from post to post (5-6-7 degrees lag)
The reason I'm asking again is I'm still trying to time my 6.5 DB2831-5088 setup.
Your specs look backwards to me. The Stanadyne DB, JDB, DC, DM, DB2, and CB pumps all advance more as RPMs increase. You have your's decreasing as RPMs rise and that makes no sense. If you read 4 degrees BTDC @ 650 RPM and 2 degrees ATDC @ 1300 RPM -that's saying your RPMs went up by 650 as your timing retarded by 6 degrees. That is inverse. Timing is supposed to advance, NOT retard as RPMs rise.
I checked out many 6.2s when new with a timing light and tend to set all of mine the same way. 8 degrees BTDC at hot idle and 22 degrees BTDC when hot at full advance/high RPMs. I suppose that translates loosely to 3 degrees BTDC hot-idle and 17 degrees BTDC at hot high RPMs. And note that I'm using engine degrees and engine RPMs. The pump runs half-speed so pump specs are 1/2 of engine specs. I.e. 8 degrees measure at the engine = 4 degrees measured at the pump.
When Stanadyne pumps are used in industrial equipment - and mounted outside on the side of the engine - they are timed by using a $10 plastic timing window with degrees on it. You bolt it to the side of the pump- run the engine - and check the timing advance easily with no special tools. Just an eyeball that works.
I just got done setting up a Stanadyne DB pump this morning on a John Deere diesel. It works like this:
At 400-600 pump RPM it advances 1 pump degree
At 900-1000 pump RPM it advances 4 pump degrees
At 1300 pump RPM it advances 7.5 pump degrees
That equals at the engine:
At 4800-1200 RPM it advances 2 degrees
At 1800-2000 RPM it advances 8 degrees
At 2600 RPM it advances 14 degrees
The 6.2 uses generally the same specs as most mechanically injected diesels do - as well as many gas engines.