800 Case Injection Pump timing

rickdude · Jan 31, 2023

Ive got an 800 Case COM with the American Bosch PSB Rotary injection pump. I have specs in my manuals for 500 600 and 900 tractors but I havent found anything specific for the 800. Ive set mine at 32 degrees BTDC on the crank pulley scale but Im not 100% sure this is correct. Ive had it running but seemed hard starting to me, although it hasnt run in about 15 years so maybe just needed to blow the cobwebs out.
Thanks
Richard

casecollectorsc · Feb 1, 2023

Manual says 33 degrees and 1850-2000 psi for injector nozzle opening.

rickdude · Feb 1, 2023

Great, thanks Im pretty close at 32, just a little tweak from here. The manuals Ive found cover many of the other models but nothing on the 800 specifically

mEl · Feb 1, 2023

(quoted from post at 12:10:14 02/01/23) Great, thanks Im pretty close at 32, just a little tweak from here. The manuals Ive found cover many of the other models but nothing on the 800 specifically

You can change it that Degree but you will not notice the difference and the further from TDC you time it the harder it will start, I have installed turbo kits on 830s and to get power you needed 35 degrees but they started noticeably harder cold. Combustion chamber temp is highest at TDC. When I was employed back in the 70s, 580C backhoes came out and were harder to start because of Govt emissions crap and Case sent kits to us to change timing from 8 degrees starting timing to 0 degrees.

rickdude · Feb 3, 2023

Thats good to know with the relationship between timing and hard starting. I was wondering if its a sign of low compression that its not igniting the
fuel in the cylinder. It puts up plenty of smoke but just doesnt quite fire without a whiff of ether, then once it fires I need to repeat with a light shot
every few seconds until it fires on its own, maybe 10 seconds worth. Would clogged up injectors cause this? . The fuel system was really dirty when I
started working on this tractor. It also has a manual primer on the dash that is supposed to allow you to add a shot of fuel into the intake when
starting, I need to pull it apart and figure out how to get it working, but I havent found any reference to it in the manuals

mEl · Feb 3, 2023

Injectors with a ragged spray pattern certainly would hurt starting and most injectors this old will certainly not be as new, Low battery amperage under cranking load, bad or to small cables and poor starter condition are other reasons for hard starting. Diesels need to turn fast in cold weather to start. Also, if there has been head work done ever and the valves and seats were ground and out of protrusion spec that really hurts.

800 Case Injection Pump timing

rickdude

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mEl

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