I did the fountain test with the injectors and glow plugs in. I could do the test again with them removed but as it does not stumble under a load I think I will just run it as long as I will need it for the summer and fall. If the low compression and smoking on startup are still occurring I will tear it down this winter, get the front cover off and check the timing marks. That will give me a baseline for moving forward. Thank you for your help. Larry.
B7100 Piston Installation
- Thread starter Schmotown
- Start date
Hi Larry,
as far as I understand is the smoke at startup the problem, after that the tractor is running fine and has power.
The smoke is either oil or Diesel that got into the exhaust unburnt. You mentioned poor starting. This is what I would focus on. The glow plugs you changed already but I would ask you to measure the current into each of them when pre glowing. I had a faulty glow plug and this lead to the same symptoms what you are seeing, a lot of smoke at startup and then running fine. Low compression could be the cause of that too of course.
Wrt to the injection pump, without the injectors no pressure is building up and all you see is a small drop of Diesel, which is basically all a cylinder gets per ignition.
Kind regards,
Hugo
as far as I understand is the smoke at startup the problem, after that the tractor is running fine and has power.
The smoke is either oil or Diesel that got into the exhaust unburnt. You mentioned poor starting. This is what I would focus on. The glow plugs you changed already but I would ask you to measure the current into each of them when pre glowing. I had a faulty glow plug and this lead to the same symptoms what you are seeing, a lot of smoke at startup and then running fine. Low compression could be the cause of that too of course.
Wrt to the injection pump, without the injectors no pressure is building up and all you see is a small drop of Diesel, which is basically all a cylinder gets per ignition.
Kind regards,
Hugo
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Just for fun and giggles, I investigated my B7100 (1994 version) exhaust manifold temperatures with a TIC. I set it to °F for consistency with your readings and turned on high, low and centre spot readings. After about 20 minutes of running:
180°F at #1, 220°F at #3. 40°F difference. Ambient temp 75°F.
I don't think you have anything to worry about. Ok, it's sample size of two, but thus far 100% of all D750 engines investigated show notably lower EGT at the #1 cylinder. <lol>
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