B7200 starting problems

[Orangefox40]

B7200 starting problems Solved

Hi all,
So I picked up a B7200HST about 6 mos. ago and have had a great time fixing her up. Her name is Betsy Bota and she's an "86" vintage with a FEL and 3PH Blade. She has always started although sometimes grudgingly. Recently I plowed the driveway and parked her outside overnight (for the first time) and the temp went down to about -13C. When I tried to start her the next day the temp was about -10C and she would not go. She had a magnetic oil pan heater attached and I covered her with tarps to keep the wind out. I Boosted her from my car so cranking was pretty good but this still did not help.
I have moved her inside (dead weight move) and today to temp was just around freezing. She had several heaters plus a battery boost and cranked quite fast but still she would not start. Initially I attributed the "no go" to the cold weather but now I'm not so sure. As I crank the engine smoke comes from of the exhaust, initially black then more grey. I tried shutting off the fuel cock at the filter to purg the engine of residual fuel as I had cranked the engine for some time. This also did little.
The only filter I have not yet changed is the fuel filter, apprehensive about introducing air into the fuel system. I have since learned how to purg the fuel system of air so will be changing the fuel fliter tomorrow. The glow plug indicator works well but unsure if the glow plugs themselves actually work. replacements are on the list.
Any insight as to why these engines may have difficulty starting would be greatly appreciated.
Regards,
Ron

 

[Pat Pending]

I have a B7200 as well and recently finished a minor rebuild of the engine. The first thing I'd suggest is to loosen the high pressure lines at the injectors and see if they bleed when you crank the engine (pull the decompression knob for that).

If so, I'd tighten it back up, crank some more without the decompression on and wait for fuel vapor to come out the exhaust. Then I would use the *tiniest* shot of ether in the intake. My engine will kick with only a slight hint of ether (without preheat) but any more than that will want to pre-ignite which does you no good. This will tell you whether or not your glow plugs are doing their job. ***disclaimer*** The use of ether mentioned here is for diagnostic purposes!

If you aren't getting fuel to the injectors, start at the filter and do systematic elimination.

 

[Orangefox40]

Re: B7200 starting problems Solved

Hi All,
Here is an update on my B7200 starting problem. I first changed the fuel filter, which was disgusting by the way. This is the only filter I had not changed as I new about airlock problems. The filter was not only really dirty and the bottom of the bowl was caked with sludge, but the top of the filter had worked it's work up and over the O-ring seal at the top of the filter element. I also found a pinhole in the fuel line from the tank to the fuel filter. Fix all this and now it's time to bleed the system. The B7200 has a self bleeding filter with a vent tube back to the fuel tank. Problem one solved. The B7200 also has a bleed needle valve on the fuel injection pumps with a vent line up to the top of the #1 injector. The manual shows a bleed screw/nut, but not so, this is a knurled thumb screw that turns about three turns out to bleed the injection pump. So thats it for bleed screws so you figure it should be good to go.......NOT SO. This only bleeds up to the injection pump. My airlock, yes this is why she would not start!!! My airlock was between the injection pump and the injectors proper. Three individual steel tubes connect the injection pump with each of the injectors. You have to loosen each injector nut to disconnect the tube and crank the engine to pump fuel through the tubes to bleed them and reconnect. The tubes are only 6 - 8 inches long and you would never think that air would get trapped there but it does so you have to remember to bleed all the way right up the to injectors or she'll never start. Also, After speaking to a diesel machanic and describing my symptoms he said light grey exhaust smoke usually means an airlock.
Happy Tractoring
Ron