Hey troops,
I really need some help from the experts. I'm an engineer and have run through every permutation I can think of to fix this rig. Now it's driving me crazy.
I have been slowly restoring my 1978 LHD HJ45 with the 12Vdc H Diesel motor in it over the past 3 years. Unknown mileage, import from Columbia. As you can see from the pics, I have a lot of time and $$ invested in making it look and run great again.
I've replaced the injectors and glow plugs and both of these items are working great now. I've adjusted the valves per the manual with the engine warm. It starts right up after a 20 sec morning glow but smokes black a lot, runs very rough and does not want to accelerate without loading up really bad and smoking black even more. If I drive it around and force it to accellerate while all black smoke pours out, eventually it clears up some and the smoke decreases substantially except at full throttle. It does not have much power though. I live at 6800ft and tried adjusting the HAC for max fuel just before smoking too bad and it helps, but creates even less power. I have installed a Wilson switch and am using 10V glow plugs so I can do a manual glow whenever I want. If I glow after start, it helps clear up the idle but when I let off it loads back up again. Engine shakes quite a bit.
Earlier, I replaced the pneumatic governor diaphragm and tested that it held vacuum. I've bled the fuel system countless times per the manual, new air filter, new oil and filter, new fuel filter, fuel lines and cleaned fuel pump screen along with new coolant, hoses, thermostat and cap. New valve cover gasket, oil cap, new intake, venturi and exhaust gaskets. I used all OEM part$$.
I pulled the radiator cap off when I started it yesterday and sure enough, I had bubbly and frothy new coolant. So, I figure head gasket must be shot. Before pulling the head and going through all those motions, I did a compression test this AM via a diesel compression tester through the glow plug holes.
Here are my conditions of the test. Cold engine(likely would be higher warm but just wanted a baseline), 70 degF air temp. Here are the results, tested twice and averaged results(they were within 2 psi)
Cyl - first fill - final fill
1 - 179 - 330
2 - 162 - 318
3 - 160 - 302
4 - 163 - 300
5 - 170 - 318
6 - 180 - 320
The H service manual says 421 PSI new, 284 PSI limit and 28 PSI difference. Clearly the motor is worn and the overall numbers are low, but still within spec. The difference of 30 PSI between One and Four concerns me. I was honestly expecting to see much worse since the coolant is so bubbly.
With these compression numbers, what should I check next? I do not have a leakdown tester unfortunately. I'm really frustrated and do not know what to try next or where the blowby into the coolant could be coming from.
The oil did not have coolant in it and the coolant did not have oil in it so they are not mixing.
I know putting $$ into the H is not ideal but that is what I have and 2H motors don't exactly grow on trees in the states.
Help please, suggestions/tips greatly appreciated.
Thanks,
Mark
I really need some help from the experts. I'm an engineer and have run through every permutation I can think of to fix this rig. Now it's driving me crazy.
I have been slowly restoring my 1978 LHD HJ45 with the 12Vdc H Diesel motor in it over the past 3 years. Unknown mileage, import from Columbia. As you can see from the pics, I have a lot of time and $$ invested in making it look and run great again.
I've replaced the injectors and glow plugs and both of these items are working great now. I've adjusted the valves per the manual with the engine warm. It starts right up after a 20 sec morning glow but smokes black a lot, runs very rough and does not want to accelerate without loading up really bad and smoking black even more. If I drive it around and force it to accellerate while all black smoke pours out, eventually it clears up some and the smoke decreases substantially except at full throttle. It does not have much power though. I live at 6800ft and tried adjusting the HAC for max fuel just before smoking too bad and it helps, but creates even less power. I have installed a Wilson switch and am using 10V glow plugs so I can do a manual glow whenever I want. If I glow after start, it helps clear up the idle but when I let off it loads back up again. Engine shakes quite a bit.
Earlier, I replaced the pneumatic governor diaphragm and tested that it held vacuum. I've bled the fuel system countless times per the manual, new air filter, new oil and filter, new fuel filter, fuel lines and cleaned fuel pump screen along with new coolant, hoses, thermostat and cap. New valve cover gasket, oil cap, new intake, venturi and exhaust gaskets. I used all OEM part$$.
I pulled the radiator cap off when I started it yesterday and sure enough, I had bubbly and frothy new coolant. So, I figure head gasket must be shot. Before pulling the head and going through all those motions, I did a compression test this AM via a diesel compression tester through the glow plug holes.
Here are my conditions of the test. Cold engine(likely would be higher warm but just wanted a baseline), 70 degF air temp. Here are the results, tested twice and averaged results(they were within 2 psi)
Cyl - first fill - final fill
1 - 179 - 330
2 - 162 - 318
3 - 160 - 302
4 - 163 - 300
5 - 170 - 318
6 - 180 - 320
The H service manual says 421 PSI new, 284 PSI limit and 28 PSI difference. Clearly the motor is worn and the overall numbers are low, but still within spec. The difference of 30 PSI between One and Four concerns me. I was honestly expecting to see much worse since the coolant is so bubbly.
With these compression numbers, what should I check next? I do not have a leakdown tester unfortunately. I'm really frustrated and do not know what to try next or where the blowby into the coolant could be coming from.
The oil did not have coolant in it and the coolant did not have oil in it so they are not mixing.
I know putting $$ into the H is not ideal but that is what I have and 2H motors don't exactly grow on trees in the states.
Help please, suggestions/tips greatly appreciated.
Thanks,
Mark
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