MF 65, AD4-203 Cylinder black internally

Knivens894

New User
I have a 1962 MF-65 with Perkins AD4-203 direct injection diesel engine which was just completely overhauled.
When trying to start it, it turns over about 10 times then the engine locks. At this point it is very hard to
turn even with a wrench, so I pulled the head for inspection. I found the number 2 cylinder completely black
with soot while the others are clean. During the overhaul all injectors were replaced with new, as were the
pistons, sleeves and rings. I tested the valves and they are all sealing properly. I suspect a hydraulic lock
caused by a defective (leaking) injector on the number two cylinder. Before I button it back up, I would like to
know if anyone else has had such a problem, and if so, am I on the right track for the repair?
 
If you bought the injectors local I'd take the one back, if they came from an injector shop have them test it (or if you got it from a parts dealer have an injector shop test the suspect injector).
 
PT: All were purchased from Yesterday's Tractor. I have ordered a replacement and am awaiting its arrival. Do you believe I am on the right track? Could anything else cause this condition? If so, what?
 
About the only other thing I think it could be is the injector pump has some kind of problem. If you didn't have the injector pump tested it probably wouldn't hurt to have it tested.
 
I'd make sure the injectors have the correct tips in them too. AD152 and 203 engines have the bodies turned 90 degrees as compared to other Perkins engines. If the tips are the wrong spray angle engine damage is possible.
 
Today I took the injector to the test shop. They said it was good and met new specs. Turning the engine by hand, it still has a lock spot, so off with the engine and back to the machine shop. It appears no oil is getting to the bearings. The injection shop said there was no timing variable for the injection pump, so I was looking in the wrong place. Turning the engine by hand, it still had a lock spot with the head off and the cam out. Seems the machine shop has a problem with bearings and oil delivery. Even at cranking speeds it showed 80 psi, so some ports must be blocked somewhere. I am giving it back to them to figure out.
 
As much trouble as I have had trying to start this engine, I would have saved a lot of time and money doing it
myself. Obviously something is not getting oil on the crankshaft or in the cylinders
 
I took both the suspect injector and the injector pump and had them tested. They tested good, so I took the
engine back to the machine shop. They found diesel fuel in the oil. Please keep in mind this engine has not run
since it was completely overhauled. The injection test shop told me this injection system could not be installed
out of time if the gears were properly timed and the drive pin was in the machined slot. There is no timing
adjustment internal to this CAV injector pump. They said the snap ring could be moved in the pump, but if the
exterior markings were followed it should have been running correctly. I plan next to test the transfer pump for
leaks to rule it out as the cause of the diesel in the oil problem. My suspicion is the machine shop broke some
rings installing the new pistons in the new cylinder sleeves and blow by while trying to crank it put the diesel
into the crankcase. My suspicion is based upon excessive blow-by noted during attempted cranking.
 
Fuel shop is correct, CAV DPA pumps can't be assembled out of time. Only thing that can happen is if the cam ring is installed wrong, but that will show up on the test stand during calibration. Snap ring is not really an issue as some of the latest specs don't even have a letter spec anymore to set it to. Only way pump to engine timing can be off is if gears are installed wrong, or the pump installed wrong which will push the gear locating pin out of place, have seen that done before too.
 
Is it possible to break the rings on a newly overhauled cold engine with a shot of starter fluid? Has anyone had the experience to accurately comment on this issue? The engine HAS NEVER RUN and the engine oil had diesel in the crankcase on tear down.

The transfer pump has been checked for leaks, with none found. The CAV has been checked for a front seal leak and none was found. The injectors have been tested and all meet new specs. I contend the rings were broken on install, therefore the engine would not make the required compression and blew the diesel by the pistons. The machine shop says it is my fault because I hit it with a shot of starter fluid labeled for use with diesel engines trying to make it run. I need a knowledgeable unbiased opinion because I want to be fair in all my dealings.
 
I think that the machine shop broke them when they put them in. After the injectors were bleed it would have started the first time you tried to start it with no problem. Starting fluid is more likely to cause piston damage (the piston skirts mostly) than ring damage from what I've seen from too much starting fluid being used.
 
The machine shop says I broke the rings and crushed the pistons with ether while trying to start it. I talked with a man who does nothing but build diesel engines and has been doing it more than 35 years. When I told him what the machine shop said and answered some of his questions, he said the cylinders with adequate compression at tear down would have been black because they had been trying to run. The ones that were still clean aluminum had never fired because they never had adequate compression. He suspects the rings were broken during installation, scored the new sleeves enough during all my starting attempts to lock the engine and crush the piston lands. Long story short, the engine has been overhauled again with all new sleeves, pistons, rings and bearings. We will see if the second time around is any better. I will not use that machine shop again ever. They may do good machining work, but engine builders, they are not.
 

I am pleased to report the second overhaul was a success. It cranked on the first starter engagement yesterday and purrs like it should. I believe, like PTfarmer, the rings were broken during the first overhaul. It never had the compression to run. The broken rings scored the sleeves, broke the piston lands and locked up the engine. I learned during this process: black is the normal color for a running cylinder. After an engine overhaul, (and the engine was running when it was removed for overhaul), the engine should crank right up. If it will not crank with some or all pistons remaining bright aluminum, it is because those pistons are not producing the compression to fire that cylinder, (or the cylinder does not have fuel). Pulling fuel injectors to check for fuel delivery to each cylinder is a simple exercise. The lack of compression pushed the diesel fuel by the pistons and into the oil pan. If I ever have a problem cranking a newly overhauled diesel engine again, I will first check the oil for the smell of diesel fuel, and if none is present, I will find or make some way to do a compression check. I knew every cylinder had fuel on the first overhaul cranking attempt because I bled to the system completely before trying to crank it. I ruined two good starters and incurred a lot of expense and delays in eliminating everything else before I split the tractor and removed the engine the second time.
 

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