Volvo Penta MD2020 will not start after head service

After spending quite a bit of money and effort extracting the cylinder head from my MD2020 and sending it off for service (working thru a local diesel shop) and putting it all back together I am unable to start the engine. I had the local diesel mechanic out for a few hours and he to was unable to start the engine.

The original problem was that rather suddenly I lost power in the engine and noticed a black line (soot I think) in the exhaust. After another half hour of running it died even in idle, and I was unable to start. The mechanics around here all thought it was a head/valve problem with valve stem seal leakage. So I did the cylinder head extraction and work.

Now it has new valves, new injector nozzles, and lots of new little things and still won't start. Now the local gurus think it is injector timing. Some suggest I buy a new engine. Help! Is it really that hard to fix this thing? The local mechanic thinks it will be thousands of dollars more.

The first thing to check if the quality of your fuel. Try to run the engine from a different container of fresh fuel.
The orginial black soot may have been carbon/burnt oil. This may be a sign of oil leaking up past the pistons. When the head was removed, did the cylinder walls look scored? When you try to start it, are you getting blowby at the breather? If the head was serviced properly, and the cylinders are worn, the compression will escape to the crankcase. A compression or cylinder leak down test will quickly determine the condition.
Also, are you getting fuel to the injectors? The fuel timing was not tampered with if the head was removed without touching the injector pump.
If the engine is getting fuel at the proper time with compression, it should fire!
Good luck.

Have you bleed the entire fuel system after you install the head ? Have to get ALL the air out, or it will never crank !

glen_adolph said:

The first thing to check if the quality of your fuel. Try to run the engine from a different container of fresh fuel.
The orginial black soot may have been carbon/burnt oil. This may be a sign of oil leaking up past the pistons. When the head was removed, did the cylinder walls look scored? When you try to start it, are you getting blowby at the breather? If the head was serviced properly, and the cylinders are worn, the compression will escape to the crankcase. A compression or cylinder leak down test will quickly determine the condition.
Also, are you getting fuel to the injectors? The fuel timing was not tampered with if the head was removed without touching the injector pump.
If the engine is getting fuel at the proper time with compression, it should fire!
Good luck.

Click to expand...

The cylinder walls were not scored, but they were a bit sooty. There appeared to be compression. We pulled the glow plugs and pumped some oil in and watch it fly out as the engine was cranked. Compression tests at the blow plugs indicated decent compression. Our thinking now is that the timing is off...it is getting fuel, and the injectors appear to be working fine.

Yes the entire fuel system was bled...repeatedly. It was new fuel, and the fuel filter and fuel prefilter were all changed. After hours of bleeding fuel was everywhere and it all looked good.

Is the sea water pump hooked up to the front of the injector pump? If so, it may be too tight and interfering with the timing advance.
Also you may verify that the timing marks are correct by putting the #1 cylinder at TDC with a straw or similar rod in the injector hole. Then look at the flywheel to verify. Then look at the timing mark on the injector pump. It is rare, but I have seen timing marks off.