Hello,

I have a w124 with a 603 engine. It has recently lost a bunch of power, and feels like a fuel delivery problem. (bursts of power) My mechanic found the #6 cylinder was dead, so we decided to to a compression test. #6 was at 310psi.

So we thought it would be a injector, replaced that too, and the engine is still running rough. We put an alternate tank (gatorade bottle with diesel, with a supply and return near the water seperator) the car ran better but still not great. It is significant to mention I run vegetable oil in it, and have been for about 2 years 35000 miles.

Mechanic thinks may be injection pump, by why only cylinder #6? Any ideas?

Thanks,

Hoover