4020 diesel hard starting

dmk1957

Member
I would like to get my 4020 functional again but I don't have much experience working with diesels. The tractor generally will not start without assistance from the block heater or ether (which I generally avoid) unless the ambient temperature is approaching 80 degrees. It's a 1970 model, with a M&W turbo (installed early 1980's and I don't think they turned up the fuel). The engine has never been rebuilt and probably has 9-10K hours (hourmeter was replaced some time ago). The tractor runs fine at all engine speeds once started. It only is used for light work on a blade and brush cutter, so I can't comment on absolute power level. It has a Roosa Master pump model CBC-633--244L. The tractor has smoked constantly since new. I'm told this is a characteristic of that particular pump.

Other observations: One time I started it, let it run a few minutes, then shut it down. I tried to start it a few minutes later, and it refused to start, which made no sense to me as it had not been shut down long enough to cool off. A shot of either (ugh) got it going. Also, it is not consistent - some times it will start at a given temperature without help from the block heater, other times it will not.

My first thought was that with the advanced age and hours, compression is bad and that is the main problem here. But the other things I have noticed suggest that there might be fueling issues.

Advice? Thanks.
 
Most times hard starting is the result of lower compression.If it still has the short pump there are some places that can rebuild them but taller pump is usually better.9/10 hours with a turbo suggests it might be tired. The extra smoke with a turbo means fuel is not getting burned.Make sure if you put new S&P use the best ones as there is a difference and Tim S. might add which ones He likes best.
 
Your biggest problem is the inj. pump. Believe me they are no good . You need to update to the later pump and lines . And yes with that many hours and a turbo she's just tired .
 
Have the injectors pop tested, with this many hours on them they are bound not to atomize as the should and cause hard starting.
The injection pump can also have issues but i would focus on the injectors first.
Also it is worth it to do a compression test when the injectors are out and it won't hurt to check the check the IP timing.
 

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