This is my first cummins and I think I have gummed up my injectors but trying to use biodiesel when it was to cold. https://www.dieseltruckresource.com/...ewthread&f=93# I'v pulled the injectors and found a black coating on them now Im wondering what I need to do to the cylinders and all the cleaning options I might have.
any suggestions would be great.

 

First thing. Change the fuel filter. Assuming you haven't damaged anything else and your injectors aren't plugged up with gunk it should be OK.

B100 will disolve all the collected gunk in the tank and plug the fuel filter. The other stuff is a puzzle to me. After you take off hte filter, fill it with clean fuel then screw it back on. Then crack the vent which looks like an extra hex head screw on the output banjo of the fuel line going to the inj pump. Then work the pump lever on the fuel pump to purge air from the top of the fuel filter.

If the inj were starved for fuel there's air in the lines which must be bled out. Just have somebody crank it and crack the lines 1 at a time until fuel sprays out. Be careful and don't let the fuel hit your fingers because the high pressure will cut.

People sometimes start with B2 then B5, B10, B20... until they're up to B100. B100 will also attack the seals and hoses in your pre-64 fuel system so this might be a problem. I'm not sure how much an upgraded Inj pump will cost but it ain't cheap.

Edwin

 

Also, if you're not running B100 you shouldn't have any more problem with it than regular diesel #1 blend. Just dump in a double dose of Power Service white bottle and it should prevent gelling and will clean your injectors also.

Edwin

 

By "black coating" do you mean the injectors are sooty, or is there some kind of shiny varnish on there? Diesel injectors always look sooty when you pull them, nature of the beast.

 

I believe that it was carbon caked on the injectors which I scraped off. I put the injectors back in and it started first time but then died. could it be that when the engine warms up the injectors can't handle the increased pressure with out a proper cleaning?

 

Nope, it sounds like your injectors are OK. Sounds like you are not getting a good fuel supply to the pump. Do what Edwin suggests - change the filter and bleed the system. By pulling the injectors you have introduced a lot of air into the high pressure system than needs to be purged out.