soot on plugs

[Andylad13]

could soot build up on the glow plugs hinder there heating ability?? my truck has been not starting up to potential latly, and when i plug it in she fires right up, so i've narrowed it down to a potential plug related problem.

i tested them all, not ohmed them, but with a test light, and they work. but when i pulled the #1 one out, it was like sliding it out of a sleeve of soot.

other info...i am running lucus injector cleaner with every tank at the moment.

 

[Diesel JD]

Some of that is going to be normal I would guess. The real question is what is the cause of the soot, do you have excessive blowby, too high EGTs? Are the glow plugs marginal? With a test light if they can complete a circuit they will test good, you might check them with an ohm-meter and see what values you get. If you get one that is not an open but still has resistance above 1 or 2 ohms it might cut your cycling time down. Maybe you could also post a pic of one of the glow plugs in question so we can see how bad they are, cause as I say they are going to have some soot on them in an old smoky engine, but how much is too much? I really don't know.

 

[Andylad13]

ill ohm them. what is the best way to do that, where do i put the ends of the multimeter?

 

[Diesel JD]

Put the red lead to the bullet and the black lead to the threads. Set your ohms to the 20 ohm setting. You want them to be less than 2 ohms. If they test good you could maybe clean the soot off of them with some fresh diesel or biodiesel and then dry them off and put them back in, see if it helps...

 

[Andylad13]

thanks buddy.