my buddy has am 03 2500 5.9L CTD
he had trouble starting it in cold weather (5 C), so he got the fuel heater replaced, worked fin for a few days and now he has the same problem.
It will start if he sprays engine starter (ether) in his air intake.
oh and he leaves it plugged in over night
hes taking it back to the mechanic next week but i was just wondering what you guys think
thanks

 

Could be the pressure relief on the rail, or something amiss on the injection pump. The FCA (Fuel Control Actuator) can cause this also, it sounds like the pump or the reliefs are not allowing enough pressure to build at a slow crank. Also are his batteries up to par?

 

Maybe the relay for the glow plugs is bad? Also, if the relay sticks it will eventually burn out the glow plugs.
Does it smoke or have rough starting issue's? if so, the glowplugs could be the problem. Either burned out or heavily sooted.
Also, is he running summer blend or winter blend? Summer blend has a clouding point of 40*F or 5*C where it will form wax crysteals in the water/fuel separator thus blocking fuel delivery. The heater being plugged in likely eliminates this.
I'd have him throw in an additive in the tank and see if it starts easier. if not, then bring it to the mechanic because he could be throwing his money away with a mechanic telling him nothing is wrong and/or having the mechanic say this/that is wrong and then spend all kinds of money for no good reason.

 

Disregard most of this post. Cummins DO NOT HAVE GLOW PLUGS, they have an intake heater grid. STOP SPRAYING ETHER INTO IT. The heater grid is in the intake. If the ether ignites, BOOM GOES THE INTAKE MANIFOLD. The heater being plugged in only heats the coolant, not the fuel.

 

 

ok so what should i have him check, voltage at the heater grid?

 

deff stop spraying starter crap in the intake. like brian said. boom there goes ur intake. not a good thing todo. it even says not to use the stuff rite on the intake cover. just be careful.