03 won't start cold

[MZuba]

My 03 won't start after it sits overnight when its cold (20 degrees or lower) its happened twice. I replaced the intake heater, and still no good, I posted in the 911 forum, but then thought to put it here. The relays cycle, the heater did heat up, I put the new one in yesterday, this morning no go, it was 16 degrees this morning when I tried it. I plugged in the block heater for less than an hour and it fired right up. My local truck shop put it on a computer when it did it the first time, ran diagnostics and the computer said there was nothing wrong and all things functioned normally, there is no check engine light or codes. Does anyone know if theres a fuel heater on the 03s? I would appreciate any help. This truck has never had any cold starting problems before, allways started even below 0 without the block heater. Thanks!

 

[CumminsBu]

The fuel may have gelled up, but depend how many mile or hours your truck has it may be time for new injectors. Yes the 03 have a fuel heat on the side of the fuel filter canister.

 

[MZuba]

Thanks for your reply, truck has about 115k on it, it runs great all around, just this one temperature problem, It doesn't smole at all, how would I be able to tell if the injectors are going? Thanks

 

[ScottHunter]

I have a 03 ho auto 4x4 129k hade the same problem in oct 08 and again 09. I replaced 6 inj and fuel tubes in nov 09 after a cummins cert shop spent 8 hrs testing the inj fuel returns and presure ind and as a group and my grid heater. Thy told me acording to cummings specs the inj were not the problem. I had them replaced and in 10f it starts like its 80f outside.

 

[MZuba]

I was just messing around with it, and took a look at the fuel heater, i took the cover off it, looks to me like one side of it is some kind of thermocouple, or temp semnsor, there is power going to the bottom side of it, but nothing coming from the top of it, ( i figured it was at a temp to high to close the circuit, so i actually cooled it off by holdong ice to the face of it , and it never let power through). Now I am asuming this is the function of that item, anyone else know if it is?

 

[rbattelle]

I don't believe what you were looking at is a thermocouple - it's a resistance heating element. The ECM commands the heater on when the ambient temperature is below 45°F. Power is 300 watt.

Power is sent through a fuel heater relay, so you'll want to check that (fuse box). Use an ohm-meter to test the heater itself - when cold, the resistance should be 0. 3-0. 45 ohm.

Are your batteries good? I can't help but wonder if you've got a high pressure fuel issue preventing the system from fully pressurizing during startup. The problem could be aggravated by weak batteries that don't allow the starter to crank the engine fast enough, which would explain why the problem manifests only during cold weather.

Ryan

 

[MZuba]

Ok so far I have tried all of the easy suggestions, new heater, new batteries, etc, and still nothing any more ideas, is there a way to check the injectors to see if its the problem, I did notice, no matter how long it cranks, i get no smoke from the exhaust at all so I am figuring definATLY a fuel problem

Thanks

 

[MZuba]

No matter how long I crank the engine, it won't start when the temp is low, (less than 30), I have to plug in the block heater for 30-45 min and it fires right up.

 

[MYeary]

mine did the same thing & one of the two relays was not working, still works with one relay but not enough to start in cold temps. (70. 00 a set at the dealer)