2003 won't start when cold

[JeffL]

Hey everyone,

My 03 has been taking a little longer to fire when starting the past couple months, and now in the morning it's not starting. I plug in for an hour or so and it finally starts and runs fine, no stumbling, smoke or anything. Once warmed up it restarts fine. Grid heater is functioning properly, fuel pump is running, just won't start if it's below 40 or so. After researching it a bit, it seems like it may be the injectors, but I just wanted to check in here before taking the plunge to change. Anyone have any other ideas, before I swap the injectors? Thanks



2003 3500 QC SRW 4x4 6spd

 

[goodguys75]

if it is the injectors it would be giving you a lot of problems... especially if you say you have no issues once it fires up... but the experts will soon help ya ...

 

[goodguys75]

are the batteries still going strong, original???

 

[JeffL]

Batteries are a year old and seem to be strong. They are a cranking it over a little slower than normal on these cold mornings, but no where near dead. Maybe I should put a charger on tomorrow morning for a bit and see if that makes a difference? Thanks

 

[goodguys75]

seems like bad or weak batteries, cause issues with these trucks... . you might want to post how many miles on truck and any modifications... for anyone who can respond to your issue. . they may need that info... some of these Santa helpers are picky..... :-laf

 

[JeffL]

There are a 130,000 miles, smarty s-06, afe intake. Seems as though from what I've read, that the injectors may be sticking open allowing the fuel to drain back to the tank. When cold there is not enough fuel pressure to start, but once warmed up, the injector expands allowing fuel pressure, and it fires. Make sense??? Thanks

 

[BDaugherty]

You need to be able to read rail pressure to make an accurate diagnosis. My '03 did the same thing. When it was cold soaked below 60 degrees, the injectors were bypassing too much fuel and it couldn't build rail pressure. My truck takes about 900 psi for the computer to turn the injectors on. When it was cold, I could crank it until the brand new batteries were dead and it wouldn't get over 700 psi. Now that I have a complete new set of injectors, it build rail pressure so quickly that it's hard to tell what pressure it starts at. Bottom line is that you may need a set or you may only need 1. There are multiple ways to go about finding out, but the cheapest would be a rail psi gauge and rail cap. You can hook up the gauge (or scan tool) and turn it over to see what the rail psi is. Then you can cap off 1 injector at a time and try to start it. If you have a single bad injector, it will start when you can that one off. You can also pull them all out and send them to be tested.

 

[Slow Six]

My experience with my 03 when it acted like yours was I needed injectors. I also changed the crossover tubes at the same time, a step the may not have been necessary but is easy to do at the same time. It is not so much that the fuel drains back as the injector(s) leak causing low pressure on the rail. The computer has to see a minimum rail pressure before it will allow the injectors to fire. This can be compounded by slow cranking. The first time I had this problem I put in new batteries and I thought problem solved but it returned in a couple of weeks. New injectors and tubes resulted in good starting until I had to do it again. The hard start can be inconsistent and some times no start. After the second set plus a transmission & rear end the "chip" came out. I feel that the injectors did not like chips, especially ones that increase rail pressure. There were a lot of threads on this topic a few years ago and if you can do a search there will be a pile of info on this topic.

 

[JeffL]

Thanks. I have an extra set of stock injectors that we're good, so I will go ahead and put those in. I will update after the change. Thanks again.

 

[JJPage]

I would simply re-torque the cross tubes(37/39 ft lbs) before I did anything else. The tubes being loose will pass fuel when cold, when heat soaked the tolerance is less and you are running fine. You will need a good short handled torque wrench, a 19mm and a 24mm crows foot, remove the intake horn and all the injector lines, now re-torque and put your truck back together. It's free if you are the least bit mechanically inclined, and may solve your issues.

 

[JeffL]

I will go ahead and give that a try today. Thanks, that would be much easier than swapping injectors. I'll keep you posted.

 

[SWithrow]

Thanks. I have an extra set of stock injectors that we're good, so I will go ahead and put those in. I will update after the change. Thanks again.

Did the extra set come out of your truck? If so I would re-check the crossover tubes before tearing it apart.

 

[JeffL]

No, the set is in a spare motor I have. It was the original motor to the truck, and the injectors were good when the engine was pulled. If I do go ahead and pull the injectors to swap, do I need to get new o-rings or gaskets for anything? Thanks again.

 

[EthanWhite]

I'm having the same issue with my 2003. I'm in the midst of troubleshooting it now. Let me know what ya'll find...

 

[JeffL]

Ian, I lucked out and added some power service and changed the fuel filter. All is well, for now. I recommend try this first, before doing anything with the injectors. Let me know how you make out. Goodluck.
Jeff

 

[goodguys75]

Ian, I lucked out and added some power service and changed the fuel filter. All is well, for now. I recommend try this first, before doing anything with the injectors. Let me know how you make out. Goodluck.
Jeff

that's what i did when i had problems. . i just used diesel kleen from wallmart... . never had an issue again... . over 1 yr... . but i always change fuel filter every 10,000 miles... for sure... ... must have been a dirty injector

 

[JDerbedrossian]

My truck has done this the last couple of days (34*) in the morning so I just leave the key on and let the fuel pump run a few second longer and it fires right up. Maybe theirs more to it ?