Detroit won't start when cold????

The srs and and trs sensors are located on the left side of engine. One is located behind the aircompressor and the other is located below it.

 

This is what they look like.

 

If you havent changed the SRS TRS sensors it wouild be a good start. A lot of guy's keep spares in the truck it is not un-common to have them fail. When you remove them check for metal shavings.

 

Many times a TRS and SRS will set codes for to many missed signals. However, I've seen them fail where they do not set codes. I think they must just get weak, so cranking rpm isn't enough to get a signal, when you use either it fires and they work when the rpm gets above cranking.

I'm still not sure if it's your issue though. It's odd that it's fairly consistent, starts fine until it sits about 2 hours. The ones I had fail in that way didn't have to sit that long. It wont hurt to try swapping them though. Even if it's not your problem, they're good to keep in your truck becasue they do fail.

 

back check going bad are common on ser 60. had numerous drivers that I helped with this. my davco back check got a piece of foil stuck in it from me one time, but that did not affect starting. if the fuel in the dome can be seen then it is not causing your symptoms. cause the system is air tight. now if you take top collar off davo allowing air in, & the fuel drain back into tanks, then you need to see what is keeping your back check open. I think it is the -o- ring in the back check rear of the head. some leak down gradually like hard to start if truck is off for 24 hours, some leak real bad, like yours. it is not the davco. just look at the dome. is there fuel in it? if yes then leave the davco alone.

 

if you want to check the back check on davco, open top collar, drain fuel all the way out, then put new clean fuel in. if the back check is bad, you will not be able to fill up dome. it will run right back into your tank, faster than you can pour it in. however if you can refill & the fuel stays in the dome. your good.

 

If he needs starting fluid to get it too fire, then it runs fine, there is nothing wrong the TRS/SRS sensors. If there was it would never fire. Still sounds like a fuel issue.

 

Not So mine was bad and starting fluid would increase speed just enough to increase signal. Not sure its his problem but it is not un-common. Does sound like a leak down issue.

 

Have to agree with Rebel on this one. I have had 2 trucks that had bad timing sensors that had no codes but truck would only start with ether. Thought it was check valves to start with but after replacing issue was still there. Timing sensors fixed it.