That's right, 'cool'. If the temp outside gets below about 40 degrees, it will turn over, but not start.
If I plug it in, depending on how cold it actually is, for about 1/2 an hour, it will bust off with no problem.
This rules out an air leak in the fuel system.
I checked power to the air intake heater (ok), replaced air intake heater (old one got hot enough to burn me, but replaced anyway...wasted money).
If it were an injector, ip, etc., it wouldn't make any difference when I plug it in...right?
Is there some kind of solenoid or acctuator, etc. that could be causing the problem? Truck runs great and doesn't burn or make oil. Batteries are still strong and only about a year old and have tested ok.

Need some advise from all you experts on what to try next.

Thanks

 

Anybody? Is there something that I'm missin?

 

When it cranks, but doesn't start, do you get white smoke(raw fuel) out the exhaust? Put a volt meter on it while it cranks, & make sure the batt. voltage doesn't drop below 8-9 volts. If it does the computer is shuting off. Does it crank at a decent speed? You may have a bad starter that is dwawing too much amperage.

 

No white smoke.

 

That means no fuel delivery. Check the voltage while cranking. If it drops below 8-9 volts that is probably your problem. Got any codes? Lift pump, fuel filter all OK.

 

If that were an issue, would it matter that it starts fine in warmer weather?
How is the best way (location) to measure the voltage you are talking about?

 

I would check @ the battery terminals. Use some alligator clips & set the meter where you can see it when you crank it over. If it's good there try again on the starter post. Cold temps lower batt voltage, & increase the power required to spin the engine. The problem would probably be the starter drawing too much amperage just to spin itself. Also make sure you have good connections between the 2 batt's too. One will start it when it's easy, but thats why there are 2, for when it's hard. There could be a hundred things that could cause this. This is where I'd start.

 

sure appreciate it. I'll start there.