Sycamore, Sunday Dec 23rd?

Only thing I could think of is maybe my fuel pump is going out and I'm not getting fuel pressure but that wouldn't necessarily explain why it won't start in the morning but does in the afternoon

 

Do you smell fuel when you've tried cranking for a while? Have you checked your plugs for fouling?

Cold start problems are generally battery or fuel related. If your battery checks out, try confirming the output from your coolant temp sensor.

From messing with another car I have I know that the fuel requirements for starting when really cold are very different from when it is marginally cold. If the numbers are off by as little 10% the car won't start. This car to which I'm referring uses E85, which is a real bear to start cold anyway, but it's a place to start. I would imagine checking the output of the coolant sensor wouldn't only take a few minutes with a volt meter.

Good luck.

 

No fuel smell, I haven't checked the plugs but will in the morning. The batteries are good, both yellow tops are in the cab and not the engine bay. Just find it odd since I never had any issues in Colorado with the colder temps which were definitely colder than here.

 

Tried it again this morning and still wont start. I've tried the other key, even disconnecting the battery and switching the batteries back on. Will wait until later this morning when it warms up

 

Of course, I just tried starting the truck and it fired up with no issue on the first try, wtf? lol

 

Thats so weird.

 

Paden didn't you take pics?

 

12pk on me for anyone that can solve this shit, its driving me fucking crazy not knowing why lol

 

Check your t-stat. You have a blower right. I'm assuming you may not have the factory t-stat

 

Solid point.. also what EMS are you running? Possible calibration issue?

 

yeah, but they're pretty much the same as yours lol

 

Higher quality though.

 

I'm not too familiar with the 4.0. Does the thermostat output the coolant temp to the ECM? Normally, the thermostat opens at a fixed temperature and does not monitor the entire temp range and the coolant temp sensor monitors the entire temp range.