Weather Temp Swings Cause Engine Problems?

[Tom Stenzel]

I did some Google-fu on this one and came up empty. Some people have tracked down long cranking times on the Pentastar 3.6 to camshaft sensors but their starting problem was consistent in all temperatures.

Couple things come to mind that no one else mentioned, one is an injector that's leaking. When you start you would have 1 flooded cylinder and 5 starved ones.

The other off the wall thought is winter-summer fuel. Could you be running winter gas that's causing a vapor problem when it gets warm? Possibly a different brand of fuel might make a difference. It's a slim chance on that but doesn't have much cost.

If you have an EVIC on your truck look at the temperatures of the sensors before you start. Look for something that's out of line. A temp sensor could be a bit out of whack.

-Tom

[Matt Schrum]

Tom,
Thanks for digging. I have a OBD-II reader (in addition to the info the dash screen displays) and I didn't think about flipping through the readings ahead of time to see what is out of whack. I have a feeling it'll take a few times for me to gather much more information on this issue, but I'll try and keep the thread updated.

[Bill Dufour]

Turn key to run position and listen for the fuel pump to build pressure then shut off, should take 3-5 seconds. Next turn key to start position.
Also you may be using the wrong gas as in spring and fall winter/summer gas could be wrong gas for todays weather. Not much you can do about that.
Bil lD

[Matt Schrum]

Well, I'm still stumped as to why the fuel line is losing pressure when the weather warms up over the day-- but hopping in and flipping the key to the "run" position while I buckle in, etc. seems to do the trick. We've had one or two days that probably should have caused my issue to re-emerge, but then yesterday's temp changes definitely should have. With the key in "run" for a couple of seconds before starting, the truck fired right up.

I'll keep an eye on it, maybe it was a one-off, but hopefully my change in routine will make this issue a non-issue. Thank you everyone for your input!