lopey idle when cold

[mjtjnj]

What controls the mixture when the truck is first-thing-in-the-morning cold? I have about 400mi on my new 2.5 with ALL NEW SENSORS (except TPS, other thread), and it runs very rich and is lopey at idle when I first start it up. It's in the 40s in the mornings here already (30s at night!). It's not stalling, or a major problem, it just seems a little rough until a few blocks of driving. Never did that with the beat, old engine and original sensors!

:)

[Wildman]

The Renix system runs in "open loop" at start up, and when it hits operating temperature, the ECU takes over and makes the necessary adjustments.

 

This might sound odd.......but disconnect the negative battery terminal for about 20 minutes, and then re-connect it, and see it that don't help with the cold start ups and running.

 

That's a normal thing to do with a OBD I & II systems, but I'm thinking that your New sensors might be holding residue voltage, and this will drop all voltage out and 'clear' them.

 

Did you change out the O2 sensor???

[FxRacing282]

more or less a open loop. its actually cold start mode. until the O2 sensors heat up and are at operating temp which is like 600 degrees.

but really did you know that a vehicle will only get 1/3 the gas mileage when you drive it cold? 1/3 of the gas goes into the cylinder, 1/3 goes out the exhaust valve and the other third gets burnt. honestly i wouldn't worry about it. but i do recommend letting your truck warm up for a few