Choke - Initial Start Help

[srgould41]

It started perfectly again last night. I'll have to wait for winter to know if this resolves the issue completely.

[lionelhutz]

Interesting. Does anyone know what that is actually doing?

The CATS Tuner $42 definition seems to call it the "Air Fuel Ratio at Startup Vs. Coolant Temp. (Choke)" and describes it as "This cold engine AFR vs. coolant temperature table is used to control engine AFR after the ECM has gone into “closed loop” and prior to reaching normal (or near normal) operating temperatures."

But that doesn't sound right to match what you're finding. It would seem like this value is subtracted from some starting AFR number when calculating the desired AFR for the engine when it is first started. Maybe it uses this to calculate the AFR until the closed loop timer expires????

[srgould41]

I agree it does not make sense. Going back over my notes it turned out that my cold idle was related to changes I made in Open Loop idle settings that were to fix my CLOSED loop idle problems. Some settings seem to do the opposite of what I would expect them to do.

Interesting. Does anyone know what that is actually doing?

The CATS Tuner $42 definition seems to call it the "Air Fuel Ratio at Startup Vs. Coolant Temp. (Choke)" and describes it as "This cold engine AFR vs. coolant temperature table is used to control engine AFR after the ECM has gone into “closed loop” and prior to reaching normal (or near normal) operating temperatures."

But that doesn't sound right to match what you're finding. It would seem like this value is subtracted from some starting AFR number when calculating the desired AFR for the engine when it is first started. Maybe it uses this to calculate the AFR until the closed loop timer expires????

[ony]

them open loop settings in cats tuner open loop vs map, open loop vs coolent temp,cranking afr, I change an leaned them out but I live around huntville tx where air temp outside stays pretty warm. my truck is worn out but the settings was putting enough fuel in that wasn't needed I think it was washing the oil off the cylinder walls, oil consumption went down a little mpg went up a little as for the operation smooyhed out a little in open an closed loop, I have a v6 though .