Only happens when cold, none of my other cars do this. No FF codes.
Stomp on gas and bog/sputter when engine is cold, any ideas appreciated.
When warm this does not happen~

 

AFR gauge FTW!

 

OK if the air to fuel ratio is off (what is it supposed to be anyways??), what does one do to fix it?

 

well, if its off, youd have to fix whateveres wrong with your jag and throwing it off. Vacuum gauge is another wonderful tool.

 

also fuel pressure gauge.

 

Fuel P is steady at 38 psig, book states 35-45 psig as a range

 

When cold the engine needs to draw more fuel, so if fuel pressure is OK as it seems to be, the injector pulse is too short, indicating perhaps your engine temperature transmitter is not right.

The two biggest influences on fuel supply are (1) engine (coolant) temp and (2) mass air flow. As you don't get the problem when engine is hot indicates to me it is not a mass air flow measurement problem

 

the intake air temperature is also a major factor in AFR. although im not sure if it applies to the 5.3