Jackmup

I was wondering if anyone has resolved this issue.
3.0 cold start misfire

My coils, plugs, vacuum lines are all new.
I cleaned and tested the injectors, they're good
timing belt is new, No oil leaks at all.
No oil leaking down spark plug hole. Valve cover gaskets new.
I am going to test the wires to cylinder 4 again, maybe they arc in the morning due to humidity.

This only happens in the morning, sometimes/intermitent and lasts for 20 seconds. Cylinder 4 misfires, P0300,P0304 and sometimes cylinder 1 but mostly cylinder 4. It is much better when it is warm out. and it reset itself a week ago when it was hot all week (I am in Florida)

I have this TSB for a 2.7t and it sounds like my issue. Has any one experienced and repaired this problem? I would hate to fork over $$$ for a flash that doesn't cure the issue. What do you think?

TSB 01-04-06 Update

Programming (Flashing) Engine Control Module (ECM) to Correct Cold Start Engine Stumble (Aug. 30,2004)


After Cold Start Engine Runs Rough. Vehicle may Stumble, Buck and or Shutter on initial acceleration. Engine may stall at idle when transmission is shifted from Neutral/Park to Drive/Reverse.

Condition usually lasts for less than 30 seconds after engine start. Afterwards the vehicle starts and runs without any complaints.

Condition associated with the following DTCs.
P0300 Random/Multiple Cylinder Misfire Detected
P0301-P0306 Cylinder 1 through 6 Misfire Detected

audix

Hi..
Have you replaced the coolant temperature sensor yet?

Jackmup

Thanks for the reply

No I haven't but how would that effect one cylinder?

Jackmup

I have done a little more thinking and have now discovered this

The car was not mifiring between MAY 5th and May 18th.

Between those dates the LOW temp here in Florida has been 70 degrees or higher.

before and since may 18th the LOW temp has been 68 degrees or lower.

What does the car do differently at this threshold?
I did see a code for an outside temp sensor but figured it was just a luxury thing so I ignored it.