My 02 2.3l is missing when the truck is cold. Once it warms up, it runs like a champ. Coil pack is new and so are the plugs. Wires are just a few years old. Anyone know what it could be? Thanks

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Forgot to add, it doesn't misfire constantly while it's cold. It'll run good for a few cycles, then miss for a few, run good, and just repeats until it's good and warmed up.

Checking the fault codes would REALLY be helpful here. Otherwise all we can do is throw guesses at you.

2005 2.3L XL Electronics Tech since '70's

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2005 2.3L XL 5SOD 3.73 K&N
KYB Shocks Husky Toolbox
Alpine / Rockford Fosgate Sound

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No codes as of now.

air temp sensor in the bottom of your air box might be my best guess.
Or mass airflow sensor.

have you tried cleaning either then reseting the PCM?

Mine does the same thing, changed the sensor and it still does it

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1993 XLT 2.3 Single cab 2wd
Used to be lifted, but now low and slow. Flipped hangers and cut coils up front for 2/2 drop. Soon to be 3/4, 17x8, 235/45/17 up front, 245/45/17 in the rear 300K+ miles
My Build Thread:[url]http://www.fordrangerforum.com/project-logs/89577-jldanger-rangers-build-thread.html[/url

There isn't a sensor in bottom of air box, but I just cleaned the. MAF sensor and reset PCM, will let you know results soon.

I think there really should be one at in the air filter box. It's either a air temp sensor or air pressure sensor.

So you're saying that thre is NO OTHER time that it misses?
Can you define "misses" so that we are talking the same language?

Does it do it in open loop and then stop in closed loop?

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How many times have you checked for codes? Have you ever had a pending code?

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

It will idle rough then smooth out and then rough again. Also at take off will sometimes studder real bad and then pick up. And yes, only misses at cold temp.

I just went through something very similiar to this after doing my wires...

in the end it turned out my haynes manual was wrong and I had wired it wrong resultig in misfires and poor performance.

check you firing order again.

Last code was a misfire. Replaced coil pack, reset codes, and problem solved. So I thought. Now that the weather has turned a little colder, it has started missing while the truck is warming up. Once warm, it's fine. So I know it isn't the firing order because that would cause a constant issue. It has been a few weeks since I've checked codes though.

It sounds to me like your air temp sensor then.

02 2 3's dont have an intake air temp sensor.

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2014 F150 xl 3.7 6 speed auto.

It might be part of the MAF? does the maf have 6 wires?

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

i think that's right, it's all built into the maf.