[pachinko78]

On cold mornings(about 10 degrees) my 4.7L Dak starts quickly and runs fine for about 2 minutes. It then develops a miss until the engine starts to warm up then the miss goes away. When it's not so cold the miss never happens. The plugs (Autolite 5224) are new and the coils are properly seated and connected. No engine codes show up. What gives? Is one coil going bad? If so, how can I test the coils to find the bad one?

 

[tenacious0311]

mine does teh exact same thing and i was told not to worry about it.......comforting i know.....

 

[pachinko78]

I guess I don't have to worry about it, the miss went away. Hmmm....

 

[MoparREVolution]

How many coils does the 4.7 have?

 

[2Evil4U]

Almost sounds like the fuel injection controller could be going into closed loop before the engine is warmed up enough. That would cause the motor to lean out a bit until the temp got to where it is supposed to be for closed loop operation.

Might be worth checking the output of the engine temperature senders to see if one has a bad spot in it on warm up.

Just a thought.

 

[pachinko78]

MoparREVolution, the 4.7 has 8 coils.

2Evil4U, wouldn't a bad temp sensor make the computer record a code? I've checked, no codes. Anyway, the miss has disappeared.

 

[2Evil4U]

Not sure. All the temp sensor would do is say that it is warm enough to change fuel maps. If there is nothing wrong but reading a slightly high temp a little early, it might not show a code. If the sensor failed and read nothing, then I could see a code popping up. Just an oddball theory.

 

[MoparREVolution]

MoparREVolution, the 4.7 has 8 coils.

2Evil4U, wouldn't a bad temp sensor make the computer record a code? I've checked, no codes. Anyway, the miss has disappeared.

Dang that sucks. Glad my truck has 1. :banana2: