I have a similar problem with my 95 F-150. When it sits overnight and it is cold and damp outside it acts like its flooded. It will finally start after a lot of cranking but runs real rough until the raw fuel is burned. It reminds me of the older carburated engines where the choke would get confused in damp weather. I am guessing that it is a sensor, but unsure what sensor it would be. Any help or lessons learned would be appreciated.

 

Hi bravo and welcome to FTE

I'm going to move your question over to the pre 97 forum where you'll probably get more answers.
What size engine do you have?
Have you tried doing anything to it to solve the problem?
How old are the spark plugs?

 

Thanks for directing me to the right forum.

It is a 4.9L (In-line 6 cyl 300ci). I haven't tried anything yet, still don't understand the cause. I do not suspect spark plugs at this point (could be wrong). I beleive that it is a flooding problem, I do not know if there is a device similar to a choke on a fuel injection. The problem only occurs when it is cold and damp outside. The truck has ~87,000 miles. The plugs where last changed at 60K.
I have also started to notice a chugging at slow speeds when the engine is still cold.

Any advice is appreciated.

 

This has happend to me a few times. Damp or rainy days gave me a fit on a couple of vans in the past. I could open the hood and let the sun dry it out for an hour or so, then it would run like a champ, until the next damp morning.

Check for moisture inside the distributor cap. A slight oil film, plus moisture will give you problems.

Also, if the plug wires are old, they absorb moisture, and when you try to start the engine, they short out so the plugs don't get full shot of spark, if any.

I think if you replace the cap, rotor, and plug wires, your problem will be cured.

 

Thanks 94 van. I replaced the dist cap, rotor, wires and plugs. After a month of cold damp weather the problem has not reared it ugly head.
Appreciate the advice.