Start very hard below 20 degrees F.

Hello,
I have a 97 4.0 SOHC Eddie Bauer explorer that runs great, except for the first start of the day when the temp is below 20 degrees. onces its started, it runs fine. In order to start the truck, you have to put pressure on the gas until you hear the RPM pick up on its own and slowly get into the proper RPM range. This morning the temp was around zero and i had to hold the accelerator down for about 3 min before the truck would stay started. if i were to let up on the gas, the RPM would go so low it would stall. This happend all last winter and i would love to fix it this year as i want to install a car starter for my wife.

Any help would be greatly appreciated.

Thanks-Ryan

It sounds like the "cold start" circuit isn't working. I'm not to familiar with the 4.0 fords, but the 4.0 Jeeps had a sensor in the intake that told the computer it needed a rich mixture of fuel on initial start up. Oh, I think it might be in the air box( air filter) Look for a sensor there, at least thats were it is on the 5.4 ltr broncos. Also is the engine service light on? If so its throwing a code, and your local parts store might be able to read the code to tell you what is not working properly. Sorry I can't be of more help. Also look at your ignition system(plugs,cap,rotor) makesure their in good shape.

Make sure you have the proper weight oil, 5-30 I believe.

Thanks for this information. I will have to check this out. It sounds logical. If almost acts as if a choke isnt getting applied and therefore running lean. Once the temperature gets above 10 degrees, i will look into this. this morning i went to start the truck and the temp was -11. oh to live in New Hampshire! Thanks again for the help and i will let you know what i find.

-Ryan

I think the air temp sensor is somewhere in the air tube going between teh air box and the intake.

My wife's exploder was running rough and stalling at idle only on the cold mornings. Approx 50 degrees and colder. It is a 1999 ford exploder xlt sohc v6. I replaced the o-rings on the intake manifold and it fixed the problem. I have had the problem for approx 2 years. A few times toward the end I would get a check engine light and finally the light just stayed on. The code was lean bank 1 and lean bank 2. I changed out the idle air control valve and it did not help at all. That was when I decided to change the intake o-rings and it fixed the problem. I did the job myself and it took approx 3 hours. The o-rings were blue in color and were not pliable. They were real stiff but would bend. The replacement o-rings were from felpro and they were silicone o-rings and were very pliable. Just get a book and some tools and you can do the job yourself. Good luck, Brian