I have a 1996 windstar with 223,000 miles on it. It's been a very good vehicle but for the last few years it will run really rough on a hot start for about 20 seconds and then run fine from then on. no codes ever . Lately it seems to be getting worse. Any ideas?

 

Before anything else , when were the spark plugs and wires last replaced?
What else has been done recently, last 6 mos.

 

By the way it's a 3.8L. Spark plugs have less than 5000 miles on them. The wires are original. It starts great when cold. Fuel injectors are original also.

 

Replace wires and coil pack.

Do you have a plastic intake manifold?
Is the DPFE sensor made of metal or plastic?
Are the intake manifold runner motors vacuum operated or is it a single electric motor?

If replacing the wires and coilpack don't cure the issue have a look at the spark plugs as well even thought hey are nearly new. Their image could tell a story.

My questions become pertinent if the trouble persists.

 

The upper plenum is plastic and the DPFE sensor is metal..Probably aluminum. I,m not sure what you mean by motor or vacuum mover. Thanks for your help. I'm not sure when I'll get to changing the coil pack or wires. It's pretty cold here in Cincinnati.
I've had this vehicle since new. (17 miles on odometer) It's been a great one. Chuck

 

The DPFE sensor was later changed to plastic because the metal ones corroded inside. You can get a plastic one from the junk yard.

This diagram shows the vacuum controlled IMRC actuators. The round pods with a rod sticking out, called "vacuum control and bracket assy":



and this is how the electrical version looks, a black box with 2 rods extending:

There are small plastic bushings on the rods, which get lost and that causes rough idling. The vacuum style actuators make vacuum related trouble. Look for leaks.

 

injector leakdown can cause a hard start after a hot soak.

Its easy to rule out...install a fuel pressure gauge, start the vehicle, shut it off and record the pressure. Note the pressure drop after 5minutes.

 

Good point, I didn't even think of that. Using a fuel system cleaner or an Seafoam treatment might help in that situation.

 

thanks guys..I thought about leaking injectors, tried a bunch of injector cleaner, and it helped for about a week. I went to store to get a new set of spark plug wires and a coil pack (per Bluewind) and a Ford mechanic was there. He said that it most likely was one or two injectors. He suggested doing a hot start with an analizer on the van and see which spark plugs are fouling as it's running rough. Think I will try that. Thanks for your help and comments. I will let you all know how it turns out