02 Windstar running rough between idle to about 3,500 RPM

[akakwo]

Hello everyone. I am at my wits end and need some help on my 2002 Windstar. I purchased it used in 2003 and now have 115,000 miles on it. It started running rough this past weekend. It runs rough between idle to around 3,000 to 3,500 RPM and does not produce a code. It is almost like it is missing but it is not constant. At idle, it can run good for a minute and then seem like it is going to stall and then run good again. When taking off from a stop till about the 3,500 RPM, it runs rough every time.


Late last year I replaced the fuel pump and filters, spark plugs, wires, and coil pack (about 6,000 miles on these parts so far). Earlier this year, I replaced the 2 catalytic converters, and all 4 oxygen sensors.


This has been accomplished so far for this problem:
Replaced fuel pump relay with another: no change
Checked the IAC valve: good voltage and resistance
MAF and IAT sensor: looks brand new
Coil pack: still looks good; resistance checks good
Plug wires: look good; checked for sparks in the dark—did not see any sparks
Plugs: look fairly good
IMRC: all clips rotted. Replaced and the idle seems to have settled but still runs rough when taking off from stop
Borrowed a scanner from a buddy and it does not show anything out of the ordinary (that I can see anyway). The MAF values change .8 to about 7 volts under load. IAT is about right. It shows something for the O2 sensors but need to read on it a little more to make heads or tails of it. Now, he suggested using carb cleaner on vacuum lines. The first thing I did was to spray where the IMRC goes into the intake. The one closer to the cabin did not produce a change. However, when the other was sprayed (just a shot of it), the RPM went up and down (between 500-1000) before settling. I then shot it for 20 seconds which almost caused it to stall, then it went to 1000 and then settled. I repeated both several times and always produced the same results. I tried this on a vacuum hoses which all produced no change. I spent a few hours looking for problems such as this to include any IMRC issues and could not much. Could the bushings on the IMRC rods be causing all my problems?

On a side note: the van has been missing a little over the last few years but not enough to cause me to spend much time on it. About 3 years ago I changed the EGR and DFPE sensor which helped a little.

Any ideas?

Thanks,
Bill

[Windstartled]

Does it idle rough when in park an neutral or only with transmission engaged?

[akakwo]

It runs rough in park, neutral, and in gear.

Also forgot to mention before that the TSB for isolator bolts was performed several years ago.

Bill

[akakwo]

Problem solved........finally...........I have a habit of keeping certain parts and still had the old coil pack and plug wires. Put the old coil pack in and it ran fine. Returned the bad one since it was under warranty. That problem was frustrating; I was about an hour from taking it to a mechanic.

On the bright side; I did fix an exhaust leak though that was causing a high long term fuel trim.

[Windstartled]

I love a happy ending