99 Windstar - rough idle at stop or at start

[MasterChief]

My 99 SEL Windstar (98K miles) has developed a rough idle when coming to a stop. Also when started the engine struggles for 30 seconds and then corrects itself. Then the van runs fine. The problem is very intermittent. No codes are being stored by the computer. So far we have had it in the shop twice. So far they have cleaned the throttle body and replaced the IAC valve . But the problem still occurs. Help

[wiswind]

I get this in COLD weather after running the engine, shut it down for a short while (like 15 minutes or so) and restarting.
I clears up after a very short time.
I get this ONLY in cold weather, after shutting down a WARM engine for a short time.
Why? I don't know.

My engine runs just fine otherwise.
I have had this happen for many years.....many miles.
I am guessing, at this point, that it has to do with vapors/condensation in the intake.
I installed a "catch can" in the PCV line, and it still does it.
I am guessing that it is not a serious issue in my case.

[AvalonJohn]

Replaced plugs, wires, fuel filter yet ? I had a 99 and this turned out to be the problem about 96K miles. same thing your describing.

AJ

[jayjp200]

I have the same problem on my 1998 Windstar. I have replaced plugs, wires, Idle control valve, MAF sensor, air intake temperature sensor and fuel pressure regulator. The problem is the same and get this many times.
Only thing left is now the injectors.
One more thing is that the mileage has got worse.
Some one please help.
Thanks.

[Rotorman]

Originally Posted by MasterChief

My 99 SEL Windstar (98K miles) has developed a rough idle when coming to a stop. Also when started the engine struggles for 30 seconds and then corrects itself. Then the van runs fine. The problem is very intermittent. No codes are being stored by the computer. So far we have had it in the shop twice. So far they have cleaned the throttle body and replaced the IAC valve . But the problem still occurs. Help

Hello Masterchief, I had this problem a few years ago. I performed a thorough analysis of the engine managment systems and came up with a lazy tps sensor. This sensor is easy to check except for an intermittent sticking of the spring of the sensor which mine did. I replaced the sensor with a borg warner brand and since then never had any issues. The part is about $20 bucks or so. I hope this solves your problem.

[jayjp200]

Rotorman.....THanks for the response. I am going to change my 98's TPS.
One more question...Is this the reson for very low mileage also.
Thanks.

[Rotorman]

Originally Posted by jayjp200

Rotorman.....THanks for the response. I am going to change my 98's TPS.
One more question...Is this the reson for very low mileage also.
Thanks.

No that sounds like an additional problem, you might want to try Berrymens chemtool b12 fuel injector cleaner. good luck

[jayjp200]

Rotorman,
I have replaced plugs, wires, Idle control valve, MAF sensor, air intake temperature sensor and fuel pressure regulator already.

I have also added many different fuel injector cleaners and have not received any help. The mileage is only 6km per liter on highways.
The engine runs very clean as per the emissions test.

Please reply.
Thanks and regards,
Jay

[wiswind]

For spark plugs, Motorcraft and Autolite make the "Double Platinumn" plugs that are specified for our vehicles.
Bosch plugs have been noted to cause problems in our vehicles, so if you used those, I would change them out.

I would also repeat the recommendation of a can of Berryman's B-12 Chemtool in each of the next 2 tanks of gasoline.
I know, it is yet another brand, but I went down the list of lots of cleaners, and told my mechanic this when he handed me a can of the Berryman's......he told me that most of the other cleaners are detergent based, and help to KEEP the system clean, but the Berryman's is Solvent based......anyhow, I followed his advice.....and it DID work.
I needed 3 treated tanks to completely clear it up.....but saw a big improvement after 2 tanks.
My problem was bad enough to light the CEL each time I drove the vehicle.

You will find that the Berryman's is one of the less expensive products on the shelf, and not in a fancy container.......but it DOES work.
I run a can through every 3 months.

[Seeler]

I accidently created a rough idle when warm by reversing the hoses for the Differential Pressure Feedback (DPFE) sensor the EGR valve uses to meter flow. Since you have dealt with the ignition and air induction systems, the EGR system may be your culprit.

[Doug360]

My first thought would be the TPS as already indicated on this thread. If not, I had a similar problem with intermittent rough idling. At first I had no codes but after a few months I got the infamous 171/174 code. After doing the TSB the problem was solved.