2000 Windstar rough idle problems, etc..

Thought I may have fixed my problem with our '00 Windstar last week when I had the MAF sensor replaced along with the PCV valve. We have been having rough idle, stallout problems for a few months now with no rhyme or reason to the patterns. Read many posts that I found and seemed to be pointing to the MAF. The CEL is not coming on nor any error codes.(can you get error codes w/o the cel lit?) Wants to die out after starting, at stops and sometimes when coming to a stop when the idle starts dropping below 500. My wife has to brake and keep foot on gas to keep running. Very dangerous. Had fuel filter replaced also 6-8 months ago. Have seen some posts about oxygen sensors, fuel pump relay, etc. Could it possibly be a catalytic converter problem? I got my hands on the Haynes repair manual and have been reading through it some. Nothing has jumped out at me. Looking for any help!

P.S. Thanks for your reply a few weeks ago hecticmom. Is your van acting up again or did that fix it?

Have you checked/cleaned or replaced the IAC?

Thought I may have fixed my problem with our '00 Windstar last week when I had the MAF sensor replaced along with the PCV valve. We have been having rough idle, stallout problems for a few months now with no rhyme or reason to the patterns. Read many posts that I found and seemed to be pointing to the MAF. The CEL is not coming on nor any error codes.(can you get error codes w/o the cel lit?) Wants to die out after starting, at stops and sometimes when coming to a stop when the idle starts dropping below 500. My wife has to brake and keep foot on gas to keep running. Very dangerous. Had fuel filter replaced also 6-8 months ago. Have seen some posts about oxygen sensors, fuel pump relay, etc. Could it possibly be a catalytic converter problem? I got my hands on the Haynes repair manual and have been reading through it some. Nothing has jumped out at me. Looking for any help!

P.S. Thanks for your reply a few weeks ago hecticmom. Is your van acting up again or did that fix it?

No i havent. I read about this in the repair manual. Seems pretty easy to get to. What exactly does the IAC do? Any special tools or procedures needed for replacing? Have done some mechanical work on my vehicles over the years but ever any repairs that have had to do with vacuum lines, emissions stuff, etc. Our mechanic seems fair but I'm starting to get tired of spending money on this vehicle. Thnaks for your reply!

The Idle Air Control Valve is mounted on the throttle body and regulates the amount of air that bypasses the throttle plate. It receives it's signal voltage from the PCM depending on the PCM's input sensors to control idle speed.
From my 95-2003 manual the first thing to determine is if it's getting a signal. With key in Run position, probe the harness side connector of the IACV's plug. Voltage should be 10.5-12.5 volts if it's receiving a good signal from the PCM. If so check the resistance across the IACV's terminals itself. This should be 6-13 ohms, otherwise replace it.
Also check for an internal short by measuring the resistance between each terminal and the IACV body, it should be 10,000 ohms or more. If it's less then there is an internal short and it needs replacing.
If all this passes, then remove the IACV to check and clean the internal pintle and ports and to allow free movement. After cleaning and with IACV removed, reconnect plug and turn key on and off, (Do Not Start) pintle should freely move. Install with a new o-ring lightly lubed with clean oil.

The Idle Air Control Valve is mounted on the throttle body and regulates the amount of air that bypasses the throttle plate. It receives it's signal voltage from the PCM depending on the PCM's input sensors to control idle speed.
From my 95-2003 manual the first thing to determine is if it's getting a signal. With key in Run position, probe the harness side connector of the IACV's plug. Voltage should be 10.5-12.5 volts if it's receiving a good signal from the PCM. If so check the resistance across the IACV's terminals itself. This should be 6-13 ohms, otherwise replace it.
Also check for an internal short by measuring the resistance between each terminal and the IACV body, it should be 10,000 ohms or more. If it's less then there is an internal short and it needs replacing.
If all this passes, then remove the IACV to check and clean the internal pintle and ports and to allow free movement. After cleaning and with IACV removed, reconnect plug and turn key on and off, (Do Not Start) pintle should freely move. Install with a new o-ring lightly lubed with clean oil.


Thanks for the info. I need to learn more about the PCM. I think some of my pages are mssing from my manual. What does the PCM do? Is it like a ECM? I replaced one of those once on a '85 or '86 cutlass. Have been reading a lot of info on TSB 3-16-01(isolator bolts). Could these be creating the systems were having. Van really seems to be running ok while driving. Just wants to die out when almost to a complete stop or at a stop when it should be idling. Thanks in advance for any help. This forum is great.

PCM is the computer that controls the engine.
IAC.....controls pretty much all the air into the engine when your foot is not pushing down on the accelerator.
The IAC can 'stick' causing your engine to stall.
The IAC has to act pretty fast....as we remove our foot from the accerlerator.....and it has to jump in...and open up to let air into the engine.

The IAC is mounted on top of the uppper intake manifold....right next to the throttle body.
I would spray some "Sea Foam" into it....
The IAC is held in place by 2 bolts, and has 1 electrical connection. Remove it....spray some of the SeaFoam, it is a penetrating oil, into it......and re-install. If that does not clear up the problem.....just replace the IAC.....

Some fuel system cleaner into the gas tank would be a good idea.....Cheveron "Techron" or....my favorite....Redline Complete Fuel System Cleaner.....

Please post back as it will help others

You can find FREE repair information at www.autozone.com.

Windstardad
You may want to replace the fuel pump relay...it can give your symptoms as it begins to fail. Use the glove box manual to locate.

About $8 at dealer.

had this problem on a 98 windstar, the build up inside the throtal bodie was the the problem, where you air filter is. Take a rag with some brake cleaner on it and wipe out the bore, push the butterfly open all the way and clean as much as posible.

worked for me , maybe for you

had this problem on a 98 windstar, the build up inside the throtal bodie was the the problem, where you air filter is. Take a rag with some brake cleaner on it and wipe out the bore, push the butterfly open all the way and clean as much as posible.

worked for me , maybe for you

Same here with my '98, I didn't use a rag though. While running, I used some intake cleaner and sprayed it through the air tempature sensor hole with a straw while opening the butterfly valve with the throttle cable. The ATS is on the flexible part between the air filter and throttle body.

Cleans out your whole intake system pretty good.

have you done the 171/174 repair as outlined in the sticky at the top? Have you checked all vac lines?

Piper

I agree with northern piper... do the 171/174 fix.

My wife's 2000 Windstar SEL had 156,000 miles on it, and the engine was running very rough, I thought the trans was going again (the trans has went out 3 times before (I have a life time warranty on trans now)). I also had the engine light come on for the 171 code.

The fix was only $30 for me (bolts & gaskets), but it took me 6 hours to complete (I'm slower than most) this past Christmas break. The van runs much much much better now... its like night and day. If you choose to do this fix there is a link that provides detailed pictures and instructions, which makes it 10 times easier.

Before I did the 171 / 174 fix, I use to switch out the EGR valve and sensor every Spring (March / April), which also helped it ($80 - $100). So far this year, I have not had to switch the EGR valve or sensor.

Cheers!

Fulcrum