Rough Idle on Restart

1998 3.8 Windstar idles rough after RESTARTING until I rev the engine or wait about 2 minutes. This does not happen when cold starting (or even warm starting. It only happens after a refuel or short stop like 5 or 10 minutes. It has always done it a little bit (I've had it for the last 55K miles of the full 125K it has), but it seems to be getting worse. I keep the van in good repair, and I regularly clean the throttle body every 10k miles including the idle bypass port, but that doesn't seem to have much effect. It doesn't throw any codes and runs perfect all other times. Any thoughts? EGR valve? IAC motor?

I'd like to here from anyone else that has had or solved this problem.

I have been experiencing the same symptoms with my 98 Winstar. It also has 125500 miles on it. No codes activated. This only happens after the van has been off for a short time less than one hour that the restart is a rough idle that has quit a few times. Usually I shift into drive or reverse and the roughness goes away as soon as you start to move. I have not been able to search and find any help for correcting this symptom.:banghead:

I have a 98 win and i have the same problem. but i see no help on this post please someone help us.

There are a couple of current threads that may be helpful, like the one on loss of power/hesitation. There is a temperature sensor called the ECT or engine coolant sensor, and there is the transmission fluid temp sensor that may be acting funny. Just a geuss. Weird, no codes, and cleras up when waiting or putting it into gear and moving. Does the roughness clear up when shifting into gear, but remain stopped with brake on for awhile? That would make me think your transmission range sensor, aka neutral safety switch is not right, dirty,or out of adjustment. If things don't clear up without moving, then that may involve different trans sensors possibly.

Had the same symptoms when I had a lower intake manifold leak on my 96. The coolant was leaking into the intake ports. Are you using any coolant?

If so you should take care of this ASAP, if to much coolant gets into a cylinder it could hydro lock the engine and you could bend a rod. The lower intake can also leak into the engine and we all know what coolant in the oil can do.

My '01 does the same thing ocassionally. No coolant loss and the last oil analysis didn't turn up anything unusual (I was looking for fuel dilution from a possible sticky injector). I just give it a bit of throttle and it clears up in under 5 seconds.

Even a little coolant in the intake shows the lovely low laying smoke out the tailpipe.

When your starting cold.. Its in Cold start.. More fuel High idle dont notice any problems.

After a warm or warmer start. Your coolant temp is warm but not hot. The High Idle comes down Quick. You notice ruff idle more because of this.

Things to do:
Clean the Intake -butterfly

Clean and inspect all of your hoses and main intake hoses for slight oil from the PCV system.
PCV when pulled out of the Valve cover, "Right in front of the Engine with a hose connected" should when shaken, rattle around.

Make sure theres no cracks or holes in the intake tube, From the MAF to intake butterfly - thottle. You have to flex the hose to see them. Also replace the air filter while your at it. Every 15k or so..

Spark plugs worn, plug wires etc. Worn plugs will play with your idle speeds.. Just quick check them..

O2s should just be changed around 100k some cars say 60k at replacement for the best Fuel mileage. They can be tested tho if you dont have the money..

IAC dirty Idle air control does all of your Idling!! also right on the Butterfly thottle area. It bypasses the air around the butterfly...

EGR ports Clogging common in these.. Intake mana has to be removed and needs new gaskets and bolts seals Alot of talk about these on hear with a FYI post with photos. Alot of help here..

IMRC Runner control Make sure those linkages are connected.. They should be closed at Idle, and when your Goosing the throttle they will open! While driving with them disconnected, they will close and open themselfs giving odd problems including stalling shifting into Drive or Rev. They are on the front of the engine under the intake manifold. In the V part of the engine - on the Pass side of engine compartment.

Air leaks in the intake will set a Engine code with Engine light.. Very common but not always..

Just a quick inspection should give you an idea of whats going on, since your PCM shows no codes, its not something major..

Dont Forget,, If the battery has been changed, Was the Idle setup correctly?
You can relearn the idle by disconnecting battery for a few mins. Connect battery, and start engine. Let it run until its HOT Idling to 700ish rpm.. Better to do this when engine is already hot.. This way you wait two mins or so.. They say 1 min - NO LESS and in Park!!
Then, Put your Shifter in Rev 10 seconds or so, Then Net, then Drive, then 2, then 1st.. If you have OD and D Just do them ALL!
Then back to park, then Take it for a DRIVE!

Friends,
I have done all of the above and the funny rough idle after warm start occasionally does not seem to go away.

Friends,
I have done all of the above and the funny rough idle after warm start occasionally does not seem to go away.

These PCM are programable.. Only the dealer can reprogram it and ther maybe a new update for starting after hot soak.

They did the same for shifting into o/d They reprogramed the PCM so its not so touchy going in and out of o/d.. I would look into it, Ther maybe a TSB on your Year - Month of the Van.

Thanks, I have 98 Windstar 3.8 liter.

Funny; ours does the same thing. I will be replacing the intake gaskets along with some other clean up and tune up items..if I have any luck I'll let you know.

Funny; ours does the same thing. I will be replacing the intake gaskets along with some other clean up and tune up items..if I have any luck I'll let you know.

TSB - IAC stickin check and replace, 1 to 4hrs after hot soak..
TSB - Ruff Idle and Hard start Cold temps after hot soak.. Air Temp Sensor check and replace.

Fuel pressure Check valve, "In fuel pump" Extended cranking and rough idle - Check fuel pressure before and after hot soak. Fuel returning to tank while sitting.

Still looking for others, they are the few Ive found on a few different years.

None of these say Engine light or any codes, so I would say these are codeless off the spec of good, but pcm wont set a code.