1998 3.8l Windstar

My windstar, at idle, is kind of sputtery acting like it wants to cut off. It actually has cut off once when I was at an ATM. When I accelerate it does fine. I checked the ohms on the IAC and it was normal.(10.5) The check engine light is not on so I am assuming there are not any codes. Can you test the MAF or the o2 sensor like you do the IAC? Any other thoughts? TIA!

Just check or change the basics - plugs, wires, coil, fuel filter, air filter so that you know what you're starting with if you need to investigate deeper. Problem with these computerized ignition systems, they can compensate for conditions so bad, you wouldn't know there may be a problem starting like the old systems.

You can clean the MAF sensor with non-residue electronics cleaner, there's a tutorial on here somewhere. Check the Throttle Position Sensor, too. Might also want to try spraying some intake cleaner through the throttle body.

include with the basics all vac lines, particularly the fuel regulator (upside down "U" line). I had this one come loose on my van and it caused symptoms as you've described. Check out this pic http://img222.imageshack.us/img222/2957/img1414newlabkm2.jpg. (http://img222.imageshack.us/img222/2957/img1414newlabkm2.jpg)

include with the basics all vac lines, particularly the fuel regulator (upside down "U" line). I had this one come loose on my van and it caused symptoms as you've described. Check out this pic http://img222.imageshack.us/img222/2957/img1414newlabkm2.jpg.

Is that a '98?

I ask because I notice a couple of differences in mine...

1. Your PCV valve is on the front valve cover? Mine is on the back. Should it be? Should I have one on both? If that has been my problem this whole time I'm going to drive it over a cliff.

:banghead:

2. Your upper air intake and FPR vacuum hose are different.

sorry, forgot to mention the 2000 vs 1998 differences. Your van may be different yes. Point being, check all vac lines. Sorry for any confusion.

P

Thanks, I will check those things. Also the cutting off has started to get worse.

1998 has the PCV valve in the rear valve cover.
The front valve cover has the "breather" that has a hard black plastic line that goes to the back side of the big flex line that is between the air filter/MAF tube and the throttle body.

IAC has a motor in it that drives a small opening to permit more/less air into the intake......a way for the PCM to control the idle speed.
It can get dirty....and stick......so cleaing is the first step to take in fixing it.
Common failure mode for this is stalling when you have your foot off the accellerator.....like when pulling up to a stop light......in parking lots (turning steering wheel at idle makes it worse).

Fuel pressure regulator is on the passenger side of the upper motor......note was to make sure that the vaccum line to the top of it is secure.

As mentioned......make sure that all the vaccum lines are connected.

Also....double check to make sure that the IMRC is working.
On the '98, they are still vaccum driven.....they will be OPEN with no vaccum (also with motor not running) and close with vaccum (when you start the motor).
I have pictures that show these in the pictures that they link in my signature takes you to.
If these are not working correctly.......usually staying open is the failure mode on our older windstars.....you will have poor low load issues.

Of course....make sure that you are up to date on all the routine maintenance things, like fuel filter, etc.

Thanks for the input guys. I haven't got to check anything yet because it has been raining for 3 days here. One more question. I also noticed that when the van is cold it seems to idle fine, but after it is driven for a bit and gets warmed up is when it gets worse. Does that narrow any of the culprits down?

Here is the latest. I took off the IAC and cleaned it. It did not look that dirty. I also plugged it up while I had it off and turned the key on and off and it does not move inside. I can feel the motor part of it working but it is not moving so I am assuming that this is the problem and I need to get another. But one thing, when I tested the ohms it showed normal. Does this make sense?

Here is the latest. I took off the IAC and cleaned it. It did not look that dirty. I also plugged it up while I had it off and turned the key on and off and it does not move inside. I can feel the motor part of it working but it is not moving so I am assuming that this is the problem and I need to get another. But one thing, when I tested the ohms it showed normal. Does this make sense?

Maybe the problem is mechanical and the electric motor is working?

I don't think they're very expensive.

My van is idling a little rough, I think I should check mine, too.

What should my vacuum pressure be?

The IAC pretty much is only used when the engine is at idle and a load is put on it. So since you have proven that it ohms out correctly, the best thing to do is to see if it actually is working. The easiest test is to turn the steering wheel from stop to stop while in park, then while in gear with foot on brake pedal and see if the engine can keep idle or struggles. If the latter, then bad IAC. You can also test it with the ac, turn wheel, high beams, rear defrost, wipers and foot on brake all at the same time to really load up the engine to see if the IAC can compensate for the load.

You said the idle seems to get worse after it warms up? If you cooling system is full with no air trapped inside, your heater works, etc., then your Engine Coolant Temperature sensor may not be working correctly. The PCM uses the temp info to determine what the fuel to air ratio should be. Do the fans come on as expected when the van gets hot? If so, the ECT is probably fine. It is located just over the thermostat housing that connects to the upper radiator hose. You can check the ohms on it cold and hot to be sure it's ok.

Now on this business of intake vacuum, I refer to Ford's TSP. It's for 95 models, but since it's for the same engine, I expect it to be the same or close enough. I won't post the whole section as it is quite large and probably goes beyond what you need, but if you want all of it, then PM me and I'll try to get it to you that way.


Intake Manifold Vacuum Test

Bring the engine to normal operating temperature. Connect Rotunda Vacuum/Pressure Tester 059-00008 or equivalent to the intake manifold (9424). Run the engine at the specified idle speed.

The vacuum gauge should read between 51-74 kPa (15-22 in-Hg) depending upon the engine condition and the altitude at which the test is performed. SUBTRACT 4.0193 kPa (1 in-Hg) FROM THE SPECIFIED READING FOR EVERY 304.8 m (1,000 FEET) OF ELEVATION ABOVE SEA LEVEL.

Hope this helps.

Well, I replaced the IAC and it is still doing the same thing. Of course it starts up fine and isn't rough until it warms up. I guess my next thing is the ECT but I don't see how you get to it.

Hmm, since you say it runs fine when you give it the gas, I kind of doubt the ECT is your problem. Never-the-less, first of all, you should be sure you don't have any trapped air in the cooling system, as that will give incorrect readings. Second, typically, a problem with the ECT circuit will produce a trouble code. Third, you can test it while in the engine with your ohm meter. With the wiring to it disconnected, you can expect around 40.5 k-ohms at 65 deg F., and with the engine at operating temp., 180 to 220 deg F., 3800 ohms down to 1840 ohms. You should also check to see if you have around 4.5 to 5.5 volts at the connector to the ECT while disconnected. You can check this if you want with just the key on but engine off, I'm pretty sure.

The ECT should be screwed into the top of the intake manifold just beyond the thermostat housing in a straight line from the upper radiator hose. The ECT has a TWO wire connector to it, not one. The temp sending unit for the dash temp gauge has a single wire to it. The ECT also has a gray plastic body with a brass base. All of this may be buried under the coil and throttle body/snorkel, so you may have to trace your upper rad hose to it. The thermostat housing is also to the right of the egr valve when looking at the back end of the engine. Autozone.com may have some good pix if you need it. Wiswind has a link to pix in his signature area that may be of this too. His 96 should be the same as your 98.

Intake Manifold Vacuum Test

Bring the engine to normal operating temperature. Connect Rotunda Vacuum/Pressure Tester 059-00008 or equivalent to the intake manifold (9424). Run the engine at the specified idle speed.

The vacuum gauge should read between 51-74 kPa (15-22 in-Hg) depending upon the engine condition and the altitude at which the test is performed. SUBTRACT 4.0193 kPa (1 in-Hg) FROM THE SPECIFIED READING FOR EVERY 304.8 m (1,000 FEET) OF ELEVATION ABOVE SEA LEVEL.

Hope this helps.

I think that's about what I read at the EGR valve port, I'll test everywhere else and report back.

I suspect it is the line going through the firewall to the A/C since I have the defrost only condition.

I just thought of a simple test...

I've got a code reader in my car, I could disconnect the white a/c vacuum tube and put a plug on the valve where it attached and clear the codes...

Your defrost only working condition is very useful information to share and would help us help you get to your problem faster!?! Now you're getting somewhere! It sounds like you had gotten some codes. What were they? Chances are they were created by the leaking vac line to or at your hvac. That would create a lean condition that would code. Keep up the chase and us informed.

Your defrost only working condition is very useful information to share and would help us help you get to your problem faster!?! Now you're getting somewhere! It sounds like you had gotten some codes. What were they? Chances are they were created by the leaking vac line to or at your hvac. That would create a lean condition that would code. Keep up the chase and us informed.

Sorry, I thought the idea that the A/C not working right could effect the engine just seemed crazy.

I'm getting the infamous P0171 and P0174, nothing else. Gaskets and bolts from the block up are new. The emission and air intake components are about two years old, so I don't suspect any of those. It's been sitting in my driveway for two years. A/C controls are new, too.

I've got some vacuum plugs I found in the garage this morning, I'm going to try my little experiment on the way home this afternoon if I can reach it.

UPDATE:

I unplugged the hose going from the check valve to the firewall, it was black BTW, and put a plug on the valve. I fired her up and the RPMs when way up and then stalled. I started it again and it maintains a steady idle at about 750. I cleared the codes and drove to the Kroger and back. It was only a few miles but no SES light yet and I'm getting a "PD" (previously detected) P0171 and P0174.

I've got a 110 mile round trip commute, we'll see shat happens tomorrow.

The lean codes came back. However, it is running a little better, It seems to not be trying to stall as much, especially in reverse. Must be a leak somewhere else.

Tomorrow I'll take vacuum pressure readings on the intake itself and all the engine ports and see what I come up with. If those are all near 20in.-Hg I think I'm going to take it to a dealer service shop and have them locate the problem.

Glorious news!

I found the culprit. The vacuum hoses for the HVAC were disconnected from the connector on the firewall.

I also may have had the check valve on the vacuum reservior backwards. The black side goes towards the manifold, white side goes to reserv. and HVAC.

I haven't driven it very far yet but I have total control of my vents, cold air comes out the ceiling vents in the back!!! My kids are going to be very thankfull.

No codes, no stalls, purrs like a kitten.

It appears to be fixed!

Of course, I spoke too soon!

Lean codes came back. Vent control is sweet though.

I removed the vacuum tube serving the Fuel Pressure Regulator at the intake manifold and applied my meter there. I have a steady 12 in Hg. The manual says 17-22.

With that tube reconnected I took a reading at the fuel pressure regulator end and got 3 in Hg.

For fun I got out some new tubing and replaced that tube and took another reading. 8 in HG.

There is no vacuum at the EGR valve. There's a hiss at it and when I press down on the vacuum tube connector it stops.

I suspect all the vacuum tubing now, the connectors as well. I think I should replace them all and see what I get then.

Anyone know what size I should use?

:angryfire I found a cut in the hose on my vacuum meter.

I had left it on my work table in the basement, I think one of the little kids must have done it. I can't be sure if it was like that when I tested so it's back to the drawing board.

It looks like someone took one swipe at it with a saw. Fortunately it's near the end, I can trim it off, it will just be a little shorter.

See, this is why I can't have nice things. :mad:

With my now shorter pressure gauge, I re-tested the vacuum pressure. 19"

No pressure at the EGR, is that normal? Isn't there a filter in the EGR vacuum regulator? I can replace the tube and fittings if need be, too.

Fuel pressure is 26.5 at idle, below spec. which is 28. It's in range with key on, engine off and after five minutes. Pressure spikes if vacuum is removed from pressure regulator. Vacuum pressure at regulator: 19. I will put a new fuel filter on in the morning and see if that helps the pressure.

Oh, and there were new codes!!!

P1131 and P1151. I'm as far lean as the system can deal with.

Freakzilla, I don't know how many you have, but I have 30 curious, 8 year-old fingers on my BOYS!?! :banghead: Sigh...... :disappoinI truly know and feel your pain. They torture my stuff, dump it wherever they drag it, and then I'm the one who asks the questions. :nono: Their stuff is theirs and mine is theirs, too. Sigh.... :shakehead It's a real love, hate kind of arrangement. :crying: It never occurs to them to ask if it's alright to do whatever to whatever....sigh. If not now, you still being annoyed, it will be funny. :iceslolan
I had to chime in! :rofl:

You won't see any vacuum at the egr until the system calls for the egr to open. There shouldn't be any vacuum when at idle but will be at higher rpm. You could trace the egr vac line to the egr vacuum regulator(solenoid), evr, and check for vac at its supply side, or you could maybe skip trying to get to the evr and check the vac near the origination of the evr supply line at the intake manifold vacuum "tree", so you won't have to struggle to check it, though if there is a leak I guess you would want to check it at the evr.

The fuel pressure spike is normal with the vac line to the fpr off. Your two lean O2 codes will remain until you can get rid of your vac leak or other source of air getting into the system downstream of your MAF. These are new codes after all your old codes have been cleared, right?

Ya, I hear you both. I've got 13yr old, 11yr old and 7yr old fingers "helping" me with jobs. The thing I learned early is to (age appropriate) educate them on tools, care, danger etc. My son has to be the best with this and he's the 7yr old. You don't know how handy it is when I'm doing some job and can say to him "can you grab me a no 2 phillips screwdriver?" He's probably the best helper I have. So, I'd use the "helpers" as teachable moments.

-P

I like to say that god made them look like me so it's harder to kill them. I've got a step-son and three of my own, BTW.

Anyway...

Yes, I cleared the codes and went around the corner to the autozone and back and I got the 1131 and 1151 codes, I've never seen those before. I got a new EGR vacuum regulator just in case, but thanks for the info about it not turning on at idle. At this point another $25 is like a tear in the rain.

I think my real problem is the low fuel pressure, so I got a new filter and will get under there later today.

Anything else that might effect my fuel pressure besides a bad pump? I really don't want to drop the gas tank.

Yeh, your fuel pressure regulator. It could be keeping the pressure too low. To test that theory, it should go up to 40 psi or higher with the engine on and the vac line off. If so, and the pressure with the vac line on is too low, it could be the FPR. Another thing you could do to test that theory is to apply different amounts to the FPR while its running and watch the fuel pressure change. You will need to have a vac gauge in line too to see the vac amount to make a correlation. Your low pressure may be just the vacuum amount and not the FPR.

THe new fuel filter made an incredible difference, I didn't think it was that old. Fuel pressure is now 39 with the key on, engine off, 34 running at idle and 30 after off for five minues. So it's in spec as far as that is concerned now.

I put the new EGR vacuum regulator in anyway to make myself feel warm and fuzzy.

I cleared the codes with my scanner and went for a little drive last night and it runs like new. No stalls in reverse and the idle was very steady at around 750.

I still got the 0171 and 0173 codes but no SES light. Could it be that I need to disconnet the battery to get that to clear? Do I need the dealer to re-program the PCM?

I'd bet my firstborn that there's no vacuum leaks, I'm getting about 18" at the manifold and about 15"+ at the end of the vacuum lines from there. Is it normal to lose a little pressure through a line or should I get the same as at the manifold? It's within spec at the manifold and it seems those appliances only take a few inches of pressure to work.

Only other place I could imagine a vacuum leak would be at the manifold itself of the heads, but I torqued those down to spec in three stages, I'm pretty sure they're good. I guess I should do a smoke test to be sure.

The light came back on but I feel I'm a little closer.

Last night I was bored and decided to spray flammable liquids on my running internal combustion engine...

There seems to be a vacuum leak somewhere around the EGR. I don't think it is the vacuum port, it seems to be either the exhaust pipe that goes into the bottom or the connection to the lower intake manifold.

I didn't replace the EGR gasket when I rebuilt, now I feel like a dumbass. $2 at AZ. I bet that's the source of my lean code. Do I need an o-ring on that exhaust fitting? I don't remember one being there.

Replaced the vacuum tube to the EGR. Existing (green) tube had small radius bend at solenoid, hard to blow through. Now has more slack, reused connectors and harness.

One good thing about being a Windstar owner, there's always something to do on the weekend!

I had planned on doing pugs and wires anyway.

I am going to guess...and it is only a uneducated guess....but I would guess that the leak would be on the intake manifold side.
The pipe from the exhaust.....I would expect.....would be under pressure......
Of course.....I would check the code(s) to make sure that it is a lean code before thinking vaccum leak.
But a vaccum leak would be extra air getting INTO the intake......and a leak on the exhaust side of the EGR valve would still need the EGR valve to be open to detect.
HOWEVER....a leak in that pipe could mess up the readings for the DPFE......a leak at the EGR valve connection....you would have flow sensed (though not going into the intake) through the pipe, that the DPFE would sense.
This would give you some P04xx type code for improper EGR flow.

I tightened the bolts connecting the EGR to the manifold and that leak seems to be gone. I got a new gasket anyway, just in case.

I installed new plugs (Autolite DP) and wires, new 02 sensors on the exhaust, prior to catylytic converter. I thoroughly inspected my vacuum hoses, the brake booster hose needed a clamp at the manifold. All the other clamps are tight. I sprayed intake cleaner all over and can't find any leaks. There are no wistles or hisses. Vacuum pressure is in range at the manifold and all accessories. Idle is constant at ~750, no stalls, no stutters.

It's never ran better.

Still I get the P0171 and P0174 codes.

I'm going to check my fuel pressure when I get home from work, I just replaced the filter last week and pressure went from low to maxed. If it is a clogged fuel filter again, I think I must have something in my tank.

I wouldn't be suprised if my kids put candy in there or something.

Fuel pressure is low (31) with key on engine off, min. is 35.
At Idle it's 36 and after five minutes off it's 38, both in range.

Does this indicate a weak pump or some component thereof?