2000 Windstar not accelerating

Hello guys, My moms 2000 windstar with 84000 miles has started having problems, the mechanic has just rebuilt the transmission a week ago and I changed the oil, spark plugs and wires yesterday; my dad, my brother and I rebuilt the engine about 4.5 or 5 years ago because it overheated.

This morning the minivan was running fine, about 2 hours later of driving it, it wouldn't accelerate: the more you step on the gas the less it will accelerate. Since we were far from home we had to drive veeeeery slow... until we got home, during that time the CEL came on and I had it scanned the result is P0171 and P0174. I already read about the TSB regarding the intake manifold problem, my question is: Do these two codes necessarily mean I have to do the TSB? or can it be something else, like both oxygen sensors or a bad MAF?.

Thanks in advance for your help guys I really appreciate it.

EDIT:

The problem seems to be fixed by changing of the MAF sensor and the fuel pump, I would suggest to test the fuel pressure first just to make sure you don't waste money by buying both things, mine just dripped fuel when pressing the pin on the fuel test port instead of spraying it.

Normally a small vacuum leak at intake wouldn't cause this symptom.

But a very big vacuum leak or a bad MAF sensor can cause that. Cause the more you press on the gas, the more air enter in the engine. If the MAF doesn't meter all the air correctly, PCM will not give enough pulse to injector so they can't spray enough fuel, so the excess of oxygen reduces the power of engine since there's more compression w/o enough combustion.

Clogged injector and low fuel pressure can cause that too.

It doesn't sound like bad O2 sensor.

So first check if MAF tube's collar is properly tighten and air filter properly installed w/o leak. Then test MAF sensor operation with a multimeter.

Then finally test fuel pressure. See if the problem happen only at high engine temp or always.

Normally a small vacuum leak at intake wouldn't cause this symptom.

But a very big vacuum leak or a bad MAF sensor can cause that. Cause the more you press on the gas, the more air enter in the engine. If the MAF doesn't meter all the air correctly, PCM will not give enough pulse to injector so they can't spray enough fuel, so the excess of oxygen reduces the power of engine since there's more compression w/o enough combustion.

Clogged injector and low fuel pressure can cause that too.

It doesn't sound like bad O2 sensor.

So first check if MAF tube's collar is properly tighten and air filter properly installed w/o leak. Then test MAF sensor operation with a multimeter.

Then finally test fuel pressure. See if the problem happen only at high engine temp or always.

Hello thanks for your time and help. Actually as you mentioned the problem happens only at high engine temp, I started the engine this morning and revved it up and it works fine no problems. The air filter is OK I forgot to mention that I replaced it yesterday when the engine started to lack of power the old one was nearly dark gray in color and it was slightly smaller than the right one; the one I put fits tight in there it is the right size.

How should I check the MAF sensor and what pressure should I expect from the fuel pump?.

Thanks in advance for your help.

P.S. I already changed the fuel filter too.

To check the MAF sensor, you should ask Winswind or 12Ounce for pinout, since my service manual finish at 1998 model. Here's the procedure:

1) disconnect the MAF harness connector
2a) Measure resistance between signal and GND of MAF pins (should be limited)
2b) Mesure voltage between GND and B+ of MAF harness
3) Turn key to ON
4) You should have ~12.3V
5) Reconnect the MAF harness
6) With a metal needle, spear the signal and GND pins of harness and the measure the voltage at the 2 needles. You can also use needle probe for that.
7) Turn on engine, at 750rpm you should have 0.5-0.7V
8) Increase rpm up to 3500, it should increase to about 1.5-3V
9) The more you rev up, the more voltage should increase

Fuel pressure spec:
key on: 35-45psi
idle: 28-45 psi
engine off after 5 minutes: 30-40psi

Thanks again, I wonder if this is the pinout you were talking about:
MAF pinout (http://www.allfordmustangs.com/forums/attachments/v6-talk/24292d1172198458-need-wiring-diagram-maf-iat-6-pin-connector-2001maf.gif)

Also I found somebody else seems to have the same problem, it is quite weird to find someone else has the same problem at the same time! I will put attention in case he gets it fixed by changing the fuel pump.
http://www.automotiveforums.com/vbulletin/showthread.php?t=1023466

That's right. It's the good pinout for you van.

pin 1 is the signal
pin 2 is B+
pin 3 is GND

Hello again, I cleaned my MAF it seemed to be a bit dirty, after cleaning it the small wires were shiny again. I tested the fuel pump pressure and the result is.... 0 psi?. It is pretty weird but it's true, I was thinking that I might had connected the gauge the wrong way so I tested it on m lincoln town car with the same type of valve and it reads fine, so once again the fuel pressure on the windstar is 0 PSI, I pushed the small pin in the fuel valve to see if the fuel spray but it only drips out, there doesn't seems to be enough pressure to make the gauge to raise, however the van still starts and revs fine, I don't think it might be a blocked fuel filter since I already changed it. Is it actually possible to get this 0PSI reading and the van still starts?. Also when the van was running I noticed a humming sound, like a DC motor which seemed to be revving up, this sound lasted for about 1-2 minutes and then stopped. I tried to see where the sound was coming from but it could be heard from everywhere (the front, the back and even inside the van). Do you think the small filter inside the gas tank is blocked and that caused the humming?.

I have found that the catalytic converter is dripping, here are some pictures of it. Could this also cause the DTC's?. What else could this dripping cause?

Thanks for your help...

http://img805.imageshack.us/img805/8986/img00392201006291531.th.jpg (http://img805.imageshack.us/i/img00392201006291531.jpg/)
http://img180.imageshack.us/img180/3384/img00393201006291531.th.jpg (http://img180.imageshack.us/i/img00393201006291531.jpg/)
http://img14.imageshack.us/img14/3100/img00394201006291531.th.jpg (http://img14.imageshack.us/i/img00394201006291531.jpg/)

Normally it shouldn't start if there's no pressure. It requires a lot, a lot of fuel pressure to start a 3.8L engine. It's pretty misterious.

About the humming sound, maybe it's the motor of the fuel pump, I'm not sure.

About the water under the catalytic converter, it's not important. It's just condensation, probably a bad downstream O2 sensor that monitor catalytic efficiency. It doesn't affect engine performance, only monoxyde emission.

The fuel pump is supposed to run for 2-3 seconds when you first turn the key on, before you attempt to start the engine.

The fuel pressure (~40 psi) should be maintained for several minutes after the pump shuts off. If not (intially high but bleads dow quickly), there is a leak. The leak could be the check valve in the pump, an injector, or the fuel pressure regulator, or a hose leak. If it's never high to start, then the pump is bad, or there is a blockage. Logical places to look for blockage are the fuel filter and the inlet screen on the pump.

I think you should resolve the fuel pressure reading you're getting. This could be an indication to the cause of the symptoms that you see.

The fuel pump is supposed to run for 2-3 seconds when you first turn the key on, before you attempt to start the engine.

The fuel pressure (~40 psi) should be maintained for several minutes after the pump shuts off. If not (intially high but bleads dow quickly), there is a leak. The leak could be the check valve in the pump, an injector, or the fuel pressure regulator, or a hose leak. If it's never high to start, then the pump is bad, or there is a blockage. Logical places to look for blockage are the fuel filter and the inlet screen on the pump.

I think you should resolve the fuel pressure reading you're getting. This could be an indication to the cause of the symptoms that you see.

Thanks for your help, I will check everything later today or tomorrow morning. This morning I turned on the van and it works fine, I was maneuvering to make some space for the other car when I put the van in neutral and the started reving up, it was doing about 2000-2500 RPM's, could this indicate maybe a MAF problem? I haven't tested it yet, just cleaned it, I will test it soon.

There's one quicker way to see if the MAF is the problem.
Disconnect the MAF sensor harness and turn on your engine. Do a VERY short test drive. It'll run in default mode with the data of throttle sensor. If it run much better, the problem is the MAF (which I doubt). If it's worst, the problem is not the MAF.

Thanks for your help. I did what you said but it takes some random time for the van to start to "starve". I'll be changing the fuel pump tomorrow, since it is cheaper to replace it than the MAF I will give it a try, since the van has 84000 miles on it, it shouldn't hurt to change it; hopefully this will be the solution just like in this other thread:
Runs great... (http://www.automotiveforums.com/vbulletin/showthread.php?t=1023466)

I will post back the results ASAP.

I've just finished replacing the fuel pump after all day laying on my back under the van... LOL. I couldn't take it for a test drive but so far I can tell that the engine isn't as noisy as before with the old pump; could this be true?

Also the RPM's used to be higher about 1500-2000 RPM's more or less and now it's on the line of 1000 RPM's. I pushed the center pin on the fuel test port and the fuel actually sprays fuel unlike the dripping with the old pump. I will post back tomorrow with the test drive results.

Just to make sure: the P0171 and P0174 TSB shouldn't cause the van to stop accelerating like mine did, right?. I'm asking just to be sure that I don't need to take off all the upper part of the engine.

Best regards...

I've just finished replacing the fuel pump after all day laying on my back under the van... LOL. I couldn't take it for a test drive but so far I can tell that the engine isn't as noisy as before with the old pump; could this be true?

Yes, when I replaced my fuel pump, the engine become more quiet and more steady too. Because the fuel pressure is more constant. And it started more quickly and easily.

Normally, the RPM should be steady at 750 after idling 30sec or less, depanding of engine temperature. Or immediatly if the engine is enough hot. 1500-2000 was too much.

No the TSB 171 & 174 doesn't cause the van to stop accelerating. It can cause small lack of power, unstable idling (500-750rpm) under engine load (A/C compressor), small reduce in fuel economy. But it should still run fine with just this TSB.

Well you were right buddy, the van runs much better with the new fuel pump but after a few miles of driving the RPM's were behaving erratically and the van had a slight shaking while waiting at a red light with the gear on D, if I changed to N or P the RPM's would go all the way to 2000-2500 so I drove with the MAF disconnected and the engine ran a bit better I decided to buy the MAF for once and for all and the result is the van runs great now, the RPM's are just like you said in the line of 750 when idling. I guess I had a combination of both fuel pump and MAF going bad.

Thank you very much for your help serge_saati, hopefully this will be the last post regarding a problem in this thread.

P.S. I saw a kit for repairing holes in the whole exhaust system, do you think it would be good to fix the small hole in the catalytic converter?

You're welcome.

Yes, the exhaust repair kit would repair the leak in the catalytic converter. Just wait 2 hours after the repair before starting the engine again.

Just a quick question, could a bad bearing on the idler or tensor pulleys cause a rattling noise only when the van is on every gear but P or N?. Thanks.

No, it can't be a bad pulley or tensioner. Cause it would make a squeezing noise instead of rattle noise and it would happen whenever the load of engine since the torque of the pulleys doesn't increase with the torque of engine output.

It sounds to be a bad upper intake manifold (plenum). It's a common failure on the 3.8L engine. It's an inner baffle sound. It makes a sound similar to diesel engine, right? It should increase with the load/acceleration.

Hmm... Yes it has a diesel like sound and I was kinda aware about it was related to the intake only I didn't know which part, but there is another sound which happens only when the van is in R,D,1 or 2; maybe i'm using the wrong word to describe the sound since english is not my main language. I will record and upload it tomorrow so you can listen to it.

Do I have to replace the plenum to get rid of the diesel sound or is it enough to use some high temp sealant to fix in place the inner baffle in the manifold?.

Thanks again for your help, I really appreciate it.

No, replace the whole plenum (2 parts). Don't apply sealant. Cause if you do so, it will stick, and you'll not be able to remove it for future repair (i.e.: 171/174 TSB, lower manifold gasket...).

The other sound is like a metallic/high pitched noise?

Thanks again, I will leave the plenum repair for later, although it's a bit noisier than normal it doesn't bothers me at the moment but since I've replaced many things in less than a month it will seriously bother my pocket if you know what I mean. About the other sound it seems to be coming out from the steering pump, the sound can be heard for a brief moment when you put any gear other than P or N, stop at a red light or turn the steering wheel, I checked the oil and seems to be at the proper level, I will check back tomorrow when the engine is cold; in the meantime I have uploaded a video, you can listen to the sound in it:

Windstar weird sound (http://img517.imageshack.us/img517/9035/vid00002201007121948.mp4)

Thanks in advance for your help.

Ok, the low pitched rattle noise that we ear when you engage gear doesn't seem to be the Power Steering pump, cause it's not a metallic noise. Even if it's on this location. I think it's the timing chain, but I'm not sure. Are you sure it comes from the pump? Maybe you need a car stethoscope or a small tube to see precisely where the sound comes from. Low pitched sound are more difficult to find.

The other way to know is to remove the drive belt and run the engine. You will immediately know if it's the P/S pump or the chain. Then you can play with the pumps. But you should have the tool to put the belt back in place. I think you have.

I noticed also another small metallic sound in side of the pump at 0:36-0:38 of the video. So maybe you have 2 problems, not sure again. Your microphone is omni-directional?

The noise gets louder the closer I get to the P/S pump I will check with a small hose to make sure only I have to wait until the engine gets warm because the sound doesn't seems to appear with the engine cold, I was thinking on removing the belt too I will do it later today because right now I have to make a small trip. The other sound I don't know if maybe it's the cooling fan since I remember it was engaged while I was recording the video.

If the problem is the timing belt to sound should be more constant isn't it?.

The microphone is actually my cellphone, I shot the video with it.

Thanks for your help, I will post back ASAP...

I thought again about the noise, I'm pretty sure it's the P/S pump's bearing. Not the rotor's vanes of the pump. So you don't need to replace the pump, just rebuild it (replace the worn bearing).

Thanks again man, I didn't drive the van today because you mentioned the timing belt as a possible cause and I didn't want to take the risk to be left on the side of the road waiting for help, now that you are sure about the bearing I can tell you that you took a huge weight off my back, I will take the pump apart form the van, is rebuilding it a DIY job, is it hard or expensive?. I know it has some seals in it, will I need to buy these seals brand new or can I reuse the old ones.

I would like to know what pointed you to the bearing?; the fact of the noise being present only at warm temp? or what else?.

Thanks again man I really appreciate your help.

I know it's the bearings because I had a memory flashback, I remember a friend who had this problem a long time ago with a BMW and it was very similar noise. And you tell me it comes louder near this part.

Yes you need 4 new seals, cause the old ones can break when you remove them. If you never had rebuild a P/S pump, I recommend you to give it to someone who is specialized in remanufactured part (i.e.: NAPA, CarQuest...). They will charge you around 50$ + the bearing. Don't know how much is in pesos...
I never rebuild a P/S pump, but I know it's complex.

Serge_saati mentions a test that is very good.......remove the serpentine belt and see if the problem is still there.
NOTE....don't run the motor for more than a minute.....as you will have NOT coolant circulation.

Now.....if the noise is not there.....then you know that it is something on the serpentine belt line.......Alternator, water pump, power steering, tensioner pulley bearing......idler pulley bearing.
On my '96, I changed the power steering pump.......and the noise turned out to be the idler pulley bearing.
The idler pulley is right in between the alternator, power steering pump and the water pump.
I was SURE that it was the power steering pump......only made the noise above a certain RPM......not at idle......and I could not detect it by turning things by hand.
Years later.....I got a very similar noise......and it was the bearing on the tensioner pulley......I could tell by turning the pulley by hand......felt normal at first....but when I wiggled it and tried again.....I could clearly feel the problem.

Thanks to both of you guys I checked the idler and tensioner pulleys and replaced both because they felt a bit hard to rotate and the idler had a metallic noise so I guess the bearing was going bad and the tensioner pulley felt like it was clicking or something similar and it also had a metallic sound and at less than $20 dlls for both I decided to replace them, this had an immediate effect on the engine sound and I can even say that the van feels better.

Unfortunately the low pitched rattle noise is still present not as loud as before but still present, the next step will be to take a look at the steering pump, I did took the serpentine belt off and the noise goes away so definitely the problem comes from an accessory; I have to see how much it costs to rebuild the steering pump and compare the price with a remanufactured pump, if it's about the same I'll go with the reman pump; just one question: is it hard to remove the pump? is it enough to remove the belt and take the screws that hold the pump? . Thanks again for your help!

P.S. I forgot to ask, besides the van making the rattling sound, is there any danger to keep driving the van? something like the pulley coming out or something similar?. Thanks.

Good move on replacing the pulleys......remember.....if you feel some roughness or grinding/clicking when spinning them by hand.........it will be worse when the tension of the belt is pushing against it.

Power steering pump.......on my '96....I have pictures that show somewhat what I did.....
I removed the alternator........then......I removed the whole bracket that holds the power steering pump, idler pulley and alternator (if it were still there).......as 1 unit.
Use extra care with the metal line that connects to the pump....
You don't want to cross thread that.....and if you bend the metal line.....it will be tough to line up straight to start the nut.

Removing the alternator removes a lot of weight....and makes manovering the bracket and pump much easier.

Thanks for your help wiswind, I will do so within a few days right now I have to go and visit my family and don't want to spend the days fixing the van instead of being with my family. Do you think there will be any problem if I keep driving the van with that bad bearing? Is there any possibility for the pump to break down?. Thanks again for your help.

No there's no any dangers. It couldn't fail or anything, just make the disturbing noise.

When you will remove the pump, don't forget to bleed the fluid in a bottle after disconnecting the return line (rubber hose) of the pump.

To remove the high pressure line (metal tube), use a flare-nut wrench to disconnect it.
It's like that in my 98.

Ok thanks again for your help, being said so I will leave the pump like that for about two or three weeks, I've spent two much money, time and effort on it in the last month that I don't want to know anything about it to say the truth besides I'm going to visit my family and I don't want to waste precious time on cars.

Thank you very much to both of you guys for your help, I will let you know when the problem is fixed.

Best regards to both of you