Attempts stall, Idle Pulses 600-800 rpms, horrible MPG

[searcherrr]

Just got back from Pensacola (235 miles each way). Currently I'm getting 10mpg in town and 17 mpg on the highway and these figures are very accurate. I just took a trip and tested it. Overdrive is definitely getting utilized and besides the problem I've been trying to figure out (almost stalls/stumbles at ONLY hot idle when in park or in drive at idle when A/C is off after radiator fans turn off) the van drives like a dream and sounds just as it should (very smooth running) except when I turn off the A/C and the fans turn off.

All those items you mentioned in the previous post have been replaced. Every time whether its a shut off of the a/c or a/c off and fans turning off on their own it tries to stall the van. I guess we could call it a stumble and it picks itself right back up. YES, this only happens when full HOT. Never at cold.

I still don't like that I smelled even a "hint" and it was just a HINT of fuel for a split second and then gone from the FPR and I also don't like that when observing the fuel pressure while doing various testing that the psi remained 30psi and at one point dipped to 29 and eventually came back up to about 31.

I don't have an ampmeter. I have a multimeter..... Could I measure amps with that? or does that just measure volts?

I have tested ECT resistance and it checks out, however I have not tried pulling the ECT connector while its in use I don't think.

I am not sure I believe (unless someone can explain otherwise) the new fans are pulling too many amps. As I understand it the motors themselves pull the amps so why would i observe a higher than usual amp draw with the new fans? I could buy something being wrong with the harness setup, but again I'm really sick of dealing with this. The damn shop should've resolved this stuff and I got aggravated in May and didn't even bring it back to them. My stance right now is to just leave it be until I have more time and money to deal with it. Aside from the almost stalling or stumbling and the horrible MPG the van runs and sounds like a damn champ. Its just so smooth and a pleasure to drive. I just wish I could lick this damn MPG problem and the near stall issue.

I'm starting to think about replacing things randomly, but trying not to let myself.

Things that come to mind are the coil pack (It looks fine, but I've seen others say so did theirs and their pack was bad), the TPS, the crank or cam sensor, power steering pressure switch/sensor (if this vehicle has one), the FPR, the fuel pump and anything else i haven't replaced yet. Something I haven't replaced has GOT to be the issue.

Also wanted to note. After I redid the negative battery post wires and put in the new dropping resistor the "near stall or stumble" issue seemed to get WORSE! It would cause it to stall out more ..... um.... prominently.... for a lil bit longer and lower on the RPMs.

Lastly, I think I (we) need to entertain the idea that the near stall/stumble is not necessarily related to the radiator fans turning off, but somehow just a symptom of some other indirect issue. It could be the fan circuit etc.. but I want to entertain that possibility that its not related to the fans (IE: possibly fuel or some other electric somewhere).

[searcherrr]

On the Eve of what I'm calling Katrina Part 2 (Gustav) I thought I'd tackle this gas mileage problem perhaps 1 more time from a different perspective before I have to evacuate. All forecast models are concentrated with a bee line to Louisiana and as of 3AM CDT its forecast to be a Cat 3 or 4 at landfall and I would be within 75 miles of the eyewall on the worst side of the storm for its strength and tornado spawning.

Sooo...... I was wondering.... would it be stupid of me to go and replace the ignition coils or the TPS right before I pack up to leave? or would it in the long run possibly save me a bunch of gas since I'm getting a wonderful 10mpg in town traffic (which I'm sure to encounter a lot of in evac mode) and 17mpg on highway.

Approaching this differently from what I haven't replaced I figured is a better strategy because at this point there are lesser things I haven't replaced than the ones I have. lol

TPS - Throttle Position Sensor (Has yours ever gone bad?)
Crankshaft position sensor (Has yours ever gone bad?)
Camshaft position sensor (Has yours ever gone bad?)
Ignition coil (Has yours ever gone bad?)
Ignition control module (Has yours ever gone bad?)
O2 sensors are originals from at least 1 previously overheated cat; but no O2 codes
Used cleaned MAS (still looks good though; no codes) (Has yours ever gone bad?)
ECT (resistance tested out correctly) (Has yours ever gone bad?)
Intake Air Temperature sensor (resistance tested out correctly) (Has yours ever gone bad?)

Fuel pressure regulator (smelled a FAINT FAINT FAINT amount of fuel from it and you aren't supposed to; though FPR tests pass) (Has yours ever gone bad?)
Fuel Pump (to me its a weak pump, though shop doesn't agree even though I saw 29 - 30psi on the gauge) (Has yours ever gone bad?)

Alternator - though tests good multiple times, but could the regulator or rectifier be on its last leg causing anomalys that cause no codes and don't drain the battery? If so I've never known another alternator like that.

Odd problems that may or may not be related
-Window washer push-in button requires just the right push to get it to work
-NEW rear window opener buttons work in REVERSE:
--Pushing up on right switch opens right side rear window; push down closes
--Pushing down on left switch opens left side rear window; push up closes

Does this window switch thingy perhaps tell me there are some grounds crossed somewhere
or did my new switch just come made in the reverse?

Starting with the easiest parts to replace (TPS, IC, ICM, FPR, ECT) would ya'll at this point just start replacing items and SEE what happens?

[tripletdaddy]

Have you considered this hurricane maybe a blessing in disguise? If you have comprehensive insurance coverage, inocently park it in a flood zone and cut your losses! Then you can start with a fresh new van with its own set of problems!?! You may be better off!!!

Ok, ok. On many of the things you mentioned on this fan stumble business and bad mpg, I just don't know how to procede. If you have all new plugs, wires, whatever and no codes, I'd wait on the coil. I don't know 100% if it has an icm or if that is part of the pcm, but it makes you wonder about the two. If it does, I thought that it could cause mpg problems. At a parked idle, does it ever have sooty exhaust?

On the electrical issue, I'd make sure the battery and alt are strong, which I think you've done. Does the alt light ever flicker? So my next suggestion would be to be sure you have clean and tight grounds for the fans, the body, block, ignition. A bad ground to the fans will cause a voltage drop and spike and a current surge to the fans. I wonder if the shielding for interference for the ignition isn't right, though that might code too.

I doubt changing the ect would help the electrical issue, but if it's values are off it could affect mpg. It's cheap and easy to replace. Be sure to buy a brass and not a plastic one, but if you are confident in what you measured to be ok, then don't bother. A trick or test of a sort to see if the ect has any influence on your fan maybe, is to with a warm engine, pull the connector to the ect causing the fans to come on and then reattach it causing the fans to go off, as long as the engine isn't too hot to need the fans on at that moment. If the problem still exits, I'd think that would rule out the ect, which I doubt anyway would be the culprit, as it only sends a signal to the pcm and the pcm sends a message to the ccrm to turn on the fans.

On the same line of thinking, the iat may be worth testing, as it too affects fuel, egr, etc.

You may be able to measure current with your meter, but usually very little fused. Often in a different jack you can measure more, but unfused.

I'd think if you have a problem with the FPR, you would more than once be able to smell gas. I assume you are smelling the vac line to it, which if there is a leak, would suck it up, so that you could smell it and if enough, cause some surging or emission code, which you aren't.

I can't offer anything on your list of parts going bad as none have. Have you searched for bad mpg and fuel? I've had fp issues, but none that cause mpg problems.

I have the same problem getting the ww fluid to come on too. Sounds like the new window switch is backwards. Any chance the wires were swapped putting the connector on? You may be able to release the two wire pins inside the connector and swap them. The switch simply alternates polarity to the window motor, but the input or output is reversed.



I still think you should consider the flood and insurance angle. Good luck man. You and the rest of you down there will need it!

[12Ounce]

Mine's a '99 so things will be different. But some early failures for me included: IAT valve, Camshaft pos sensor, and the DPFE sensor. Later (150 kmiles or so) I also lost the camshaft synchronizer and the fuel pump, .... and of course, the intake manifold thingy more than once. The coil got replaced at about 200kmiles ... but it was because of a wrong diagnosis.

The crankshaft sensor and the Throttle Pos Sensor are still original at 240k miles.

Good luck dealing with the big bad blow!

BTW, 10 mpg for pure city driving ain't bad, I get less I'm sure.

[searcherrr]

Originally Posted by tripletdaddy

Have you considered this hurricane maybe a blessing in disguise? If you have comprehensive insurance coverage, inocently park it in a flood zone and cut your losses! Then you can start with a fresh new van with its own set of problems!?! You may be better off!!!

LOL - Unfortunately I gotta take the van if I want to keep anything of mine. but it was good to read something funny.

Thanks for your other suggestions.

12Ounce - Can anyone else confirm getting 10mpg in town? I can't believe that could be true and LEGIT or OK??????? If this is the way it really is can some others let me know? I thought everyone was getting better than that city/hwy? cause if people are not then I'm just wasting my time on nothing.

[12Ounce]

I use the on-board calculator. If I reset this thing and do several miles locked down in city, stop-and-go driving ... I've seen readings as low as 8mpg. Of course, purely on the highway I want to see mid-twenties and better. But if there is a mixture of highway driving and a good bit of town driving ... the "high teens" is all I hope to get.

[tripletdaddy]

17 does sound low for highway. At least 20 or more would be expected. On long trips, I may get 25, but that's if it's flat, no slow downs and cc all the time. That's also with a somewhat loaded van. I don't do city driving, so don't know there. Are you heavy footed with the gas and brake? That will suck down your mpg.

[wiswind]

I have not been on for a couple of days....but cannot offer much advice anyhow.
This is a super difficult problem to track down.
The ICM is a part of the PCM on the older (most likely newer also) windstars.

17mpg sounds a bit low.......city mileage can be anyone's guess.....some folks spend more time sitting idling in traffic....creeping forward a few feet every few seconds.....and those folks are going to see pitiful mileage.

I would also expect 20-24mpg from this vehicle.
Problem is.....3-4mpg is a tough problem to track down.....as it indicates "sort of" a problem......but not a serious problem.
Tire inflation.....brake dragging....etc can easily rob a few mpg's from you.

I also hate to tell you to throw parts at it to try to fix the problem.....as you have already replaced so much.
Some things are "tune up" items......air/fuel filters and such.....so this is where I normaly start.
The stumble seems like the PCM is seeing something it should not......or not seeing something it should.
With no codes......it is a crap shoot.
Although fuel pressure and fuel flow are NOT monitored at all by the PCM.....which puts that on the list.
But a fuel pump is pricey.....in the cost of the unit....as well as the cost of the installation (gotta drop the fuel tank).
How a fuel pump would cause a stumble only when the fans turn OFF is beyond me......

I would re-check all the power and ground connections.......remember that these were messed with during the engine replacement process.
It is super easy to miss a connection......or break/damage a wire or connector.

[searcherrr]

THIS POST #129 IS TO SERVE AS A THREAD SUMMARY AND NEW START:

Problem remains:
Near stalling only at HOT idle and also HOT running while in DRIVE and vehicle stopped as soon as cooling fans turn OFF. Problem seems slightly worse than a few months ago. Has been driven now roughly 2000 miles on new engine.

Isolated behavior:
KEY NOTE: Unplugging the cooling fans ELIMINATES the near stalling effect at ANY engine temperature WITH or WITHOUT the A/C on. Allowed temp to get up to "R" on the temp gauge briefly to ensure it still didn't try to stall while fans were unplugged. Does not try to stall COLD or HOT with cooling fans unplugged when A/C cycled on/off.

Things replaced/tried/investigated:
1. CCRM
2. Both cooling fans; Old ones worked fine; New ones on and same problem.
3. Radiator Fan dropping resistor
4. ECT checks good in low and high temps
5. Alternator is fine; tested many ways; tests good.
6. Grounds at front of vehicle & at alternator checkout. Haven't checked grounds elsewhere (IE: At firewall side of engine bay)

Ongoing Theories:
1. Back-EMF from cooling fans
2. Back-EMF from ac clutch coil?
3. List of things not replaced in post #122.

Possible back-emf paths to the PCM:
1. Fuse W (10A in engine fuse box) to Pin 4 at PCM
2. CCRM (replaced)
3. FANS - Selectron had said that back-emf protection was not shown in the diagrams he looked up at the time, but that a reverse-biased diode was likely built-in to the fans themselves and that even if the diode onboard the fans failed he wasn't sure back-emf/voltage spike could get past the fans without destroying them.

Proceeding:
I've msg'ed Selectron (anyone else contribute if you can/want too) about proceeding with the back-emf theory and hopefully we can discuss how to put in a reverse biased diode to test back-emf coming from the fans. Though what I do not understand is that with the fans unplugged the problem goes away, which is good, but I have NEW fans now so it would seem that something is being missed.

Given that I have new fans, if the diagrams only show paths of the CCRM and Fuse W as possible paths to get back to the PCM with back-emf, then does this mean that the problem MUST BE a bad GROUND SOMEWHERE?

Would an EMF reading device help me at all in this matter?


New problem surfaced (may or may not be related):
Smell Radiator fluid inside and outside when 1st use of heater a few days ago. Coolant reservoir emptied completely when using heater for 1st time since February. Thread: http://www.automotiveforums.com/vbul...87#post5849387

[searcherrr]

While looking for a new coolant leak tonight I discovered 2 or 3 mini vac hoses at a vac junction that were 75% pushed onto their spouts. I pushed them in the additional 25%. AIR LEAKS THERE? Who knows.

More interesting. UNMETERED AIR? - There is a dent and/or "POSSIBLE CRACK" in the center section air intake pipe pretty close to where the pipe could hit something that looks exhaust or DPFE related. Someone working on my van must've leaned on the air intake pipe as if it were a table to cause such a dent or "possible crack" in that hard plastic material. I didn't have time to remove the center section air intake pipe, but I rolled some clear duck tape all the way around it and over this spot. If air was leaking there I'm hoping it'll just suck inward of the tape and seal the leak and MY GAWD COULD THIS BE THE END OF THIS GHOSTLY NEAR STALLING AT IDLE/DRIVE-WHILE-STOPPED?

I will not know for sure until I fix my new and so wonderful coolant leak coming from the NEW FORD OEM radiator cap.

[searcherrr]

If there was unmetered air at the dent/crack in the air intake middle pipe it didn't fix a damn thing to cover it up. Still tries to stall ONLY after rad fans turn off.

I think I'm gonna get creative here. I'm gonna run the van for 30 - 45 minutes without the radiator fans connected. Gonna get a big fan and put it right in front of the radiator (or 2 big fans if needed) to keep it cool once it goes just above the "M" on the temp meter. What I am attempting to do is more than rule out that the engine doesn't try to stall when the radiator fans are not in play at all.

Thats my project till Selectron can get back on here and help me with this diode idea he had.

[searcherrr]

I was thinking about this again (especially since it seems Selectron gave up on me; lol) and I'm not really feelin the back-emf thing now. Here's why:

1. The other day I revved the engine to 1000-1300 RPMs and held it steady as the radiator fans were on. I held the RPMs in that range until the fans cut off (when I should be expecting the back-emf; at fan turn off) and when the fans cut off the engine DID NOT TRY TO STALL like it does when its idle or in drive at a stop.

If this was a back-emf issue from the fans it would not pick and choose when it delivers this back-emf, it would ALWAYS deliver the back-emf regardless.

2. Both fans are new. If this was a back-emf issue from the fans it would've been solved when installing new fans (or very likely so).

New thoughts:
I do not believe I have an electrical issue now cause the back-emf should occur at all times regardless of RPMs and should even try to stall the van while in motion as the radiator fans are cutting off which would normally be during low speed stop-n-go traffic. I think either air/fuel is getting cut off or slowed enough that when the cooling fans turn off, proper idle cannot be maintained and that this "halfway" reset/restart (near stall) of the engine is causing random electrical problems upon getting back up to speed. Previous electrical problems include: Broken MAS element wire and PCM fried.

FACT: This only happens at idle (in park or in drive)tells me there is a problem maintaining the subtle balance between air/fuel required to hold idle speed.

FACT: The RPMs needle constantly hunts up and down within about 100rpms even when there is no load running against the engine.

FACT: Giving the engine enough gas to hold idle over 900 RPMs while the fans cut off keeps the almost-stalling from happening every time.

FACT: Almost stalling does not occur until after the fans have turned off at least 1 time.


New Action Plan:
I believe I'm going to start replacing the most relevant suspects and see what happens. I didn't want to, but I'm tired of it being like this. I'm going to go in the order of the following list:

1. Remove cowl and Inspect for vacuum leaks. I've never wanted to remove the cowl. Uggh.

2. While cowl is off - Inspect for bad grounds.

3. FPR - ORDERING TONIGHT - The FPR is in constant motion, helps control idle speed and fuel flow, may have melted/damaged internal rubber parts due to previous engine overheat, but not damaged too bad to where it can't work at all. I also have smelled a FAINT amount of fuel from the FPR's spout when removing the vac line and you are not supposed to smell ANY FUEL at all when doing this, but I was never sure if it was supposed to be a very strong smell or just barely a fuel smell or what.

4. TPS - Original and in nearly constant motion; wear item

5. IAC - I have a new one installed, but I'm gonna try another one (swap in) and take it back if the problem is still there.

6. Ignition COILS - (will remove and inspect closely first; if look good may skip it)

7. ICM

8. Camshaft position sensor

9. Crankshaft position sensor


The bottom of the list:
10. MAS - Used/New cleaned MAS is installed. Still looks good; no codes. May clean again and swap in another to see, but this is a doubtful cause to me at this point.
11. O2 sensors; though no codes; are originals from at least 1 previously overheated cat

12. Fuel Pump - Will retest, but to me it is a weak pump, though shop doesn't agree.

13. Alternator - Though multiple tests show it as good if I haven't resolved this problem by this bullet #13, there will be extremely little left to look into. Maybe the regulator or rectifier could be on its last leg causing anomalys that cause no codes and don't drain the battery? If so I've never known another alternator like that.

[searcherrr]

I intended to do the #3 FPR with #1 and #2, but of course I just did the FPR cause it was easiest.

Tests done with new FPR in.

Result: No change in engine behavior, unless 1lb less of fuel pressure resulted.

Detailed Results:
1. When I connected the fuel pressure test gauge (with relief valve button) to the test port there was absolutely ZERO residual spray of fuel. ALL other times that I have tested the FUEL pressure there's always been spray. The gauge showed "NO FUEL PRESSURE". It was just absent completely and this is after the engine had sat for over a day or so in about 40 - 60 degrees overnight temperatures for a couple days. Since its gotten cold outside maybe this resulted in this test result of no pressure. I found it suspect thugh.

2. Results of fuel psi testing are as follows related to the procedures listed below:
a.1. Flick ignition on/off several times - Pressure remained at 28-30psi (barely making it to 30psi; more like 29psi)
b.2. Remove vac line from FPR - Pressure remained at 38psi
c.3.a. Idle PSI = 27 - 29psi
c.3.b. 2500rpms for 1 full minute = 27 - 29psi

3. NOTE: 9 months ago when I tested fuel psi the lowest I got was 28psi. Since then and about 1500 - 2000 miles of driving its gone down 1psi.

For reference sake to go with results above:
Fuel Pressure Regulator and Fuel Pump Test - Gauge connected to test port for all tests

At engine off; ignition ON position
1. Flick ignition on and off several times to verify pressure remains constant
Should be between 30-45 psi (210-310 kPa) (Ford service manual)
If not then bad fuel pump or clogged fuel filter

At engine ON; ignition ON
2. Remove vacuum line from FPR
Gauge should increase 5 to 12 psi (Ford service manual)
If not then bad regulator; replace

At engine ON; ignition ON
3. Increase engine speed to 2500 rpm and maintain for one full minute.
Record fuel pressure.
Should be between 30-45 psi (210-310 kPa) (Ford service manual)
If not then bad fuel pump or clogged fuel filter


Question: Until I resolve this matter could I simply run with the FPR vac line disconnected so that my FUEL PSI is in spec range? Should hurt anything huh?

New idea for test: If the fuel pump is "going bad", but I get 38 psi at fpr vac line disconnect then if I am right about my near stalling being the fuel pump shouldn't this "near stall sputter; dip below 750rpms" cease if I left the vac line off the fpr for 10 - 15 minutes while at full hot?

New idea for test: If I can rig something up I'd like to test the PSI before the fuel filter and after the fuel pump. This I think would help me rule out a clogged fuel filter (which mine is new as of 9000 miles ago) as I have not been able to remove the one that is on there now.

Executive Decision: After over 1 year of living with this problem I have decided that my fuel pump is "bad/going bad" and has been in this state for a very long time and likely the only reason it hasn't died yet is because of my repeated use of B-12 Chemtool. I am going to get 2 other mechanic's/shop's opinion (other than my trusted shop who told me the fuel pump was probably ok despite my test results). I have simply decided to embrace and believe the Ford CD manual's documentation. I mean they didn't write it for their health. I will do the last easy "FPR vac line removed" test and see if the engine tries to stall or not in that condition as I had not paid attention to this before because every time I'd removed it before it was just momentarily to test the FPR's function.

[searcherrr]

Items done thus far are IN BOLD according to new ACTION PLAN above:

1. Remove cowl and Inspect for vacuum leaks. I've never wanted to remove the cowl. Uggh.

2. While cowl is off - Inspect for bad grounds.

3. FPR

4. TPS - Original and in nearly constant motion; wear item

5. IAC - I have a new one installed, but I'm gonna try another one (swap in) and take it back if the problem is still there.

6. Ignition COILS - (Old ones test out fine, but NEW lower resistance Accel coils installed anyway.)

7. ICM

8. Camshaft position sensor w/ New Synchro

9. Crankshaft position sensor


The bottom of the list:
10. MAS - Used/New cleaned MAS is installed. Still looks good; no codes. May clean again and swap in another to see, but this is a doubtful cause to me at this point.

11. O2 sensors; though no codes; are originals from at least 1 previously overheated cat

12. Fuel Pump - Having shop replace it today. I want to see the FUEL PSI within factory specs no matter what anyone has told me that they don't think its bad. Furthermore the tank is very likely dirty since I had a clogged filter recently.

13. Alternator - Though multiple tests show it as good if I haven't resolved this problem by this bullet #13, there will be extremely little left to look into. Maybe the regulator or rectifier could be on its last leg causing anomalys that cause no codes and don't drain the battery? If so I've never known another alternator like that.

[uzzo2]

My vote is still for the RPG through the back window
Don't dread taking off the cowl, it's a lot easier than it looks, i can have mine off in about 15 minutes. Take off the windshield wipers and the antenna, several screws, then unplug the wiper motor and just pull it all out together, easy cheezy, good luck!