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

[Selectron]

If the near-stalling coincides precisely with the radiator cooling fans switching off, then I think you may have a problem with back-emf. Back-emf (electromotive force) is the phenomenon commonly known as a voltage spike, which occurs when the current to an inductive load is switched off. Even with a supply voltage of only 12V, this spike can easily reach hundreds, even thousands, of volts.

The spike is negative-going, meaning that it will have the opposite polarity to the supply voltage, and its duration will be very brief - typically just a few milliseconds. Because of its short duration you wouldn't see it on a multimeter, aside from maybe a momentary fluctuation in the meter reading, but it's observable on an oscilloscope, and with a digital storage 'scope it's possible to capture the waveform and analyse it at one's leisure.

There is a path from the positive terminals of the fans, through fuse 'W' (10A, engine compartment fuse box) and into the PCM on pin 4 (Fan Monitor Input), so a spike could be reaching the PCM via that route.

There's also a path from the coils of three relays within the CCRM - the EDF, HEDF1 and HEDF2 relays - into the PCM on pin 17 (High Fan Control), so a spike could be reaching the PCM via that route also.

The back-emf protection for the three (inductive) relay coils within the CCRM is clear to see - they're protected by a single reverse-biased diode, so if that has failed then for sure a spike would reach the PCM.

The back-emf protection within the fans isn't shown. They will likely be brushless DC motors, having a series of (inductive) coils fed via a solid-state current-switching circuit. Each coil will be protected locally by a reverse-biased diode, but in the event of a failure of one of those diodes, I don't know what the chances are of the resulting spike escaping from the motor. The circuitry will be relatively complex - solid-state current switching, current amplifiers etc., and I don't know if a spike could get past them without destroying them in the process.

Faced with this situation, I'd probably just open up the CCRM and check out the diode. It won't have failed short-circuit (if it had, it would interfere with relay operation) but it could have failed open-circuit or the soldering could be dry-jointed (cold joint). PCB track damage would be a less likely possibility too.

If the CCRM had awkward access or looked like it would be a problem to open, then I'd temporarily fit a reverse-biased diode externally.

If the vehicle still nearly stalled when the cooling fans switched off, then I'd remove that temporary diode from the CCRM and temporarily fit a reverse-biased diode across the fan motors - they're wired in parallel, so a single diode would protect against back-emf from either, or from both.

It's possible that you don't have a problem with spikes at fan switch-off, but if the voltage feed into the fans, and the ground path leading from the fans are both good, then that's what I would be looking at next.

I won't go into detail on hooking up the diodes because this post is long enough already, but if you want to proceed with that at any time then let me know and I'll explain more fully. The diodes required would be cheap, and readily-available types.

[searcherrr]

Originally Posted by wiswind

If you DO smell gasoline at the fuel pressure regulator....then it needs to be replaced.
However.....it can be tough to tell if you really smelled fuel at that point or not.
It WOULD explain a lot if it is leaking....but this would be the first time that I have seen it mentioned (not that it cannot or does not happen).

Well what I did was pull the vac line from the intake manifold and put it directly under my nose while the engine was running while I was plugging the intake manifold with my finger. I smelled it only once and it was definitely gasoline smell, but it was faint and only there for maybe 1-2 seconds. Also, engine wasn't at full temp yet either.

I was just thinking about it though - there's a diagram of the fpr in the cd-rom I have and its very clear that fuel and vac are supposed to be separate so I shouldn't have even smelled a hint of fuel however I really don't see how thats possible that the seal would be 100%. It seems like as the diaphragm slides up and down you would smell "some" small margin of fuel here, but so far no one else has said that and I'm probably looking too far into this. Its probably just bad and may have gone bad when the engine overheated above the "H" mark in October. So it would be rare in NORMAL situations for it to go bad, but in an abnormal situation where the engine got that hot it may have melted the rubber internals (assuming the diaphragm is rubber).

[searcherrr]

Originally Posted by tripletdaddy

Searcherr, I don't think I can add much more than what others have brought up. No battery/alt light come one any? <<..rest truncated..>>

NO battery or alt light at all.

I still plan (once exhaust setup is back together; now hopefully Monday) to do the voltage tests Selectron recommends. Thanks for the thoughts about the alternator. I honestly don't know how the brushes could still be in good condition after 158k miles. Do these brushes actually rub on something that turns? I seem to recall the words "rotor" or "stator"????

[searcherrr]

Originally Posted by 12Ounce

Instead of "anti-sieze", perhaps better wording would be "thread-loc". It was the original manufacturer's installation. You know, the bolts that come with the blue stuff on the threads.

That makes more sense.... still like you observed it reduces current flow.

[12Ounce]

What have you done relating to the engine temp sensor?

[searcherrr]

Originally Posted by Selectron

If the near-stalling coincides precisely with the radiator cooling fans switching off, then I think you may have a problem with back-emf. Back-emf (electromotive force) is the phenomenon commonly known as a voltage spike, which occurs when the current to an inductive load is switched off. Even with a supply voltage of only 12V, this spike can easily reach hundreds, even thousands, of volts. ......

Selectron - WOW. You make me feel good about how much I write. I really appreciate this in depth analysis because YES it is PRECISELY when the low-speed cooling fan(s) turn(s) OFF EVERY SINGLE TIME. It does not do this at all when cold or warming up to operating temp - ONLY AT OPERATING temp after low speed fan(s) turn(s) OFF.

I like your diode idea, but I'm just not gonna drive the vehicle till I've figured this out. I may be interested in doing the diode later though if I run into delay getting the parts I need.

Lets assume for the moment the problem IS a back-emf/voltage spike caused from the fans turning off. If I just replaced the CCRM and fuse W (10A) would that likely take care of the problem and in addition that the back-emf could be coming from the fan motor(s) itself/themselves which may mean replacing the motor assembly?

I think once I am able to test for the voltage spike I'll use alligator clamps and keep my eyes peeled on the multimeter for the voltage.

Is a 10A fuse either BAD or GOOD or can it be "going bad"?

However, would this back-emf explain 9 - 11 MPG? It doesn't seem like it would huh? This is what makes me still concerned about the FPR and of course again the CCRM since the fuel pump relay is in there in addition to the fan relay.

If I look at the old CCRM what am I really looking for to know its relays went bad? Whats a PCB? Whats dry jointing or cold joint? What do these things look like in non-electrical terms? hehe

Lastly, I know this is going to sound "SUPER-NERD", but I've always wanted an oscilloscope. lol - There've been several situations on my car where I could've used it for testing against spec waveform data in the manual.

[searcherrr]

Originally Posted by 12Ounce

What have you done relating to the engine temp sensor?

If thats the same as the engine coolant temperature sensor I've cleaned its connectors and verified resistance at its ground wire. I've done nothing else with it yet.

[tripletdaddy]

I will just throw this out there. Is there a way for you to have your PCM checked besides $100 at the dealer? I accidentally cooked the PCM on my Taurus, 3.8L (same as Winnie) and it ran like crap, nearly stalling, running rich enough to spit black out the exhaust. The car will also run this way when putting in a new PCM while it's relearning how to run the engine, as I had done. Eventually it will smooth out. Searcherr and others, maybe yours is not "learning" and retaining what it experiences so it continues to use the same original crappy parameters. The PCM on mine took 5 to 10 minutes maybe to show improvement, high idle helped a lot, driving it for 15 minutes did a lot to smooth it out. I'd expect the same for your's to relearn. Another thought regarding this PCM business that I learned was the compatability of the PCM and engine is supposedly very critical when I was trying to find a used replacement for mine. Could your engine and PCM (EEC, ECU, ECM, ECA, engine computer, etc.) not be properly matched? At this point, confirming compatability wouldn't be hard to check and maybe worthwhile. Unfortunately, you may need to get the exact PCM number off the Ford part decale which was only visible with it pulled out for mine, but maybe going by VIN would avoid that issue. A bad pcm may explain the things that aren't working out like they should. Could your first reman engine screwed up your pcm if not the right match? Can the shop that did your swap read/check your pcm as part of the same job?

[searcherrr]

The shop replaced the PCM prior to the engine overheat/failure in October with a brand new Ford OEM. The very next day after the PCM was replaced the MAS blew its element wire on my way out of there.

I trust that they put in the right PCM and I was not having bad MPG with the old engine using the new PCM prior to its failure. Thinking back this issue always existed prior to new engine install. It was just much much less noticeable and I always attributed it to "old engine" and it didn't try to stall the vehicle like it does now and I never noticed back then that it was only when the low speed fans turned OFF. Back then I didn't know my dropping resistor was corroding and falling apart either and lots of other old components that had "worn together" were in play in a system that aged with a balance over time.

Now I have a hodge podge mix of old and new components with very few old ones left. My guess is the new stuff is much more sensitive to whatever was causing this issue when it was all old stuff. After replacing the dropping resistor and recrimping the grounds at the battery it makes sense to me now that this problem got worse cause the electrical is now better grounded for transmitting current during the theorized voltage spike after the fans turn off.

If I'm not careful I'll end up blowing my new PCM unless this really is related to the fuel system and not electrical...... could be both and 2 separate (though contributing to the symptoms) problems.

[searcherrr]

FYI - Cold testing of ECT and IAT resistance:

ECT: 25.35
IAT: 24.96-25.26

Both tests done at 87 to 86 F

I found some spec data and that appears to be accurate for both.

I can't do a hot test till I can run the van for an extended period, but I doubt I will find either sensor is bad.

[searcherrr]

Voltage tests with zero load:

1. Cold battery after sitting for 24 hours - 12.37v - It actually was 24 hours with the cables connected before the next 2 days it was sitting with the neg cable pulled off.

2. Idle voltage - 14.68v

3. 2000 rpms rev voltage - 14.70v

4. Voltage spike test - Can't do yet. Taking exhaust pipe in tomorrow.

Is that too high or just right for an alternator?

[tripletdaddy]

Those sound like ideal voltages from your charging system. The alternator brushes do actually contact and ride on the commutator part of the armature, which is what is spun past the stationary field coils of the alternator. So, yes the brushes wear down, and if you have an externally mounted voltage regulator, you can replace the brushes, if they are short, as an entire assembly with the volt reg, or just the brushes alone. Either way, you will most likely need to pull the alt to do that, and I would go ahead and have it bench tested so your rectifier, diodes, reg and output can be checked and help you to decide what level orf repair to do.

What I meant on the PCM issue is to be sure that the new engine is a match to your old PCM.

I may have to leave your theory to Selectron on the idea of better conductivity and grounding with voltage spikes resulting in greater sensitivity and worse results. I would be more in favor of a better outcome than worse with the said improvements, at the very least more accurate sensor data going to and from the PCM. Certainly poor conductivity to and from the pcm will create biased data and feedback. Tracing and understanding voltage spikes and eliminating them through design is out of my league and I would have to defer to Selectron on that. Voltage spiking from the fans turning off makes me wonder about the control relay involved drawing excess current due to bad contacts or weak pull in coil in the ccrm.

I was going to suggest doing a vacuum hold test on your fuel pump regulator. No leak down, no internal fuel leak.

[searcherrr]

I was thinking (kinda been obsessing over this crap) about it again and there are many symptoms that to me say the CCRM is toast:

1. My A/C clutch did switch on and off quite often prior to breaking open the system (freon recharge at new engine install etc..) and still does so fairly fast in my opinion now. CCRM controls this too - (As Wiswind has pointed out several times - lol).

2. The cooling fan turning OFF causes almost stall condition every single time and this is directly controlled by and routed through the CCRM (As Wiswind has pointed out several times - double lol) while all known grounds check out.

3. Fuel pump is directly controlled by the CCRM from the PCM (As Wiswind has pointed out several times - triple lol). To me, this could have a direct impact on fuel economy.

4. Maybe i'm wrong on this one, but since I have improved the ground points and system continuity it makes sense to me that this problem seems worse now because the source of the prob is getting through the electricals easier.

I have been studying the electrical diagrams and ground locations all AM hours of the night from the cd-rom I have as well as looking up fpr info and fuel test gauges to buy. I really have tested all "related" grounds, but 1 which is located underneath the battery. There really aren't as many grounds on the vehicle as I thought there may be, but there are many things routing into the grounds that are there and thankfully this seems to have been done in an organized manner.

So without further adue I'm going to take apart the battery area today, test that ground under there and pull the CCRM and have a look at it. I really don't know what I'm gonna see, but I was wondering if I could just clean the CCRM with electronic parts cleaner??? ... and reinstall it after drying and see what it does???

I know the new one is better, but its also $94. I wonder if I could just get one from a junk yard from a 2003 Windstar. It should be the newer one and maybe cheaper and still good to go cause its the revised version.

Thanks again for everyone helping and keeping up. Hoping to hear back from Selectron on my questions to him soon.

[wiswind]

2003 does NOT have a CCRM.....they moved the relays into the power distribution box.
You need to use the CCRM that is listed for your vehicle and year.
As far as "Junk yard", you might try ebay.....but....again make SURE that it is the correct one for your year, vehicle, and engine.

I do not know that you can clean the CCRM......relays inside a metal box.
I would not take the box apart.....as it would likely cause more damage than help.

When you said something about a wire at the MAF "blew off".....do you mean that it was burned/charred?.....if so....this could have damaged the MAF and / or the PCM.......

[Selectron]

Originally Posted by searcherrr

Lets assume for the moment the problem IS a back-emf/voltage spike caused from the fans turning off. If I just replaced the CCRM and fuse W (10A) would that likely take care of the problem and in addition that the back-emf could be coming from the fan motor(s) itself/themselves which may mean replacing the motor assembly?

Yep, that's about right but the problem is that if you do have a spike at switch-off then there are two possible and quite separate sources and you wouldn't know which one was causing it, so you wouldn't know which one to replace. In the absence of a 'scope the only relatively easy way to determine the source would be by temporarily adding spike suppression to each in turn, in the form of a reverse-biased diode, and finding it by a process of elimination. That's not a difficult task, but if you're unaccustomed to working at component level then I probably wouldn't recommend it because there's the possibility of hooking things up incorrectly, and compounding your existing problems.

Similarly with the CCRM - I wouldn't recommend even attempting to open it if you're not experienced at that level because the chances of it going smoothly first time would be pretty slim.

Fuse W won't be implicated in any of this, and you can assume that it's healthy, because it feeds 12V back into pin 4 of the PCM (Fan Monitor Input) to inform the PCM that the fans have been successfully powered up, and if that signal wasn't getting through then I reckon it would be giving you an error code, so you can pretty much forget about that particular fuse. I only mentioned it because if a spike is coming off of the fans at switch-off then it would travel to the PCM via that fuse, but aside from that it's of little significance.

As for looking for a spike with a multimeter, as I said, I doubt that you'd see much except maybe a momentary fluctuation in the meter reading, and that's because it's such a brief event - just a few milliseconds and then it's gone. If your meter has a peak-hold or max-hold feature then it would be worth switching that on in the hope that it might just record it. Also, I'd set the meter to its highest DC voltage range, which is probably 1,000V, because if a spike exists then it would exceed the limits of the lower voltage ranges.

Your battery voltages look ok. The voltage after sitting overnight is low, so the battery is obviously a little discharged but that's not a cause for concern, because it's to be expected if the vehicle isn't being driven daily. The voltage at idle and above idle are both within spec for your vehicle (14.1 to 14.7V) so that's fine too. It's a long way away from being a comprehensive test, but I just wanted to rule out the possibility that the electrical system was running way above or below its normal voltage range.

That's an interesting point about compatibility between the PCM and the engine, and it would be worth checking out, but I notice you said that the near-stalling issue already existed with the original engine so that might suggest that that particular problem is not a PCM compatibility issue.

Regarding the CCRM - if you're not accustomed to working at component level then it's safer to treat it as a sealed unit and confine any testing to the exterior connections. You could check for voltage drop across the various relays' switched contacts via the unit's exterior connections, but that still wouldn't necessarily be a conclusive indication that the unit is good.