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1991 Ford Aerostar Van forum. Pages: 12Last

FrankD. on Mon July 03, 2006 3:35 PM User is offline

Year: 1991
Make: Ford
Model: Aerostar
Engine Size: 3.0
Country of Origin: United States

Ford Aerostar Van forum.


I am trying to help a friend with a 91 Aerostar Van with a 3.0 that has lost spark to the plugs.
What a joke the blind leading the blind.
Seams like there should be a Ford forum that would know all about 91 Aerostar ignition systems.

Thanks for any help.
Frank

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FrankD.

Edited: Mon July 03, 2006 at 3:37 PM by FrankD.

NickD on Mon July 03, 2006 7:36 PM User is offline

Trying to forget Fords, and it's working, believe your friend has something called a SPOUT connector that you have to either plug or unplug to set the initial timing and also has constant problems with the ignition module burning out, think they called that the TFI, but can't remember for sure.

Yeah, that's right, what a name for thick film ignition module. If you have an old fashion dwell meter, have to find the low side of the coil and hook it there for around 30* of dwell when cranking or hang in a volt meter and watch for pulsations while cranking that means the TFI ain't switching, but can also be a Hall Effect bad or even lack of 12 Volts to the high side of the coil. The latter is also a problem as Ford is using bare copper in the ignition switch to save on plating costs and the copper turns green. Did you know that copper oxide is an excellent insulator?

Very basic system Hall Effect triggers TFI, TFI triggers the coil, initial timing is manually set, PCM takes charge of the advance via the SPOUT connector.

I think....

FrankD. on Mon July 03, 2006 10:47 PM User is offline

Thanks Nick

“I think”

I think you have a Ford service manual stuck in your memory. LOL

This is over my head let me see if I can get Schroder over here to read this.




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FrankD.

NickD on Tue July 04, 2006 7:28 AM User is offline

Doesn't this van use a coil that looks more like a transformer with a connector on it? Recall cleaning the terminals on those as they get very corroded, has to have a mirror finish on it so you can see your smile. Believe the Hall Effect outputted 5 volt pulses to the TIF that also has a connector on it, don't quite recall the ground circuit on the distributor but also a problem. Most of the time, just corroded connectors and one advantage of buying all new parts is that at least half the connectors are clean, but the mating connectors are still corroded so this is only like a 2-3 month fix. Dielectric grease helps to retard the corrosion.

Most of Ford friends that take their vehicle to the dealer or a repair shop with ignition switch problems also pay to have a perfectly good ignition lock changed when the damned switch is the problem so they have to put up with two look-a-like keys. More of a pain in the butt to remove these switches than to take them apart, I use a buffing wheel to put a mirror finish on those three dimpled spring loaded plates and also the bare copper embedded PC like runs, need an tamper proof torx bit to get them out, then coat them with Lubriplate. And sit and wonder how a switch like this with a tiny point contact dimple can handle as much as 75 amperes under worse case load. Removing the lock is more of a pain, as that blocks the gear shift lever and locks the steering wheel, so when that is removed a whole bunch of stuff drop unto the floor. So best to leave it alone, but maybe spray some WD-40 into it.

Ha, if you buy new parts that have been sitting on the shelve for 15 years, they are also pretty well corroded by now.

dick2256 on Tue July 04, 2006 9:35 AM User is offline

Nick
On this 91 ford areostar I am trying to bypass the computor box and get fire without it,is this possible?
That SPOUT plug is a plug that lets you set timming without the computor trying to control it.
The only other thing from the ignition to that computor is a PIP (Profile Ignition Pickup and I am wondering what the voltage on that would be?
I have electronics background for over fifty years and opened the computor lid and found two electrolytic caps that had the one leg eaten off from what appeared to be acid and I replaced them. I am suspecting my problem is that box but would like to bipass it and get it to fiore before buying a new box @ around $180.00.
Dick

Chick on Tue July 04, 2006 9:52 AM User is offlineView users profile

Try a used one from a junk yard. Obviosly the "box" had a problem, and you will need very sophisticated tools to check it. A used computer is not that expensive. Hope this helps.

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

FrankD. on Tue July 04, 2006 2:51 PM User is offline

Hi Schroder (Dick2256) glad to see the link to AMA forum worked.




-------------------------
FrankD.

dick2256 on Tue July 04, 2006 3:21 PM User is offline

Thanks Frank D.
I polished all of the connections and retried with no results so now am looking for a used computor for this thing as that is all there is left to try.
A very good forum I might add.
schroder

NickD on Tue July 04, 2006 8:25 PM User is offline

The TFI is most likely and very problem phone, can look new and shiny, but not work. Coil only has a couple of wires on it, 12V for the primary with the other end going to the TFI for the pulsations. Would test the coil by simply hooking up a spark gap to the HV cable and hitting the primary with a clip lead hooked to 12 V with a 0.1ufd capacitor across it, should see a spark, more sophisticated was to do a Q test and also have a shorted coil tester. Can also test the coil for complete opens with an ohmmeter, but doesn't really tell that much.

Recall something about a limp mode where if pulsations didn't come from the computer, the TFI would switch over to direct, but if your EEC is shot, won't be getting any injector pulses either.

Can't quite recall on the Fords, think switching on the ignition would turn on the check engine lamp and the engine had to be started before it would go out unlike other cars where the lamp would come on for a couple of seconds, then go out. This is the self diagnostic mode, least tells if the microcontroller is working. Didn't really need a scanner, and LED in series with a 1K ohm resistor and a jumper connected to the diagnostic plug would show all the error codes with a code telling if the diagnostics was working. With that bit of knowledge, most the other stuff like the ignition and injectors were with transistors and could find one cooked out to save buying a new computer.

An alldata.com subscription would sure help with the code data and wiring, may want to think about that, link some where on this board.

NickD on Tue July 04, 2006 9:26 PM User is offline

Forgot about this get a piece of heater hose used as a stethoscope next to your ear and an injector to learn if it clicks, that will tell you something about your computer whether it's working or not while cranking the engine.

dick2256 on Wed July 05, 2006 7:50 AM User is offline

A TFI was the first thing I bought when this thing died on me and tried it but no fire so I put it back in the box also bought a pickup that goes in the distributor and have tried a working coil from another van.
Dick

NickD on Wed July 05, 2006 8:29 AM User is offline

Run any voltage checks? Have access to an oscilloscope? Are your injectors clicking when cranking? I bench test any module before replacing it, very expensive way of troubleshooting.

And yes, the parts dealers around here all have huge billboard signs, "no refunds on electronic parts", but that never stopped me when I buy something new in a box and it doesn't pass a bench test, I get refunds! You don't know if that new TFI module is good or bad.

One problem with Ford modules is that the interconnect between the connector block and the thick film module is they use a slide on connector at the thick film side that takes about a gram of force to slide it on or off, found several where this weak terminal slid off. Should have been soldered on in the first place.

I don't pay attention to "don't remove the cover, no user replaceable parts inside", the reason they don't want you to remove the cover is so you won't see the garbage on the inside.

The Ford IAR regulator is a real jewel of a design based on a Motorola patent, millions of the first ones produced would put the field drive transistor in the linear mode if you happened to turn the ignition switch off with the engine running above 1,200 RPM that would instantly cook it, a bad design fault. This can also happen if you run out of gas or have some other electric problem while cruising down the freeway. Ha, it just old and has to be replaced, BS, this voltage regulator is garbage as are most of the TFI modules with the same interconnect problem.

Can't spend a fraction of a cent to make the I/O circuits short circuit protection proof, one microsecond touch to Vss or Vdd, and a transistor pops rendering that module useless and these are very subject to a chain reaction where one module pops another, than another, damned poor design.

Don't even ask me about the PFE module and especially the electrically heated windshield circuit or the AXOD-E, or the electronic suspension control, or the......

dick2256 on Wed July 05, 2006 2:06 PM User is offline

I am fortunate enough to have a steth opscope that they gave my wife while she was in the hospital.
I hear no clicking of the injectors
On the voltage checks all checks close to what my book says they should be.
Dick

NickD on Wed July 05, 2006 2:48 PM User is offline

Can't read any codes if the computer is shot, suggested Dick try to hear the injectors just as verification if they were working, apparently they are not. Dick said he found two eaten away electrolytics on the computer board, these are normally power supply filters, but never asked him if he was getting the 5 volts on the board. These multilayer boards are not easy to work on, should follow Chick's suggestion and find a used one, but not in WI, wrecking yard liability laws permit these guys to charge more than what a dealer sells a new one for.

Agree that Dick should try to read the codes, those 30 buck code readers are nothing more than an LED in series with a 1Kohm resistor and a shorting switch and this information is on the web someplace. Like right hereOur friends at Bat Auto.

dick2256 on Wed July 05, 2006 3:35 PM User is offline

From what I have read the error codes are lost if you unhook the battery and I decided to put in a better battery and it set a couple days without a battery so I think I have lost the errors anyway untill I get it running and then it would store more code errors in the memory,if I am wrong on this let me know.
Dick

bohica2xo on Thu July 06, 2006 3:43 AM User is offline

Yes, disconnecting the battery will clear the codes. Sorry, I missed the part where you opened the PCM. Have fun.

.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

NickD on Thu July 06, 2006 7:09 AM User is offline

It's just that Ford or nobody for that matter will sell you a ROM chip or the microcontroller for less than a buck a piece or even with a fat markup, both for under ten bucks. Once these components are bad, you are dead and have to replace the entire computer, surprised it's only 180 bucks, some cars are over 1200 bucks.

Doesn't take much to fry these, if Vdd exceeds 7 volts, it's cooked forever, just probing the unidentified pins will show a flat line on a scope, every pin, even with a good 5 volts on the processor. A poor ground or bad battery connection is all that it takes. The Ford alternators can output a 150 volt spike that will fry a lot of stuff with just a poor battery connection, but that alternator output lead goes directly to the electronics, Plus you also have the infamous BSS spade output terminals on the alternator that corrode like crazy, when I was trying to drive Fords, would solder them directly and replace the battery every three years and check the battery connections three times per year. Plus you may also have that IAR regulator where the field transistor shorts off if the engine is killed for some reason running the alternator at over 3,000 RPM. With a shorted field transistor, alternator outputs full current and if the battery can't sink it, voltage will skyrocket to over 100 volts. Least GM puts in avalanche rectifier diodes that sinks the output voltage to under 23 volts if the field transistor shorts.

If you have this problem, more than the EEC will be fried and Fords have had their share of pending lawsuits with underhood fires due to the BBS connector, but no one has won yet in a court of law, believe me, many have tried.

Ha, Ford buys a standard 2N3055 transistor, but has the vendor put two chips in the case thinking they can get 30 amps out of it to drive the blower motor, doesn't work that way.

My own opinion with the very poor electronics, total lack of protection, problems with HG's, AXOD's, climate control, back death, springlocks, front struts breaking off, better off walking than having a Ford, but also have to say the Chrysler mini's are not much better, strictly a maximum 100K vehicle with the same HG and transmission problems. We had good success with the T-Bird if you stayed on top of the electrical and didn't mind driving with open door windows, that four foot long door window was only supported by two tiny plastic tabs that constantly broke off, Ford wouldn't sell you those, but only the window for 150 bucks that would break shortly after. And the Escort was pretty reliable, rest was junk. And they wonder why they are having financial problems.

dick2256 on Thu July 06, 2006 9:06 AM User is offline

This computor I have is a remanufactured one and has a number 8-5140 does anyone know the ford part number for it? Would it be? #F29f-ca.cb
can buy remanufactured for $158.88 plus $70.00 core charge.(partsamerica.com)
Also mine has a code # 1101MG would I need to tell them that? That is a calibration number.
Dick

NickD on Thu July 06, 2006 9:36 AM User is offline

Ford typically has over 120 different computers per model year depending on model, engine, accessories, wasn't aware that there was remanufactured units, know many have tried, just was impossible to come up with the proper test procedures as just too many different types are out there.

Would contact your vendor and ask them exactly what information they require for the specific EEC for your vehicle, VIN should be one of the numbers they need and maybe some information off your emissions label. Hope this helps.

NickD on Thu July 06, 2006 10:41 AM User is offline

Did have an extensive but interesting talk with a guy that is on the web that rebuilds electronic instrument panels with key questions on where he was getting all those ASIC's on the PCB. He really hedged around this question leaving me with the opinion that if the ASIC's are shot, the core is dumped. Typically I have found hundreds of flux solder joints on these things due to improper wave soldering or even hand soldering that doesn't burn off the flux. That left acid corrodes the joint between the lead and PCB and you can measure a dead open circuit across the two. Some are even extremely difficult to spot under a high power magnifying glass, but a touch of a hot soldering iron releases that tell-tale sign of a puff of flux smoke. Been lucky so far as this was the major problem, did have a problem with an inverter on one and quickly learned the driver transistors were operated at twice their rated power.

With experiences like this, if I see a vehicle with an electronic dash, just keep on walking, pain anyway, can't see the darn thing when the sun sets at your rear.

Both my Ford and GM dealers don't even sell over five year old dashes, but want 300 bucks extra to send it in for me to some repair shop, just feel these guys are finding working cores if they even have one like yours laying around or just wait a couple of months. These ASIC's for the most part are common CMOS circuits jammed in one DIP to save on PCB space, but one of a kind and the OE's only buy a given quantity of them and that's it when the last one is gone. Feel the same is true on EEC's or PMC's whatever they want to call those things.

dick2256 on Fri July 07, 2006 12:04 PM User is offline

going to do some searching for a computor for the van so will quit bugging you guys about it but will keep you informed on my progress or lack of it with this one.
Thanks for all of the help.
Also have a buick park avenue v6 1992 that has been to various shops for an ignition problem .
as it approaches a hill and is needing to kickdown to a lower gear it does a lot of back firing
Just something for you guys to think about I think it is like the spark advance isn't working but that is all done with the computor,one garage did put in a new set of spark plug wires but no difference in performance,also was taken to a transmission shop thinking it may have been a tranny problem but it tested ok.
Dick

bohica2xo on Fri July 07, 2006 2:10 PM User is offline

Ok, I will say it one more time. BUY A CODE READER.

That "backfire" could be any of the following:

13, 14 EGO problems

16 This fault causes erratic shifting, forces trans to 3rd gear when set.

44, 45 - with or without code 48 Code 48 addresses missfires like you describe.

39 TCC lock / unlock issues A locked TCC will make kickdowns a mess

54, 55 EGR issues, another source of "backfires"


People will spend 30 bucks on a wrench to reach a distributor bolt, but step over a diagnostic tool. The book that comes with an inexpensive scanner is worth the cost of the tool. The price paid to the transmission shop would pay for the tool, which reads the trans codes too.

For the naysayers that claim it is only a lamp & resistor, here is a pic of the ford unit:




Owning a computer controlled car without the tools to communicate with it, is like owning a computer without a monitor.


.

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

NickD on Fri July 07, 2006 2:54 PM User is offline

LOL, that code reader is strictly for a Ford and Dick's backfire problems are with a 92 Buick, more than likely, the problem with the Buick is the direct ignition system module that can be removed and checked for high voltage flashing. Timing is fixed with sensors both under the damper pulley and camshaft. Our manufacturing cost on a replacement module was under 14 bucks as a guide for the price for a new one. System has three separate coils and sounds like the right coil is being fired at the wrong time. The module also has a limp mode feature.

Don't want to disagree with these low cost scanners, but still a switch and a LED, and gets tricky at times to count the pulses, actually with both the Ford and the Buick, the check engine lamp will also flash out the codes, so just need the jumper. Buick is nicer as the diagnostic plug is under the dash so don't need long wires. Use to be for around 50 bucks, could buy an LCD scanner that showed the numbers.

I found lots of code errors in the booklets that come with these low cost scanners and they also cover too many different vehicles that adds to the confusion, better off with a shop manual. Most dealers I know of will let you make a copy of that one page in the manual, but may need more to learn what to do about a specific error code.

Just happen to have a 92 Buick shop manual along with the huge 450 some page electrical manual, the Buick electronic system is somewhat of a nightmare and much more complex than the DeVille. That's why I got a DeVille instead.

bohica2xo on Fri July 07, 2006 3:20 PM User is offline

Like talking to a brick wall. I said it was the FORD tool. The tools says FORD on it.


Nick I have yet to find a code error in Actron's book. Better to have the book, than nothing at all. The last factory manual set I purchased from the dealer was over 450 bucks.



A circuit board with at least one IC on it, in a plastic case is still "just a light". OK. Yes, you can use the check engine light on Genital Motors cars. Personally I think having things like the audio circuit for the "wiggle test" and the mating connector for the vehicle to be worth the cost. If you would rather read the codes through the MIL - fine.

But READ THE CODES. Guessing, replacing parts, etc. is a waste of effort. So far this buick still has problems, after multiple tries. Drive it, duplicate the failure, and read the codes. Simple.


.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

CorvairGeek on Fri July 07, 2006 8:06 PM User is offline

Drivability and transmission concerns can be the timing chain on the Buick V6s. It is a 90 degree V6 so there are comprises in how it was balanced (even though it is an even fire after appx 1979?) How many miles are on it? It will have a steel cam gear, but I would have great concern about the chain after about 150K, even with good care.

Jerry

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Jerry

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