Post#2 in this thread answers the "how to remove question": https://www.ford-trucks.com/forums/11...lp-needed.html

 

Yes , Electrolytic Capacitors do have a Life Span , it is greatly affected by many factors , depending on what they are used for , how often they are used in that circuit , and in my opinion temperature of operation is one of the biggest factors , like all things , some manufacturers design many things bare minimum , voltage rating is critical , if they are not installed with proper rating or have bare minimum voltage ratings then the life will be even shorter , you can also get capacitors that are made for high temp applications but they cost more and manufacturers rarely use them , you get what you pay for , all that said ........................ I have a feeling if I were to take it out I would find they are in need of replacement , and a leaking capacitor is a failing capacitor , and it can have many effects on the operation of any electronic or CPU based control not to mention that the oil that is leaking out of them can create capacitive effects on the PCB where it leaks causing even further problems or failure of other components .

Now I would like to report my findings on the self test that in my opinion could make sense but I will let those that are more knowledgeable comment .

This is what I got :

2 flashes somewhat consecutive then after a short pause 2 more , so I would interpret that as a 22 which low and behold is a map sensor failure .
Then I get 1 flash then after a short pause 2 more which I would interpret as a 12 which is a Idle control fault and I have no clue what that would mean unless it is referring to unstable idle which is what it has intermittently or maybe bad MAP is causing this ?

Then it gives me 2 flashes and then nothing following , so it is not even giving me the codes the scanner had on it , when the ECM did allow it to read them , I believe the idle fault is either the MAP ( if that is really bad ) or it was loaded because I disconnected IAC several times doing the other check and changing the throttle stop voltage a bit and rechecking .

So have no clue what the # 2 would be unless that is a "I'm Done" from the ECM , I am going to pull the computer tomorrow especially after seeing the pics of the one that was repaired , these capacitors are 23 years old and have gone through extreme heat and cold their whole life not to mention if they are leaking then it could cause even more issues and unreliable ECM function across the board .

Do I have to remove the Emergency Brake Assy to remove the ECM from the Drivers side Kick Panel ?

I will also summarize here , the only parts we have that are old are the MAP , Ign Module and ECM , ECM will work with scanner then will not work , will erase codes and then will not , will communicate and then will not , this to me is a Flag Big and Red , then we have the Ign Module , but I have yet to see a code for that if there is one , and then the MAP which I have not seen a code for but yet I feel may be bad as well and now the computer tells me it is bad , yet the scanner did not and after clearing and driving for hours it still did not , I was planning on getting a new MAP anyway , just like I was planning on getting the MSD Ign Module as soon as I find that many have not had issues with it .
Like most electronic items when you have intermittent issues it is a sign of soon coming death , and I have to count the issue with the scanner as well , this on and off reading and erasing is a problem , if it will read it and or erase it once then it should continue to do so , if it did not do it from the beginning then I would get it , but that is not the case.

Flashes were consecutive with Short Pause , then a longer pause , then a very long pause , so Flash..Flash.....Flash..Flash..............Flash.. ..Flash..Flash................Flash..Flash

 

Thankyou for that

Guy

 

While I didn't see it in action, the "timing" of those flashes I read this,

Flash..Flash.....Flash..Flash..............Flash.. ..Flash..Flash................Flash..Flash

as

Flash..Flash.....Flash..Flash..............Flash.. ..........Flash..Flash......Flash..Flash

22 and repeat for a KOEO test result, then single flash separator code, followed by 22 and repeat for CM trouble code. The flashes can be hard to follow/get 100% right first few times.

Edit:

No now I'm reading it wrong! scratch that,

That would be a "system pass" on both counts.

 

Run the KOER test see what you get back as a result.

Fuel Injection Technical Library » KOER Test

 

The Long ones are 4 secs , the shorter I would say one sec though the walk thru says 2 secs between .
2 flashes close together ( 2 seconds between maybe ) separated by at least 4 seconds then 2 more Flashes ( 2 Seconds between ) then a long pause , I would say at least 6 seconds , then 1 Flash ( 2 second pause ) then 2 Flashes ( 2 seconds between ) , ( at least 6 seconds again ) then 2 Flashes again separated by a 2 Second pause .

If I follow the walkthru right this would be a 22 and a 12 , but what is the lone 2 at the end , and it did not repeat them like it said it would in the walkthru , after this there was nothing for over 30 seconds , nothing .

 

If it is a system pass then the ECM is bad , because this motor has definite issues regarding a control and the only ones left are the ECM , MAP and Ign Module .
With the idle dropping randomly to 500 rpm ,random stumbling off idle and popping back , random weak acceleration , and it gives a pass , it is sick .

 

I will give this a go in the morning but not sure how I would know when the codes started , but i will try it once or twice , I did the other about 10 times before I got the pauses down pat , I need to go to a class for it LOL

 

There are aspects of the system the computer has no control of, system pass simply means that it. It tested the various sensors and they all respond within range.

I had similar issue with my 94 three four years back most of the time it ran fine but every now and then it'd fall on its face or rather have a flat spot in throttle response when attempting accelerate from a slow roll.

I tried everything attempting to find the cause and yes I got system pass for all three KOEO|CM|KOER.

Nothing I did helped clean this check this wiggle test you name it, nothing even so much as changed the timing of the event, always after a slow down or stop then taking off afterwords and from a slow roll.

I did get another computer, my local bone yard "loaned" me one for testing (I go there often as in "second home" dang near), naturally I'd keep it if corrected the problem but I had my doubts. So got em to agree to take it back if didn't correct the problem they agreed.

Different computer problem persisted so I stopped in the ford dealer and got with the old guy knows about these trucks. He hooked up a breakout box to it with a fuel meter on the dash (driving it around like that dang thing looked like it was on life support, hood open to secondary latch, cables run into window to box on seat and dash) and we took it for a ride, never fails he's in the truck he's driving it in fact won't do it.

He said just leave it on there and drive it day or two let me know what happens told me what to watch for on those boxes.
Finally it did it, the system would go full rich rolling to a stop then following that next take off would be the flat spot. Flat spot say 1/4 to 1/3rd of the pedal travel nothing there, push through that and hang on cus now its on. It would come out of it WOT or dang near it then be alright again run like nothing whatsoever was wrong with it.

Told him what happen he said "replace the O2 sensor", I said "I just did" he said only thing cause that would be the 02 sensor so I followed his many years of "wisdom" and experience over mine and replaced the sensor. We took the breakout box off, I left it there hoping that would fix it problem solved.

It did not, so some 70 bucks lighter yet in the back pocket for a sensor I had already replaced few days pryer didn't do anything for it and no no trouble codes system pass.

Well didn't know what to think or do so thought about it, he was dumbfounded the 02 sensor made no difference, got to looking it over only part I had never replaced, was still factory part was the ACT and ECT sensors.

I changed one at a time, changed the ECT sensor first drove it didn't make it more then a mile or so did it again nope no help. I return home put on the new ACT sensor, it has never done that again since then to this day in fact it still runs fine no more flat spot.

Should the ACT been flagged as out of range by the computer? yea maybe if it was in fact out of range to start with. Might have been the sole act of unplugging the old one plugging in the new correcting for an iffy connection all it took, I don't know I didn't put the old one back on to test the theory.

Yea it might be the computer, take it out and look it over if it has leaking caps replace them or it but don't replace it because it gives a system pass even though it doesn't run right. Many many things can cause issues the computer knows nothing about / has no direct control over.

 

I am most concerned with it being compatible with this scanner and then all of a sudden it can not communicate , it had only done this once before , I thought maybe it was a learning glitch for the 2 pieces , and now it cannot interface again but this time it is not able to at all , anymore , I also used to build computers , I used to service Communication Equipment , even some AM radio stations , all the computer control is great when they work right , but if there was not a issue with it in my opinion it would be reliably interfacing with the ECM , there is an issue because it has stopped is what I am saying , that is the issue on top of many others in my opinion lol , we will see , but I have to try , you had an ACT , but doesn't that measure air charge temp ? I only have the ECT in the coolant on this one and the MAP Sensor , you see if a control was bad then I should still be able to access computer with scanner , especially since I have done it more than a few times reliably , there may be another issue like the MAP or the Ign Module , but I still should be able to read and delete codes , I have done it quite a few times already
Processor driven things , you only need a small failure and everything goes to pot , you upset the balance of one circuit and it destroys the the rest , one little resistor , capacitor , cracked trace on PCB , Cold Solder Joint , it could even be a dry connection on the connecting plug for that matter , would and could cause this , some of these can even compensate for errors , but if they do it for extended periods of time , they have like little strokes , just like "I do not want to talk to your scanner anymore" , its not mechanical any more , at least that part
I really think there is a issue with the ECM , and the issue with it all of a sudden not wanting to communicate , in a Data Processing world , that is a serious problem .

 

Here's another of my takes and is not directed specifically at n4ynu1010's current problem.

There are three electrolitic capacitors on the circuit boards of "our era" EEC's.
The three elecrolitic capacitors will fail or already have failed due to age.

I'd be willing to bet that two of the three of the electrolitic capacitors are located in the following EEC circuits.

1. Fuel pump circuit or fuel pump timing "on start" circuit
2. EGR/EVR circuit

It would be very interesting to have the "correct and accurate" information about what circuits the three capacitors are located in and what symptoms would appear when they start to fail or have failed.

Bob

 

That's because Ford didn't add serial data stream until '91

I'd say it is quite rare. There are more EEC-IVs still working then not. The one from my old '87 still worked fine too. I've seen 50 year old electrolytic capacitors that are still fine. If the capacitors are of a quality brand (Rubycon, Panasonic, etc..), and of proper rating there is no reason they shouldn't last 20,30, or even 80,000 hours.

The capacitors have nothing to do with the fuel pump priming or EGR. The fuel pump prime duration is controlled entirely by the processor. The reason you often see the fuel pump constantly running on a failed EEC is because Ford designed the system to do that. It's built into the hardware to turn the fuel pump on as soon as the EEC gets power. Once the processor has read the ROM and initializes, it will turn the fuel pump off after ~1 second. If the processor never initializes (due to bad capacitor, bad ROM, etc..) the fuel pump will never turn off.

The caps generally are to filter noise and make things more stable. They seem to effect PIP decoding and O2 sensor readings as they start to fail, then gradually the ECU succumbs to excessive electrical noise and can't run stable anymore.

The way these computers work is that Ford programmed in acceptable ranges for each sensor. Sometimes when sensors go bad, they go outside those accepted ranges at which point the computer will promptly ignore the sensor and throw a code. Often though the sensors fail "a little bit" and send garbage - yet still technically valid information to the computer. The computer will then make its calculations based on incorrect data. That's why you can get a System Pass but still have bad sensors.

Modern EFI systems are programmed to recognize things like sensor patterns, and are much better about detecting and dealing with erratic/failing sensors.

What I would do is disconnect the battery, pull the computer, check it out, put it back in (assuming no obvious signs of failure) then try pulling the codes again.

 

That is what I am going to do , even though this is not as advance as the newer ones , still a failure could cause a intermittent problem , like I said in the post , my major concern is that it is intermittently deciding to not communicate when it was doing fine , to me this is a problem , I have dealt with so much electronic controlled mechanical equipment , I just know from many other applications this should not be happening , there is a problem , I may find it is just a dry plug connection , if I see that , I may just lube it up with some of my DeoxIT and plug it back in and try again , but just to be safe I do want to look it over , the engine compartment when I got it was full of mud and we all know what that means , lots of water everywhere , not to mention the hood was all messed up alignment wise , when it rained the water just ran down the firewall and that is where the harness plug is not to mention about 3/4-1" of the ECM Chassis , this truck had so many issues , I have been frt to back , shocks , drums , rotors , pads shoes , rebuilt motor , TPS was bad , EGR and Vacuum Switch , Wires ( still had stock original wires ) , Fuel Pump ( Frame Rail ) , Fuel Filter , Serpentine Belt , IAC , the seat mechanism for moving up and back was totally torn up , both door pin Sleeves and re-adj , new wiper blades , repaired glove box lock / dash support , condensate drain , cleaned evaporator coil ( full of mud ) , replaced Compressor for A/C , had to remove condensing coil and flush mud out of that , found out it was in there after A/C ran for 30 seconds and quit , put gauges on it , pulling vacuum on suction so I knew I had a blockage , removed refrigerant and it was full of mud , so had to slean and flush system , replace o-rings ( with the new type of course , Suction Hose w/ Accumulator , Dryer & Low Pressure Switch , had to replace exhaust pipe between muffler and Cat , and right before I got it they replaced both tank hangar assy's with pumps and the ign coil cap and rotor , when I say the only original parts left are the Ign Module , Dist. and ECM , I mean it LOL , unless you want to count the Ball Joints and U-joints hehehe .
Right at $4000 ( not counting the purchase price , it was a gift ) and still got a pain in the butt issue , when I get done , it should be still running when I am dead LOL , my son will have a antique F150
I really hope I find the Computer is trash or needs repair at this point because I want some closure , I did not randomly replace everything , everything was failing , I know if you get a 23 old P/U it will need work , but I was not planning for restoration LOL
I will keep you posted , gonna tear it out tomorrow

 

First of all Ian, DANG, you type fast.

Now:

There are more EEC-IVs still working then not.
True, but you'd also have to say there are more EEC-IVs failing now than there were 20+ years ago.

The capacitors have nothing to do with the fuel pump priming
Once the processor has read the ROM and initializes, it will turn the fuel pump off after ~1 second. If the processor never initializes (due to bad capacitor, bad ROM, etc..) the fuel pump will never turn off.
Ummmmm...... to me that's a contradiction that you've written here

The caps generally are to filter noise and make things more stable. They seem to effect PIP decoding and O2 sensor readings as they start to fail, then gradually the ECU succumbs to excessive electrical noise and can't run stable anymore.
Yes,true,I'll buy that, but, isn't the EGR/EVP circuit in fact controlled by the O2 sensor readings ?????

Maybe I should have stated in my earler post "I'd be willing to bet that two of the three of the electrolitic capacitors are closely associated with the following EEC circuits"

n4ynu1010 has a problem.
Lets see how it unfolds.

Bob

 

What I was saying is the capacitors are not directly part of the fuel pump circuit, and there is no fuel pump "timing" circuit. If a capacitor completely fails and the ECU never starts up, the fuel pump can't turn off. But even a completely failed capacitor doesn't necessarily mean the ECU won't start.

The only thing the O2 sensor does is trim the air/fuel ratio. The EGR is activated at cruise once the computer detects a part throttle load at speed.