Will do.

I am stoked now!

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Part of the initial process to any trouble shooting is to check grounds and un-plug and re-connect all the electrical connections, including the ECM. I don't know what you expect to see if you look inside the ECM, or if you even can or should open it up. Failure is rare on a Ford. I don't think I ever replaced one, other than early years when I was trying to use Mitchell's flow charts on diagnosis (replace ECM with known good unit and re-test). I have replaced a few on GMs when the injector driver failed.
My bet is on the EGR. Since you aren't afraid to throw parts at it, why not put on a new one. It sure could be carboned up and leaking, that isn't un common at all.

 

The three electrolytic capacitors have been removed. New caps have been soldered in. There was some circuit board damage that I attempted to repair. It is a multi-layer board.

Here's to hoping for a little luck.

It gets installed tonight after work.

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Got my fingers crossed for you !!!

Good job.

Bob

 

Life got in the way. I did not get to install the ECU this evening.

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And just an update from me.......

I did a little thinkin' about my truck, and the EGR restrictor plate fix that I had to do way back when.

I replaced the leaking capacitors in my "computer".
That cured a "random miss" and "popping idle" problem.

Installed (my version of) the "EGR restrictor plate" that's well known on this forum.
That "band aid" fixed the "bucking" while driving problem I was having.
I had replaced the coolant temperature sensor and the air temperature sensor amongst other various sensors to try and stop the "bucking".

I haven't, to date, read where ANYONE has had the definative answer as to why some of our trucks develop the infamous "EGR Stumble".

Now that I think back to the last time (recently) I was under the hood, I recall that my ERG valve WAS WORKING while the engine was still cold and not up to running temperature. Hummmm........
From what I have read and understand and verified by my Haynes manual, the EGR valve should NOT function untill the engine warms up to operating temperature. Hummmmmm........

Now that I re-read the link "ECM's (and same years ECM's) Failures Due to Age" I posted, It's possible that the leaking fluids from the bad capacitors I replaced could have damaged a circuit within the curcuit board that tells the CPU (within the ECM) when the truck has warmed up or what temperature it really is operating at OR a circuit that tells the EGR solenoid when and how to operate the EGR valve after the truck warms up.

And by the way: My computer has NO CODES in either KOER or KOEO.

This probably doesn't sound like much of a problem to most, but really think about it. The air fuel mixture would be wrong, injector pulsing would be wrong, timing would be wrong, and whatever else that is associated with the engine temperature would be wrong. Hummmmm..........

If I were a betting man, I'd bet that that leaking capacitors and the infamous "EGR stumble" are directly related.
Just my thoughts though.

Thanks for this mental trigger Suburban_B_Gone !!!
"There was some circuit board damage that I attempted to repair. It is a multi-layer board."

I'm gonna pull mine out again and look a little more closely !!!
It might be time for another "board level repair" or at worst a new ECM.

That's my story and I'm stickin' to it.

Bob

 

You know , that brings up an interesting point , I'm getting a lean code and a strange part throttle miss when I try to excellerate when the engine is hot . (cold no issues) . For grins I'm going to pull the ecu and inspect for damage . I have a snapon scanner and I'm able to run key on engine off and koer tests plus wiggle tests which show nothing out of the usual . I'll post results as I have time to dig in .

 

You get it !!!!!!!

As I had said before: "It cost nothing to visually check (other than time to remove and open up the box ) ,and, if you see that the capacitors are leaking it is a simple and inexpensive DIY repair, or, if you don't have any soldering skills find a buddy that'll do it for you for a six pack or whatever."

And: "check or even bother to check the most critical electronic component that controls how your engine operates"

Thats just great that you get the whole concept I was trying to convey.

PLEASE let us know what you found in your ECM and if or what you did to repair it. It's REALLY, REALLY important !!!!

Bob

 

Well the inside of mine looks like it got wet at some point , there is rust on most of the solder connections . Based on how it looks I'm surprised it starts and runs as well as it does . Guess I should look for a new one ...

 

And to take this one step further.........

My truck has an E4OD computer controlled transmission.
My tranny was rebuilt and it still has a problem with "slamming" into reverse.

Here's a quote from another person regarding their E4OD transmission and fix:"I think it is worth mentioning that my truck had shifted hard occasionally since I bought it at 123k miles, at 152k miles it had been doing it more frequently and I had began having some erratic fuel pump operation that I traced back to the engine computer. Upon replacement of the engine computer, I found my transmission shifted like a new unit.just a thought if any other issues start to pop up. My engine computer was rather affordable, under 100$ I believe, and this was a remanufactured unit from Oreillys."

Gee......might it be that a failing or failed ECU could cause all of these problems ??????

Think about it.

P.S. Good job Twistedwrench. Looks like you found the "culprit".

Bob

 

"these units don't fail"
But they do deteriorate over time , these trucks are over 20 years old ! I would say that obvously it shouldn't be the first place to start but, checking the ecu with a visual inspection ...

 

EXACTLY !!!!!!!

One of my first posts said: "Since you claimed the EGR is functioning mechanically, That's step 1

you've got to check it electronically. That's step 2

If it ( the EGR position sensor ) checks o.k. electronically, check the wiring harness and plugs. That's step 3

If the wiring and plugs check o.k., THE PROBLEM IS IN THE COMPUTER ie. the circuit board within the silver metal "computer" box. That's step 4

Then I added:"A simple "how to" check the ECU, Computer, PCM or what ever term you'd prefer to use, is to click on the link and look for an obvious visual problem on the circuit board."

Twistedwrench, you said, "Guess I should look for a new one ..."
Let us know if you get another ECU and what the end result (how your truck runs) was.

Good on you for paying attention !!!!

Bob

 

I installed the repaired ECU in the truck this evening. One of the two problems I was experiencing has been eliminated. I still have the non-stop fuel pump prime at start up issue.

I am going to take the unit back to work tomorrow, and examine it again under the magnifier. It has a multi-layer board with damage to multiple traces. It is time to decide whether I can repair the 23 year old unit, or look for a rebuilt unit.

I still believe that I am on the right track. However, my skills may not be sufficient for the damage on my unit. So far, I have less than $5 invested in this repair. It is worth another shot before I go shopping for an ECU.

Thank you for the opportunity to update my progress, and thank you for the support, FTE community.

.

 

Yep, right there with you.

I did the capacitor repair (yes, about $5 for me too) and my EGR valve operates when the engine hasn't come up to operating temprature, in other words my first repair attempt was unsuccessful too.

Bottom line here is: Even though we've done the obvious visual capacitor repair(s), the ECU STILL may not be, in reailty, repaired or even be repairable.
This realization is VERY, VERY important.

"It is worth another shot before I go shopping for an ECU."
I agree totally and when I get a bit of spare time, I'm going to do the same thing.

Thank you for keeping us up to date on your findings.....it's important.

Bob

 

i really appreciate all teh help guys, ive been very busy as of lately, and finally got into teh truck engine saturday, though i didnt crack open the computer and the auto parts store tested my ECM and said it was good., i went after the other part that came up on the computer scan, the MAP , it got replaced ,as well as teh coolant sensor, the mass air sensor, and new plugs and thermostat. oh yeah, a few weeks ago teh TPS got replaced too. now heres a kicker. ok, the mystery continues, the truck is running worse.... well was runnign worse. i cant get it to idle at all now. and if you barely touch the pedal itll kill it.. when it was idling saturday night, i found that if I remove the brake booster vacuum line, and cover most of the hole, it idles like nothing is wrong.... so my new question is, "what type of problem is the result of a vacuum leak making an engine run smoother?" could this be the idle air control module??? is there a stupid reason why my engine would needs massive amounts of vacum??? there was ALOT of air sucking from that vacuum, is that normal???? *sigh* this is neverending, im ready to give up... as for me checking hte EGR, i cleaned it, checked teh plunger for wear crakcs, bad rubber, no carbon, put a multimeter on teh sensor and it had no skips or misses on it while pushing and pulling hte needle. so in m yeyes, its not he EGR, especially since the EGR only operates while at running temp, this wont efect a cold enging not starting at all... im not being stubborn about hte computer, i cant imagine finding a new one is even possible.. and my stress levels on this truck is going to kill me. i think everything under the hood should be considered long before the computer comes into question, so ive double checked to pdead center and im positive im in time. had another question? when your at top dead center.... shouldnt the timing mark on the harmonic balancer be at 10 degrees btdc? ive manually rotated teh crack many times and not once did it align at TDC... this sems odd to me, am i crazy??