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-   -   ecm questions. (http://www.specialservicemustang.net/forums/showthread.php?t=6759)

meders 05-04-2018 10:04 PM

ecm questions.
 
no one has any rebuilt ones for sale. was wondering if anyone can recommend a technician that does this. i had an old friend, that teaches electrical engineering at the local tech school, replace the (2) 47 microfarad capacitors that were seeping and had severely corroded legs. the other one was ok.

car fired up and ran, sorta rough then idle settled and was normal, then turned it off. now it starts but idles low(400rpm) then dies.

anyway, i was told by a fox gt owner that when the computer goes into closed loop is when it starts failing. i've owned the car 2 years and it came with CAI and no cats, other than that all stock.

any help or repair tech referral would be greatly appreciated.

JerryPHX 05-05-2018 10:47 AM

ecm questions.
 
Just checked online to see availability of a ECM. Rock Auto has none in stock but O'Reilly's (sp?) does. I used 1993 Mustang, 5.0 since I don't know the year or what car you are talking about.

Remember, after a ECM or battery is disconnected the ECM has to relearn everything. Years ago a dealer tech told me to start the car and hold the rpm's at 2500 rpm for two minutes then idle for one minute and then two minutes at 2500 rpm then let it idle before shut off (all this while parked).

Also, was the ECM "reflashed" after you had it open?

meders 05-05-2018 12:38 PM

it was not reflashed. what is that? i'll look t up. is it something i can do?

meders 05-05-2018 02:04 PM

sorry i forgot, i have a 91 schp w/ 5 speed.

chp1982 05-05-2018 08:30 PM

Finding one ended up being quite the task. No stores have the rebuilt ones.

If you're on Facebook, there's a guy named josh popper who sells rebuilt ecm's. He is also on eBay selling as Encore. Don't get thrown off by the prices. I paid 175 or so for one and sent him my old one for a core refund.

He even sends a video of it working.

JerryPHX 05-06-2018 02:41 PM

Reflashed?
 
I was told back in 1986 or 87, by a Factory Rep that once a ECU (his words) was opened up and worked (on the inside), it "loses it's Operating System and had to be Re-flashed".

Just think of it as buying a new PC at BestBuy without an Operating system installed (software). Once you install Windows or some other system it will work fine. A ECU can work but doesn't know if it's in a 5.0 Mustang or a 6cyl F150, without the proper programming (called "apps" today). So it doesn't know what parameters to work towards. During that period, your ECU in your 92 visually looks just like the ECU in my 94 F150. It's what's programmed inside that counts.

At the time (1986) that could only be done at Ford (computer controlled engines were NEW back then). So it had to be sent back, but now the Speed Shops advertise that they can re-flash a ECU. I think a lot of places now have the programming. That's why if you buy an engine at a recycle yard the ECU goes with it.
I'm not saying you need this but it's something to keep "in mind" while your checking for lose/damaged wires, weak TFI or vacuum (sp?) leaks.

Do you have an ECU from a friends similar car (doesn't need to be a SSP) that you could swap out and then see how the car reacts?

Let us know what you figure out,
Jerry

meders 05-06-2018 03:41 PM

i had someone lend me one they said was good but when the key is turned on the fuel pump will not shut off.

with mine the fuel pump primes for about 2-3 seconds. when the car died on my in august i started with a coil, there was no spark. then moved to tfi, then to the pip in the distributor. was told there was enough play in the gear that i should get a new one.

at that point was loaned a code reader and could only get KOEO codes. it was showing errors for O2's, BAP, ECT, ACT, MAF. then i found a code reader that displayed numbers instead of counting beeps. so this past tuesday the car ran and idled for more than 10 minutes then blah it dies. starts up and idles around 300 rpm till it dies. ran KOEO after that got 11 - 10 and 11 in continuous memory.

before i posted this the other day i read online about the ignition switch and a recall on them. went to ford dealership and it was changed in 1997. figured i'd give that a shot. $18.18 and no change. the old switch was loose between the metal and plastic. going to find a shop tomorrow and check into reflashing. then look into this encore recommendation from above.

i am no mechanic, i just want it running again or give up after 10 months of chasing gremlins.

JerryPHX 05-06-2018 07:29 PM

Don't give up!
 
I tried to look-up the 10-11 code but my old list only has two digit codes. Later years went to three so a found a digit list on-line but I don't know how to convert your numbers to three digits.

You do have a lot of codes showing which leads me to think about the ground or lack of it throwing everything wacky. Grounding is very important. I can not stress it enough. The sensors need a perfect ground. Did you check the cable from the battery to the body and then runs to the engine block. Please make sure all you grounds are not corroded/ rusted. They may look good visually but I would disconnect them, clean them and then re-install along with a spot of Dielectric grease.
Then check all the wiring under the hood.

I'm not a mechanic either (at least not since the late 60's) but simple stuff can be looked at and confirmed by an owner. You have to stop throwing money (parts) at this thing.
Can you get it to a Ford dealer (even tow it), pay the one hour rate for a Diagnostic fee and let them tell you what it needs? You don't have to have them fix it unless you want them to. I did this years ago and all it needed was two plug wires and something else I forgot. Before that I replaced a lot of parts (money) that weren't needed.

Oh, ECT= engine coolant temp,
ACT= aircharge temp sensor,
MAF= mass air flow sensor
BAP= (can't find)

What was this car doing or better yet what were you doing to the car just before this started?? You didn't Power Wash the engine did you?

Let us know,
Jerry

meders 05-06-2018 10:35 PM

i didn't type that right the 10 in between codes is a separator between the codes being read and the ones stored in continuous memory. 10 wasn't a code.

all i did before this started happening was lightly rinsed off the engine. it has the distributor cover and coil cover and i was gentle with it. nothing had been changed or modified from april 2016 to august 2017 when this started.

i looked up that encore mustang guy and they want 399 for a rebuilt unit.

is there something i should look into about the spraying off of the engine before i go further. all the grounds are clean and secure.

JerryPHX 05-07-2018 12:38 AM

Right off the top of my head....
 
Two things come to mind;

#1- I rinsed my engine bay (years ago) and the car immediately began running terrible. Long story short I took it to the dealer, they hooked it up to their machine and I wound up replacing two sensors. Can't remember which ones they were but it ran fine afterwords. I remember they were easy to get to.

#2- That rubber distributor cover- I wound up removing and throwing away after I found corroded contacts and rotor on one of my cars. IT holds in moisture! Removed them from every 5.0 I would ever own. So, look inside you dist cap.

Remember the wiring on your car is 27 years old. It's old and has cracks that can't be seen with the naked eye which will short out when wet. So are the sensors AND their connectors (whose gaskets have shrunk).
I'd find a way to dry everything out, like parking it in the sun with the hood up for a two or three days, while it's drying I'd unplug each sensor/ plug connection/ wire connection and even the coil wire at the coil (one at a time) to inspect the inside of the connection for moisture and dry it out. Then fasten the connector plug before moving on to the next.

Hope this helps,
Let us know how it turns out,
Jerry


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