It's rare to find a mechanic that can do that kind of proper diagnosis of an eledctical component these days. Many of them are really good parts swappers. Good work!

I noticed the temperature gauge was close to the "C" mark. This era of Ford computer generally won't enable adaptives (learning mode) until the engine has hit 160°F. Closed loop will work prior to that, but no long-term corrections will be committed to memory. Additionally, the "test" ECU you used was labeled 5.8. The 5.8/351W of that era had 19 lb/hr injectors. The 460/7.5 had 24 lb/hr injectors. So any given pulsewidth to injectors would be injecting much more fuel than anticipated. It would inherently run very rich with that computer, and even in closed loop it might not be able to fully compensate.

I've been watching you for a while and I didn't think anyone else did board level repair AND automotive repair(I've repaired a few ecu's as well)....Great work and Thank you

23:00 most of these old OBD1 systems required a minimum of a 30 minute drive cycle before it would store parameters and go into normal operation.

The oxygen sensor needs heat (400C/750F) to produce energy (voltage ). So, if the sensor doesn't have a heating element, it may take several minutes before it becomes fully operative. It's up to the ECU software to figure out when the oxygen sensor is hot (temp sensors, fixed delay, etc ) so it can start reading the sensor and bring the ECU into a closed loop. Anyway... Thanks for yet another interesting video.

Only in the southwest can you find such an old vehicle that hasn't rotted away, much less runs.

Thermostat could keep it from closed looping too because it's not up to operating temperature.

Really nice job! I'm not sure which is more fun to watch, you diagnosing cars or diagnosing pure electronics. Either way, you have a huge amount of knowledge! Thanks for taking us along. Now i need to recap my 94 Ranger.

Sometimes, to "reset" an old ECU, you need to not only depower it, but also short the power leads to it as well. This also applies to OBD II's now and then, as I had a Jeep Grand Cherokee ( 2000) where my battery was going weak and although the engine ran, it threw a low voltage code. I disconnected the ECU / PCM fuse, shorted the input power lead to it, towards the PCM, and when I reconnected and restarted it, it saw the low voltage as its new baseline and was happy until I got it home from PA to Chicago, where a new replacement battery fixed all of the associated ills

That van is CLEAN! I wish we had rust free old vehicles in the Midwest.

40 years ago I had a 1981 Chevrolet Citation that ran like a top. One day I go outside to start it and it cranked and cranked and would not fire. I did all the obligatory inspection for a failure point to no avail. Then I thought about how cars were having computers in them around that time and I suspected the ECU in that model was at fault. I didn't even know where it was. After rummaging around under the hood and dash, I found it tucked away behind the glove compartment. I popped it out and brought it to my ham radio service bench and opened it up, not knowing what to expect. There, staring me in the face was a thick board trace that had popped. I checked north and south of it for any component failure, finding none. I scraped and bridged the trace, soldering a bare copper wire across the gap. Put the unit back in the car and it fired up immediately. I had ducked a bullet. My guess is if I had to take it to a dealer, it would had been an excruciatingly big ticket item to fix. A few hours on a Sunday afternoon, a piece of wire and some solder did the trick. I kept the car for another several more years of great service and gave it away to a friend who needed a ride. If I wasn't a ham, I would have gone to the cleaners. Thank you Shango for showing the potential of repairing old tech. In your case you know what you are doing. I only got lucky in my case.

Didn't know you also did cars, that's cool. Guess it's much similar as radios. I do random electronic repair too, DVD players, washing machines, PC's, and vehicles. Don't have your skills though, but most often manage to resolve things. Of course, Rebelsus have helped alot.

It must be the tire tread pattern, but at about 30 mph, the audio sure sounds like an EMD v16 or v20 when they are just coming off idle.. Love that sound.

I replaced the ECM in my 93 Dodge last year. That thing had a gel I could not get off without tearing it up. A $300 unit on my truck. Cheers! 🍻 Al

Wonderful video on the Ford OBD1.

Nice fix . I do board repairs too. Clusters,DVD players,bcm ,ecm etc I like the depth you go into with it.

I am working on my 94 E350 RV with the 460...My ecm is the RUB0 code number..But it looks exactly the same as yours with that cap bleeding al over the board.. At 4:25 you were showing the traces with the vertical trace being open. Mine has the horizontal trace from the cap to that 4 color resistor that is open.. I actually took a screen shot of this at 4:25 and with your explanation of the traces I found that open on mine. THANK YOU!!!

I didn't know you worked on automotive electronics. I thought you did mostly radios. Anyway, very educational. Maybe you could do more automotive diagnosis and explain how it all works. Thanks!

I fixed a few ecm on gen sets industrial equipment. Replace trace with thin copper wire solder to board. CAT ecm I just bought rebuilt $2500 and $700 for dealer to flash it.. Insane. New age stuff insane expensive. You may wanna look into mid 90s CAT Cummins ECM repair. Ford and most ecm control cars trucks need to be above 160-190° f to go into closed loop.

What a blast from the past! These OBD1 vehicles were tougher to diag. I don't remember Ford having data stream at this point.

EEC-VI closed loop story: I found my 88' Ranger went into closed loop almost shockingly fast with a cold engine (60 - 70 sec at 40 - 45 F), with a new O2. Then closed loop would randomly start taking forever. The heater in my replacement Bosch O2 sensors was burning out really fast because EEC-IV have the heater wired directly into key on power, not through a relay to switch off after a certain temp. I don't think the replacement elements are up to the oddly high duty cycle. The sensor works without the heater, but is difficult to bring online, & quite lazy when cold. I found unhooking the O2 heater after reaching operating temp didn't effect the sensor reading and am planning to film making a modification to add a temp dependent relay to my EEC-IV to stop the consumption of these 02 heaters. (I rarely reach operating temp) Fun Fact: When changing altitude significantly after startup on EEC-IV management, always cycle the ignition to update the computers altitude/barometric reading. (as you stated this happens during after KOEO before KOER) I have also installed a O2 gauge in the dash in the quest to learn the throttle magic required to activate the Ultra Lean Burn feature of EEC-IV, where under the right conditions the EGR commands are be perverted to cool the otherwise disastrously lean condition the EEC can apparently adopt when the planets are in the right retrograde and the Schumann is 7.3Hz. (apparently different than a regular NOx quash dousing, and seemingly would undo all the NOx saving done in the other regular EGR mode)

I see the ‘Rear Abs’ light is on. It was very familiar ‘cause my ABS is out in my ‘97 Explorer. Gotta say it seems to brake better without it (except probably on water, of course).

The delay going into closed loop may be indicative of a stuck open thermostat.

Shango,Interesting video.I’ve seen a couple of your others on car ecu’s where the traces were really badly damaged by capacitors and you got them working. I bet you’d have a full time job if you decided to take on repairs for other people doing just these car ecu’s. I’m so glad that I’ll never have to deal with issues like these since I drive 50’s and 60’s cars. Just rebuilt the Carter carb on my 1958 Plymouth the other day after over a decade of service. Kit cost me all of $15.00 and I did the work myself. Cars have just become so needlessly overcomplicated these days. Computer controlled transmissions,computer controlled everything. Transponder keys. Computer controlled ignitions. Even though this is an older car (I think you said it’s a 92) it’s still new enough to have these kind of computer problems,although the ecu did last 32 years. It’s just a shame that even though the car is (presumably) mechanically sound that something like this took it out. I realize the manufacturers don’t plan on people keeping cars 32 years,but A repair like this would be beyond most owners ability or knowledge. They would either junk the car and go into debt buying a new one or have to take it to mechanic and bend over and grab their wallets. I’m sure they would charge at least $1,000 to replace it the ecu, Likely more. The late 80’s and 90’s cars seem to be much more mechanically reliable than the newer cars. More and more these days it seems people just stay in continuous debt leasing new cars and then dumping them every couple of years before the onset of expensive problems.

Great video! Looks to me as if it's a little too cold. All the fords I had ran on the "O" on normal. Also when it starts it sounds like it's trying hard to turn the starter motor. Weak battery? Bad connection? I had one do this and the voltage dropped low enough it would reset the ECM when it cranked. Also some of the heavy duty emission vehicles we had here in Alabama and Tennessee would run in open loop at idle. I'm sure that's not the case in California but I remember chasing an open/closed loop problem 30 years ago on one and finally got on the tech line to Ford and they said it was normal to fall back into open loop at idle. Go figure. Great looking van. I'd love to have it. Sounds great! Thanks!

Do I see tantalum’s ? Those are a magic smoke moment waiting to happen. Conformal coatings can be both a blessing and a curse. Old MOTORONI Moxy mobiles were open back radios, when you have a fleet of fertilizer trucks out there you wind up with corroded traces in the back of these radios. Then conformal coatings are a blessing.

An honest and true service tech to component level with verification! I'm surprised the DVM clock is fast enough to catch the sawtooth pattern of the O2 sensor. Kill it George!

Nice job man, those old EFI vehicles will start to need some love with all this caps pucking. I would add a drop of silastic on the caps. Two leg components like caps can break free (long term) because of vibrations. Well, it didnt happen here clearly LOL, but it is a common practice that does not hurt.

My experience with older ECUs is they always run kind of funny after power has been disconnected for a bit. They seem to kind of reset themselves, then smooth out over time.

Finally, Shango posts something other a tv or record player video!

I ♥️ big block carbon pumps.

The ECU will probably have forgotten all of the learned values for the fuel trim, injection/ignition timing, manifold pressure etc when it was disconnected from power, probably took a while to relearn the parameters. Also the temperature of the engine will fluctuate when idling/driving so that can cause it to flip in and out of closed loop.

Nice van and diagnostics/repair. Great video Shango066 👍

I like when you repair cars, i kinda like when you repair everything.

Nice work Shango, It's great seeing ECU's getting sorted out because as you say the people selling referbs are charging ridiculous prices on eBay that's if they are referbs at all. I guess ECU's suffer the same leaking cap issues everything else does.

When you disconnect the ECU from power it forgets learned fuel trims. It took while to relearn new fuel trims.

I have a 1992 Taurus and the radio just failed due to capacitors. The engine and ECM is a 1995 though - I should probably recap it soon.

Great video, I'll have to like this video. My ranger is going on 30 years old, so far no issues other than a very random start/stall. Random like twice a year.

Great job as always Shango. I fear that PCM and other electrical problems like this will eventually sideline many older vehicles (roughly 1980 up) that are otherwise perfectly usable. Once the critical electrical parts and sensors become unobtainable it will be game over.

Nice fix Shango, I enjoy all your videos. Ive seen your other automotive related videos as well they are always interesting, you mention you work on a lot of those, can we see more videos of you work on cars please

Been decades since I used a gas analyzer, but I do remember the older vehicles would fall out of closed loop at idle and was normal. Some of the Canadian versions of fuel injection on GM stuff was non-feedback as well (mid 1980's).

I had a break like this that would only go open when the weather dropped below freezing. It was an E38 740 BMW and I nearly scrapped that damn thing for not starting on cold mornings.......in the end I pulled the ECU and checked various voltages and noticed the power would drop every time I pressed the meter probe on a certain area on the PCB.

These are interesting, Shango. Thanks.

Dude just subbed bc you’re the man and thorough. Much appreciated. What would these numbers look like if someone were to delete the egr and air pump?

So Shango is an auto technician by day, and does electronics in his spare time? How did I not know this? I’ve watched all his videos and have seen his other vehicle and small engine repairs and such, but didn’t make the connection that this was his day job. MMMAN, I wish I had 1/100th of these skill sets!

This is a very interesting video, Shango. I worked on cars in the 70's that had no computers, or O2 sensors. Lol

Awesome work and video. I also have an old 1989 Chevy S10 4 banger (Iron Duke Tech4), and I think it's about time to check and recap the ECU, after more than 30 years I bet the electronics in the ECU is quite worn out.

A lazy o2 sensor can be marginal or stuck, and work ok when heated fully and driving. The closed loop versus default strategy of the ECU should not affect the 02 sensor voltage. They only control the ECU has over an 02 sensor is supplying heater circuit voltage and VREF. The sensor oscillates all by itself when powered and in the presence of heated combustion gasses.

Did I read that odometer right? 315,000 miles? Great video. I'll work on tube radios but this is at another level.

With those old cars with big engines you need an engine oil temp of at least 60 degrees celsius and a white hot O2 sensor and cat to get a realistic result on the analyzer. After I fix an injection or ignition problem on one of those cars, I drive them hard for a few miles before connecting the gas analyzer. Or I disconnect the brake booster to get an intentional massive air leak and then I rev the snot out of it at 4.000 RPM for three to five minutes until the exhaust smells like hot converter.

Coolant temp sensor has to be warm before it will enable closed loop, that might’ve been holding it out. If it needs a new thermostat you may be getting a check engine light soon.

I like how you've got a dyno and exhaust gas analyzer, but no scanner - the most basic tool for doing computer stuff. Not totally necessary, but it would've been nice to just look in the datastream to see if it was in closed loop or not. Or to see if any data items were out of whack. If you're doing enough of these old cars, I'd definitely recommend picking up an old scanner, like a Snap-On "brick." Also, these old computers have Keep Alive Memory (KAM), which gets erased when power is disconnected. When it's erased, it has to learn everything about the engine all over again, and just runs on default factory values until it learns. Especially important, since this old engine is probably worn out and all kinds of different from when it left the factory.

Closed loop wont engage until the engine reaches operating temp and the O2 needs to be screaming hot as well. Carbon fouled sensors get insulated from the exhaust heat so they get slow to come in range or fall back out of range at idle.

That was really cool to watch! Thank you for showing this great video!

As a computer nerd, making computers happy can be a real BITCH.

I bet he can fix a boat Radar like a Marine.......thx for the vid!

Extra contribution towards a multimeter we can actually read on camera 😀

Shango I have a 94 F150 I went through computer hell with. These trucks don't have heated Oxygen sensors, they are actually heated by the exhaust. That's why it takes so long to go into closed loop. The only other thing you have to worry about with this era ford is Codes 211-213. That's an issue with the distributor circuit and it won't let the timing advance. After chasing it for days (recapping the computer, going through the harness, changing the pip sensor and coil, then the whole distributor) and seeing no change I changed the computer and it went away.

Cast iron big blocks take awhile to warm up for closed loop. Good you can repair the ECU

You can’t beat a old Ford econoline especially one with a big block

I gots to have a closed loop after hearing that term 50 times in this video!

I should get a spare ECU for my car and recap it with the most high quality caps possible

Glad my 98 Ford e250 is running pretty well

I think is going to close loop if engine reaches temperature. Faulty temp sensor perhaps?

That’s good work, I’m always a little worried when I see long legged components in a vibrating environment, I’m not sure but maybe the caps could need some silicone to make them safe.

I did a bunch of oki data units in 90s Hondas.

After not having power, the temporary memory is purged and it had to run self diagnostics before it will try to go closed loop. Often these tests on the old OBD1 take 20 minutes or more.

GoldStar Multimeter reminds my infancy . That is modern day LG. Don't know LG making any testing instruments anymore .

Incredible work, and I've never seen inside one of these until you posted this video. Good tip on the ESR tester also. In the mid-90's, I had a rental RV that would just stinking quit about every 100 miles. I took the hood off of the RV and finished the trip. Those Ford EEC-IV units apparetnly had some temperature stability problems. Are the parts with the clip-on heatsinks transistors?

Excellent well told, You cover it perfectly

Looks like the shop has done some upgrades since you hooked that lawnmower up to the gas analyzer

As an old Ford mechanic, those old ECU's had to relearn. Some took a couple of hours to relearn.

KAM. Keep alive memory is lost when older Ford ECM's lose power. Some will set a temporary fault code for it until it relearns. Gotta love OBD1.

Well something new not a TV or RADIO but at least it is still nice waited all week long for my Sango066 weekly "fix" my video addiction. Sure worth the week long wait.

Interesting. I should get a Capacitor Wizard. I have a Blue ESR Meter and I hate the thing. Some things are better analog.

Early in the video you mentioned the electrolytics aren't really needed, presumably because the biggest filter is the car's battery, which is far bigger than any cap. I agree the battery should do all the smoothing the job, except that some or all of the ECU runs at 5 rather than 12 volts. Anyway if they want to maximize reliability the'd skip electrolytics entirely. I am sure in long duration NASA missions, like Voyagers 1 & 2, there are no electrolytics.

Even when everything is fixed, modified and performance enhanced on a Ford... it's still a Ford!

That cap tester is nice I want one now 😀 great video

I am amazed that the ECU module was not potted so it could not be repaired. 😮

Noticed at highway speed, the NOX was very high.

Some ECU's will only go into closed loop when the engine is at operating temp. others can be forced into closed loop by bumping the throttle.

When the car outlives the caps.

It is also likely that it wont go closed loop until a minimum engine operating temperature is read by the box

Where were you back in 2006 when the pcm in my Montero fried and I tried to fix it?

The trace to the left of the one you found that was open also looked suspect.

I'm not yet sure where my problem lies . I am blowing the maxi fuse in the number 9 position which is a 30 anp fuse . The truck is a 1996 7.5 460 with automatic E40D . Have you any ideas you might share to spread some light on things ? I would be glad to ship it to you if you're interested. This is a 109k truck and is above average for a gasser .

My hat is off to you sir Great work

Seems like you could use a scan tool that will get live data from the EEC-IV ECUs - might be able to pick up an older Actron unit with cartridge and cable (CP9110 + CP9112), for cheap'ish on ebay these days.

Can a PCM this be faulty if there is no leak. No burnt? If vehicle is misfire. Transmission shift problems?

Sweet job Shango

Can you do ECM swapping for a couple of years newer? Example using your 92 E350 install a 96 F350 w same engine size and transmission model?? great video!

@2:11 I can't tell the colors of the resistor on the bottom left of the screen. Can antine help me out?

And lol....the edelbrock performer is very wide band on my '82 it blazer. Miles of wire just equals a pita up here in snow belt rust belt chinada.

This one time I replaced my injector with a chinese ebay one. It was a good thing i had inspection a few days later because the CO was over 15

Excellent Video. I'm trying to remove the ECU from my 1995 E-150 Club Van. One mounting nut no problem the second one the stud keeps spinning can't get the nut off. I looked inside above the gas pedal and I see the computer. How should I hold the stud/bolt?

So where do you send an ECM to have it repaired ? Or where do you buy the parts to repair them ?

Something to be said for OBD1 ECM/ECU 'learning' after power loss and volatile ram is cleared. :)

This is a Ford...this is only a Ford....this is a Ford....this is only a Ford

Nice analysis and repair. Quite a few miles, if the odometer's accurate. What brand electrolytics are less prone to leaking like that?

Do you happen to know if there's a difference between 93 and 94 eec with a 460 automatic