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The engine computer
Thanks for that link.

I Intend to eat the 50$ core charge of newly reman'd Cardone ECM, which is supposed to arrive tomorrow.

Supposing the engine fires right up with it, that will leave me 2 cores, the original, and the recently failed 15 year old Cardone.

I need to try and replace the capacitors on the original. It's gonna happen. If I fail, then I will send it off to a professional.

That leaves the 15+ year old recently failed cardone.
Could return it to Autozone for 50$ core charge.

Could keep it as a core and try replacing all capacitors trick, and if that fails, mail it off to the Pros so I have two back up ECM's.

Everything else on the van should have easy parts availability for a while to come, and everything else seems mechanically sound. Just got the best fuel economy ever on a cross country jaunt and it burned less than half a quart of oil in the 5200 mile round trip.

Been wanting a backup ECM for a long time now, Should have tried replacing the capacitors in original already.
Need to shop for some conformal coating to pot thenew Caps, assuming I am successful.
[-] The following 1 user says Thank You to sternwake for this post:
  • rvpopeye (03-09-2021)
I doubt they check the caps on a core. But timing on that could be problematic....
Stay Tuned

Weirdo Overlord  YARC 
15 "Stinkin'Badges"  a "Full Monty Badge" 2 "Just Ignore Me" clusters  10 "Pine Cone" clusters  , one "Stinkin' Badger" and 8 of the coveted "Flying Manure Spreader"awards
(What a "Stinkin' " honor !)
While it is not yet in hand or much less installed in van and running, I've got to give a hand to Autozone.

This reman ECM, ordered on a Sunday, will arrive today, Tuesday, via fedex, for about 40$ less than the next cheapest vendor, who would 5 day USPS it. Napa would have outright doubled the price of what is likely the same ECM shipped from same warehouse in Philadelphia.

Hopefully the ECM is not a Dud.

I ordered and returned a dud in late 2014, before depotting the 14 pins and resoldering them myself in early 2015. Can't recall who I bought it from, might have been an Flea bay vendor.
I replaced the wire from ecm to coil negative. 12 awg...tinned marine wire replacing 18 sae gauge 30 year old wiring.
One diagram in factory service manual is wrong. In terms of the 14 pin connector. They mixed up  1 to 7,  with 8  to 14 .
Glad  I double  checked before employing wire cutters.

I decided against hooking the aftermarket tachometer wire back up... Just in case it is compromised along its length somewhere.  Did not want to pull apart dash at this point.

Engine coughed twice then fired right up with new ecm, which arrived 46 hours after placing order.

Newly arrived ecm has obviously new capacitors along with several other newish looking mystery components.

Here hoping the 'new' one is also good for 15.5 years.

Groceries gotten. And a bellyfull of take out Mexican food. 

Overdrive kicken in en route as hoped. Did not get to 47mph to see if lock up engaged.
Fantastic,  our technical manuals always contained many errors in the writing and diagrams.  You always have sounded like you put a lot of thought into every project you take on.
Ir's a shame you can't even trust the source material completely.  Now back to enjoying your hepa filter and most of all Fionna and surfing.
So I inspected the recently failed ECM a bit closer.

Pulling the potted  14 pin board from its plastic tub/cradle, I get to see the backside of the 14 pin connector that I reflowed the solder upon in early 2015.

I recall being so hesitant to take on this job then,  as my soldering skills were so much poorer than today, and in 6 years I might skoff at my soldering skills of today.

Anyway, the one pin whose wire I just replaced going  from ECM to Ignition coil (-), showed just how unhappy it was. It got so hot it burnt the liquid electrical tape I applied back then.

I do not believe this failure to be from a shitty soldering job.  I believe that the tachometer, when it lost its dedicated ground and worked intermittently for the 2500 mile drive eastward, screwed up this whole circuit, frying it.

The ignition coil drive transistor is a Motorola 5206377.  The pic below  is from my newly reman'd Cardone ECM, I cannot see the part numbers on the older ECMS.

One of the few hits to this part number come back with this very relevant hit:

It looks like if I were able to acquire this unicornium transistor, or a more modern equivalent, that after depotting it, I would need to melt 4 solder joints simultaneously, and keep the solder molten while unscrewing two phillips head screws.

This does not appear to be anything an inexperienced  DIY type with too  little practice, and no desoldering tools, can really expect to achieve.  I'd likely screw up the traces trying. 

This ECM might be the candidate for mailing off to the Pros.  I am not sure the transistor itself is fried, but it seems likely.  If this transistor is unobtanium with no modern equivalent, then it cannot be rebuilt, and would be a waste of shipping to some re builder.

Looks like the trace, one of the fattest on the circuit board, is also fried near the pin






Anyway there is no rush. 

 I want a Backup ECM, for peace of mind, but the newest cardone seems to have a lot of components recently replaced, and they seem to last 15 years.  This failed one in most of these pics, was a forced failure.  I really believe my foolishness at not remembering to re attach a new ring terminal to the Tachometer ground wire, when I broke it,  is the cause of failure.

Aim at foot, 
take careful aim,

It's amazing how that works.

The ECM actually has a air snorkel that splits off to the main engine air intake.
the engine sucks air through the engine computer, and a lot of dust.

My snorkel is compromised, no longer fitting tightly at the ECM, as a result lesser air airflow through ECM was occuring.

I have a new 1.5 inch flexible aluminum hose and a 3 inch hose ntend to rebuild the Snorkel which is 2 1/4 inches diameter stock 
 Might have to add some filtration.

I can increase heat dissipation and airflow for the Newly Reman'd ECM.
The existing air cleaner snout is not going to mate nicely with a 3 inch diameter hose.

A junkyard trip could be beneficial.
I made the new cold air intake, and on the initial test drive, it only felt like there was a positive noticeable difference when accelerating a bit harder at higher rpm.

The second drive, the whole van felt noticeably peppier throughout the rpm range, to the point I want to adjust the throttle rod slightly and move the transmission shift points as it seems to start pulling significantly harder at about 2400 rpm, then up shifts, and a 2750 rpm shift would be more desirable, if accelerating hard were something I did on a regular basis. I'll have to see. I have it set to shift more for MPG/ light acceleration.

It certainly feels different, and having been driving the same vehicle for 20 years, it is not just placebo effect.

The first drive after resetting the ECM, is usually a bit weird as the ECM is learning the engine, the second cold engine start after resetting is always smoother, especially when still below full temperature.

The original intake was black accordion style and is 2.5 inches inner diameter. I basically cut off the accordion portions, and slid the 3 inch ID flexible aluminum hose over the 3 plastic portions and sealed it. One joins with the air cleaner snout, one is a Y shape for the 1.5" offshoot to the ECM, the third is where it attaches to the radiator support and pulls in air from in front of the radiator.

The section of accordion hose closest to the air cleaner snout, had split long ago, and I apparently just used electrical tape and covered that with Nashua Flexfix 555 tape, and forgot about it. The next heat cycle, the stretched E tape compressed the accordion down to ~1 3/4 inches diameter, from 2.5", but showed no signs from having done so from the exterior. It was a significant choke point, that was only visible by shining light inside the pipe, and I remained blissfully unaware of it, for years.

The seal with air cleaner snout was also pretty poor, so it was able to pull in a bunch of heated underhood air. I was noticing this with my temp sensor in the air cleaner housing. With blend door dropped at higher throttle levels, climbing mountain ranges, no heated manifold air allowed, the intake air should be close to ambient temperature, but I never saw it get less than than 10 degrees above ambient.

I plan in wrapping the new intake with some 5mm SmartShield, the reflectix like product with a foam in the middle rather than double bubblewrap. This is likely a waste of material and effort, but the intended purpose is to help keep the intake charge temperature down at higher throttle, and a bit of noise cancellation.

The new Intake, with most of the plastic accordion pipe removed, is slightly louder. There must have been some noise cancelling going on with that design, at least compared to the aluminum flexpipe.

The air housing temperature sensor, which controls the vaccuum to a blend door which tries to keep the temperature of the air entering the engine, at light throttle, at 100F average, sometimes maintained 102F +/- 4f, and other times was 112f +/- 30f.

I tried to figure out when and why sometimes the swings were small and other times wild, but never came to any conclusions.
One theory was the bend door, allowing in manifold heated air on the bottom, with ambient air riding atop was not thoroughly mixed by the time it got to the sensor on the other side of the round air filter. The sensor intake is the same height as my thermocouple sensor, so perhaps the vacuum controlling sensor was also seeing hot/cold air and unable to maintain a steady intake temperature.

Anyway there are ways to test some theories, but I figured the best pace to start was after the new cold air intake was in place. The times I noticed the +/-4f swings, the gas needle seemed to drop slower than those times when it swung 30F on either side of 112f.

I've not yet returned my temp display to see what the intake charge is with the new cold air intake, but if the theory of layered hot and cold air is valid, perhaps some vortex generation within the CAI would mix it together better and allow a more homogeneous temperature charge, and perhaps help the highway MPGs even more, which is the goal.

Thinking about the vortex generation within the CAI, leads me to the older scam 'tornado' devicesmarketed to the fast and furious tuner crowd types. While these devices might cause some swirling and better mixing of air and fuel into intake manifold, and the4y might not, but what they do do, is add restriction to the flow when placed inside the CAI.

I was thinking if I add one for a 2.5inch pipe, suspended inside my new sections of 3 inch pipe, that I will not be creating any additional airflow restriction, but could benefit from the vortex generation and the elimination/mitigation of potential laminar/ layered flow, that reaches the air cleaner vacuum modulating sensor which lifts and lowers blend door.


I think I am going to try it, even though it is likely a waste of time and money effort and materials.

But if it bumps up my average MPG 0.25 mpg it will pay for itself the next time I drive cross country.


The One ECM rebuilder Blacktank linked, SIA electronics, that has the 129$ advertised fee, also, further down, has a 90$ 'test fee'

Quote:Test Fee:

Not all electronic parts are repairable. Sometimes the damage is far too great to fix. If you part is found to be in good working condition there will be a test fee of $89.99 issued to you, the customer (Return shipping is still included in the test fee). The remainder of the original price charged will be refunded. If your part is found to be not repairable there will be a shipping charge of $13-$15 for shipping and handling.

It seems intentionally poorly written, and confusing.

But, that fee brings it right in line with all the other companies which rebuild the ECM's.

It would be cheaper to buy another AutoZone sourced Cardone reman, to have as a backup ECM.

I'm also making a cardboard template that wraps around the ECM. I intend to insulate it with the SmartShield/reflectix, as it rests on firewall directly above engine and heat is the electronics killer, so any mitigation of wild temperature swings, and reduction of maximum temperature, is beneficial. Adding heatsinks to those already present within, might also occur.

The ECM location is now directly over my still unwired, non functioning Nippondenso second alternator. This dual internal fan alternator sucks in air from either end and expells heated air around the perimeter.
This perimeter is directly inline with the ECM and would add to its heat loading, so reflecting/redirecting that heat has to be beneficial for longevity/reliability.

There is airflow through the ECM. The ECM air intake is sucking in underhood air temp. I have sections of aluminum hose remaining to pull in air from somewhere cooler, as opposed to air heated from radiator. There is apparently no sensor inside the ECM, trying to determine ECM / underhood air temperature, so this rerouting of ECM intake air should only be beneficial to the lifespan/reliability of the ECM.

I lucked out that mine failed within the free AAA towing range the day after completing a 2600 mile journey. I am also lucky that a replacement ECM can be had for a 30+ year old vehicle.

But I still want a backup for peace of mind.
2 days is a pretty incredible delivery time, but it would suck to have to be waiting in the middle of nowhere for it to be delivered.
That vortex piece might be just the ticket or an "air dam" to channel/mix air at the sensor may come in handy. Something along both sides from near the outer edge of the air cleaner housing up to really near the air cleaner. Just a thought.

I am still liking my smart shield application. It seems much sturdier than reflectix too although I have had a few bubbles pop up on the sunny side.

2000 Roadtrek 200 Versatile "The Beast" (it has been tamed hopefully)  I feed it and it doesn't bite me.   Angel
Reflectix bubbles can be popped too.

I got some white sided 5mm Smartshield, but have not closely examined it, yet.
My other smartshield is holding up OK, but is losing some of the aluminum in near the edges where it gets bent the most during install/removal, nothing some Flexfix tape cannot fix.

The simply liked the looks of the vortornado thingie, but was thinking about some other means of mixing hot and ambient air before it passes through the filter and reaches the sensor.
The little stick on vortex generators/diffusers seen on Some Subaru WRX's and similar vehicles, and even one outfit making them for surfboards, were considered.

With the vortexnado thingie suspended within the larger pipe, it should not add any restriction, and could, perhaps be beneficial, and was the cheapest potential solution to a perhaps non existent problem.

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