Oh man. Well, after I swapped out the ignition module with a new, identical GM part (trying to fix code 42) I put the distributor back together very carefully. After that a very short test drive. I then noticed a heated or cooking circuit board smell in the cab. When I got out I checked the Battery compartment and found the metal case to the ECM to be very hot and emitting the funky circuit board smell. I removed the ECM and upon removal of the metal case I found a brownish goo that had oozed from from one of the capacitor circuits. Well any ideas on what to to next? Why did this happen?? Trying to locate a new/refurb ecm seems difficult and spendy. Read a little about 1984 C4 ecm as a swap or upgrades. Dynamic EFi looks interesting. I'm open to any suggestions. Thanks, Jeff

 

Autozone sells reman ECM for these cars for about $90.

 

Should have added. If you're worried about getting it from "the zone", don't be. Most of the parts nowadays from all the different parts store are the same in different boxes. Most reman ECM's are Cardone. Also, the fact that it seems to have "fried" the ecm points to an outside source. If I were you I would test every circuit, sensor and solenoid to and from the ecm before plugging the new one in.

 

general rule of thumb is if you do something and something else goes wrong, you just did it. although sometimes electrical stuff just decides to die. i was replacing the same capacitor in honda trans modules i was buying at auction cuz they had bad trannies. the 84 ecm is supposed to be faster and better.PM Buccaneer. this is his wheelhouse. tbichips.com also messes with this stuff.

 

So - Electrolytic Capacitors have a "lifespan". Most of the Electrical Engineers I know put that lifespan somewhere in the 20 - 40 year timeframe. They typically don't go bad all of a sudden - but they slowly deteriorate over time. At some point they may get to the point where they can not withstand the voltage that is applied to them, and just fail. (And BTW - High temp shortens their life significantly)

http://www.elna.co.jp/en/capacitor/alumi/trust/


Its entirely possible that is exactly what happened to your ECM.

I took a quick look - Rock Auto shows the ECM for your car is out of stock - (and Yes - it's from Cardone). But it seems that CAR ID has one, and I suspect other sources will as well. Price looks to be a bit over $100.

https://www.carid.com/oe-replacement...r-1225500.html (Please triple check that part number if you're going to go this route)

OR - you cold decide that you are going to either ditch the factory EFI system, and go with a more modern set-up - or go old school and mount a nice Holley 4 BBL carb on a nice aluminum intake. Both of those options are significantly more expensive than simply replacing your ECM,

 

Translation/ tested.
No one rebuilds these. They just screen them.

 

OK, the fact that your ECM went south sucks for sure and I feel your pain. The 84 is an option, but is not any faster or better than the 82...period. Dynamic EFI is another option and you could go with something like an 1227747 or 1228746 ECM which are from the late 80s trucks and the early 90s F-bodies. Unfortunately, you WILL have to laptop tune the motor at that point. The up side is that it could run a bit better with the right tune and I do have the HAM board to do the interface between your stock harness and the newer style ECMs so you don't have to do ANYTHING to your stock harness and HAM is all installed by Bob at Dynamic EFI. Bob does great work and is very knowledgeable about ECM's.

If it were me, I would go with a replacement and see if you can get away with a replacement and not have an even bigger issue going on. I sold a HAM to a guy in Jersey for an 82 and fixed all his issues and then had to tune the motor. The last I heard from him he had worked out 99% of the bugs that he ran into and the car was running rather well. Unfortunately, I do not know the final outcome of how it went in the end. The EBL Flash II by Dynamic EFI is a VERY good product and developed by Bob. I run the EBL Flash in my 82, 383 motor and it works great with zero issues. If you would like to talk about this, PM me and I will give you my number. Good luck whichever way you decide to go.

One last word on a replacement ECM. MAKE SURE YOU MARK YOUR CURRENT PROM BEFORE REMOVING IT ON ONE END WITH MAYBE SOME PAINT OR MARKER. If you install it backwards in the PROM holder of the new ECM, it WILL fry the PROM as soon has you turn the key to ON...instantly. Just a word of caution there about that. If that happens, good luck finding a new stock PROM.

 

A friend had the same issue with his 82 a few years back. A local chevy dealer had an oem one sitting on the shelf. Did he get lucky...most likely. Couldn't hurt to call a few dealers.

 

This had to have been a very long time ago. I can't believe that any dealership would have that just lying around on a shelf in 2020, on the shelf for 38 years?

 

You guys are truly the best!!! Such great advice....Can't thank you all enough. So, this incident has forced me to become a student of the ECM and all the options out there for the '82 and YES!!, you fix one thing and literally something else fails. This time with in about 3 minutes. I'm finding that out very quickly. I guess you can expect this for a 38 year old vehicle. I checked carid and just about everybody else in the country it seems and they are all out of stock of both 5550 (82) and 6026 (84 at) ecm. The Dynamic EFI option looks to be an option (maybe my only one) although spendy. Meanwhile if anybody has a line on a stock 82 or 84 please let me know. Thanks, Jeff

 

Buccaneer,
Not sure why it is so hard to believe....Internet search found this story very quickly.
http://www.superchevy.com/features/s...dunn-chevrolet

 

All I'm saying here is that it IS extremely rare to find something like this at a dealership, anywhere. That story was from 2009, the dealer closed in 2007...today is 2020. Mmmmm... Yep, I find it hard to believe. It's like a barn find, they are far and few between, but give it a shot, you may be very lucky and find Jeff a working ECM under $100 with your Internet skills.

 

Right it was 11 years ago but........there were nos parts from the 40's,50's and 60's. Please post evidence that it is rare. I would like to see that evidence. Not sure how anyone could say what a dealership has in the back room. But as I said in my first post I did think he got lucky.

 

Thanks everyone. I was able to locate an 84' ECM at a junkyard using the interwebs. We'll see what fails next. Cheers, Jeff