ChrisWhewell

I'm lucky, I found a 99 with only 40k on it, basically in mint condition ! #0873. Previously I drove a '98 for 140k miles and a '97 for 120k miles, so I'm up to speed on maintenance aspects. Would enjoy reading about the Silver Arrow last 200, but as with the others, don't have or want a facebook account.

Maybe it melts everything. I'm pondering maybe that halogen lamp, but not so close. Then, use a magnifying glass to hit on every solder connection individually. I wish I could find a reliable ATYH memcal and just pop it in, this is turning into a long project

https://www.youtube.com/watch?v=HkO71G4wvo4

One answer is to obtain a male and female socket that matches the memcal, then, add wire between them so you effectively have an extension cord. plug the male into the ecm and mount in stock position. The female socket gets put into its own small enclosure, which can be remotely located at any desired place, like in the glovebox would be great. Then, changing memcal would be a one-minute operation. For removing eeprom from memcal, I'm thinking of a tiny flat copper bar that can contact all the pins on one side, simultaneously. Solder sucker is good, but I've also used solder blower, i.e., my compressed air nozzle. Heat the solder to melting, then pffft, blow it into oblivion. Mask off the SMT chip, and don't breathe the vapors. Otherwise, its the Padgett snip method.

Thank you. Yes, the age is a factor, I should probably get a new chip. , the original one probably failed due to age. Once I think about it for a while, I'll come up with a neat way to get the old chip un-soldered, and put one of those aftermarket ZIF boards in. At least the car is driveable, and its going to start to get cooler outside, so not having AC won't be as much of a concern. Thanks again.

Thanks, yes its 1990. I replaced the ECM two weeks ago. It sounds like I need to have the 27C256 reprogrammed

Thanks. I retrieved the file. thanks thanks thanks !! I'm calling the chip that is removeable, the EEPROM, and the other one that's not removeable, the smaller chip. Moates has a board one can removed the EEPROM from the memcal and solder his board in, which makes swapping EEPROMS easy. Maybe I have my terminology confused. I'm thinking of the two "chips" that make up the memcal, one is more removable than the other, and the removable one is what gets programmed, and the other one doesnt.

Thanks. That's the thing.... if the problem with the knock signal processing is on the small chip, then reprogramming the EEPROM won't fix that. I've already had the ECM in and out of this car 5 times, I am a professional ECM swapper at this stage, a position which I hope I can fire myself from soon. :)

Thank you. I'm beginning to wonder two things: 1) where on memcal is the diagnostics info for Reatta stored, is it on the eeprom, or the other chip ? 2) Same for the knock retard circuit, is that in the eeprom or the other chip ? Question 3, what I call the "other chip" that's not the eeprom, are they the same for all memcals ? What I'm suggesting is, a fourth question of whether re-programming the eeprom will solve my retarded knock retard problem i was having with the stock memcal. Knock counts were 5000-9999. If I knew absolutely that an eeprom re-program job would solve that, I'd do it in a minute, regrettably, I lack knowledge about the "other chip" in the memcal...

UPdate. I put the NOS memcal from a Lesabre with an LN3, into the Reatta. Started right up, idle is very smooth, smoother than with stock Reatta memcal. But... rpm gauge and eng. temp. gauge do not work. Also, if you remember my posts from 2 years back, when the rpm gauge isn't working, the AC won't kick on, so I have no AC. Also, in diagnostic mode, the engine data won't display. So, I took it for a spin. It definitely has noticeably much much more power. Therefore, it appears from seat of the pants that the knock retard of -17 degrees I was experiencing with the stock memcal, has been remedied by the new memcal. Wow, what a difference. Too bad no AC. Here is a riddle: "What's rarer than a 1990 Reatta ?" Answer: a good memcal for a 1990 Reatta. I found this interesting entry, concerning hard starts and memcals, unrelated to my issue but apparently there were a lot of memcals with problems. https://workshop-manuals.com/buick/reatta/v6-231_3.8l_vin_c_sfi/powertrain_management/computers_and_control_systems/memory_calibration_unit/component_information/technical_service_bulletins/customer_interest/906e8/

I blend, 20w-50 motorcycle oil with straight 20 weight. The motorcycle oil still has high zinc levels that my Reatta was designed for, I think api spec SG was the perf level in 1990

Yes its happened on my Reatta but its only intermittent and no code stored or tripped. One thing in my years of fixing cars, I've never once heard of a "service engine soon" light bulb ever burning out. Those suckers are invincible, I wish my tail lights were of such superior quality.

It would be nice if it makes the TC lock up later. All I want in the world right now is to feel the raw power of the LN3 unleashed, when the timing isn't retarded 17 degrees !! I promise to not hotrod around. lol

It should be a good learning experience anyhow. I saw on some camaro and pontiac forums, similar topic discussed. It was alleged that the same memcal was used on vehicles having differing axle ratios, and was asserted that it makes no difference. Allegedly the chip I'm getting fits the following: 1989-1991 Electra / LeSabre; 1990 Olds 98; 1989, 1991 Olds 88; 1989-1991 Bonneville. All with the LN3. Supposedly it'll be here Friday next.

yes ! Axle ratio on new chip is F17 (2.84), stock chip is F79 (2.97). So, I imagine, if it matters, the speedo might be off, or else it will shift later by a slight amount. Maybe this will be a poor man's performance upgrade, I never liked it shifting so soon anyway. I wonder how much of a difference it will make, if at all.......

I picked up a 16165848 for $31 off ebay. Literature source I saw, said it was from an 89 LN3 motor with an automatic trans. Its alleged to be new old stock. We'll see if it works, I can't think of any reason why it shouldn't. There's like 1000 different gm part numbers for LN3 modules, I can't imagine any of them are really all that different.

Thanks, I'm cooled off a bit now. There's quite a few NOS memcals available for 1990 LN3 engines with autotrans, I'll get one and pop it in.

Here's one reply I received Chris, the bad news is I don’t have any OEM Reatta mem-cals to sell you. But the good news is you don’t need one… Let me explain. The knock module circuit boards on these mem-cals are configured to work with a specific type of engine, regardless of what car that engine came in. However, the EPROM chip on these mem-cals contains programming specific to your Reatta. I have a way of loading the correct stock programming your Reatta needs onto a custom tuned chip AND I can supply you with a replacement mem-cal that should have a good knock sensor module on it. Cost for me to supply you with a replacement mem-cal and an adapter with bone stock ATYH programming on it will be $155.00 + shipping. If you want me to make any custom changes to the stock ATYH programming, add $55 to the above price quote. Shipping to a USA address starts at $8.00. That being said, I have to inform you that knock modules RARELY go bad on these mem-cals. So it is very likely you still have another problem causing your issues. And suspecting that, I cannot offer any guarantees what I sell you is going to fix your issue and I cannot offer you a full refund if it doesn’t – even if you return all parts I sell you to me.

This is out of hand, I've tried everything in the book, FSM says "replace memcal", yet I write to two long-time chip burners and they reply memcals rarely go bad. Can't seem to find any memcals, after all the time I put in to this car, its frustrating after 3 years it still has bugs. A carburetor and an HEI ignition system is sounding like a good option perhaps. The knock counts are constantly 9999, but sometimes drop to 5xxx. The motor at idle is quiet, and at idle there's no load, its inconceivable there is a single knock event happening. New sensor, new ECM, all voltages check out right on the code 043 page. Yet there is no 043 code set. I'm thinking, maybe to ditch this car, I have better things to waste my time on. Here's the real meaning of the 9999 perhaps https://numerologist.com/numerology/keep-seeing-9999

Thanks ya'all, yeah I tried the isolate the knock sensor early on, doesn't make a difference. Also doesnt matter if its grounded or not, its an AC signal. Also tried running it disconnected. I only get 4 degrees of KR that way instead of 17. However, the 043 code will occur when its disconnected, so apparently the wire from the knock sensor to the computer is not discontinuous. I appear to be at the very last step in the FSM for code 043, where it says "Replace Mem-Cal" :( The knock sensor is brand new. I even tested the old one, it tested good but I replaced it anyway Thanks for all the helpful suggestions

Thanks bro, the new ECM didn't cure my knock sensor problem, diagnostics is still gettting 5000 knocks per second and knock retard is 17 degrees, the max. I guess, next I'll try a new PROM if I can find one

So.. I got a new ecm. Pulled the old ECM, sweating bullets out there. The PROM says ATYH 8311 ............ arrgh. Not on the list of true Reatta proms as far as I can tell... geez. I searched and searched, can't find what an 8311 is from. Anybody know ? Thank you

https://www.theastrologyweb.com/spirit-animals/raccoon-meaning-symbolism

Wow, thanks. I currently have an intermittent 041 code. My heart sank when I read it, since I replaced the magnet 2 years ago. But, if I turn off the engine and restart it, the 041 goes away. Also, my AC will cut out unexpectedly, whenever it wants to. Answer is to turn off engine, and re-start. The problem I have is the ECM, I got it out of a second 1990 Reatta I owned. My original ECM had a fault, that the rpm gauge would not work, and when the rpm gauge doesn't work, the AC compressor will not kick on. So, I swapped the ECM from my spare car to the one I like best. It fixed the rpm gauge 100%. But, my instrument panel, once in a while now, goes black and gives the ERROR. Fix that by turning off the motor and re-starting. So basically, my car inherited the ECM faults in the one I'd swapped from the other '90. Who in the world would ever have imagined the rpm gauge not working, would not allow the compressor to kick on ?? So, I believe anything's possible on these cars re electrical issues. My knock sensor is reading in the 500 knocks range constantly, I diagnosed everything as in the manual's suggestion, the conclusion is a bad ECM. I'd like to replace it if I knew I could find one that is totally functional

91 year model is most desirable, to me at least. The cup holder is the deal maker. But, I also like the braking system on the 91's. As soon as one comes up near me with low mileage and at the right price, I'm grabbing it. I realize this may take years, but that's ok. The 1999 supercharged Riv. I just got with 40k on it, I spent 6 years looking for !! Buicks are awesome, some of the best engineers in the trade... I think my 99 Riv. is my all-time favorite, but still love driving Ms. Reatta. Just need to find a reliable ECM for it. Get the 91 for sure, you can always drive it down thisaway and sell it to me.....:)