So i swapped my engine in my 87 IROC 20 years ago. I got a 92 vette engine and wire harness from a wreck. Car ran great for many years. I've changed optis coil wires plugs......sent the ECM out for rebuild.....the only thing that improved it was I borrowed a PROM from a shop. Now it will at least start and drive fine up to about 45 or so, then it starts missing. I'd like to get a new chip. I thought i found a company that would do that for me. but the chip they sent wont start the car. I sent it back. They said they need to know " what computer operating system the ECM runs on" are there different operating systems? I cant imagine there would be more than 2 right? anyone with experience in this? Thanks for the help Pat

 

$DA2 and you probably want vats deleted

 

$DA3 is compatible as well, so yes you are right just the 2

 

ok so it's ONE or the other...they seemed so perplexed by this....so whatever one they did the chip for wasnt it? gotta go try the other one i guess. thanks pat

 

16159278 ecm ? Just the 2 languages were used. Maybe the chip had a vats issue if it was all stock.

 

they were asking me about the part number. where would i find it? I looked it over and didnt see one. this ECU has apparently been " rebuilt" twice. once before i got it 20 years ago and once earlier this year when i sent it out. pat

 

The service number is on the ecm case on a sticker. The memcal had an identification called a broadcast code a silver sticker on the memcal to identify usage. I’m not at home for a few days but might have a memcal

 

ok i might need it! thanks pat

 

Do you remember which company you sent your 1992 ECM off to be repaired by?

My friend has a 1992 Z07 Vette LT1 6 speed and it's also doing what you describe. Runs fine for awhile then when you get up around the speeds you talking about starts running like crap and missing.

Aside from the normal LT1 Optispark issues on these 92 Vettes we have the ECM issues, grounding problems, wiring harness issues and not to be forgotten these engine also have the retroactively defective by design RP Multec fuel injectors too that plague our 89 to 92 TPI engines in the F-body cars except the LT1 engine use the 24lb version.

 

I had the ECU "rebuilt" by SIA electronics, 730 North Minne St, Tilden IL 62292. they charged me like 400 bucks. coincidentally when on ebay i found another service provider...same street different box number that was saying they would do it for 200 bucks....former employee? who knows.........interesting that your pal has the same issue. he also has an LT-1 engine?

 

Yeah as he described it to me it seems to be the same problem or close to it. 1992 LT1 6 speed.

 

Just curious if you got it figured out?

 

I sent the chip back and i'm waiting to see if the guy can reprogram it......they arent great about returning phone calls...very disappointing.........in the meantime i drove it at 40 mph to get it inspected.........I'll keep you posted....i hate to give up on this engine......i dont have time for another "project"

 

I looked and don’t have any more 92-93 memcals. But if they can’t program what you send it let me know I can help if you get it back. The 92-93 isn’t to hard to find on eBay the memcal that is. Unlike say tbi and tpi it just has a chip and knock filter no lump home netress resistors on the memcal. Any memcal from 92-93 manual or automatic can be programmed to work.

 

I might eve buy one from an automatic. cant see why that would matter to my 5 speed?

 

Timing, idle speed, iac logic slightly different

 

If i get desperate? maybe?

 

It will work yes, just can be improved on

 

https://ebay.us/m/khzWJ0

 

OK so here's an update on my Bad running LT1. yes it still runs bad. I sent my original chip to a guy who checked the program on it and said it was fine. I had him copy it over to a different chip and send it back. car still running bad. I bought a used ECU from ebay from a junkyard. it's out of a wrecked 93 vette. It had a custom chip in it from a speed shop in NC. I tried my chip in it. ran bad. i put the custom chip back in it, ran better but still bad super rough like it was missing, smelled rich. So going back to square ONE i decided i would check/.change the plugs. HEADERS! after 3 hours i had 3 changed on the drivers side. they looked fine. I'll keep going...but im thinking this isnt the answer. if I could drop this car at a smart speed shop i would trailer it there. My local speed shop , that did the original tune on the car isnt interested. they say it must be the Opti spark. I have changed it twice. once with an expensive one, once with a cheap one. runs the same.........so thats where it's at.........sitting on a lift in the barn. Pat

 

Have you tried to datalog the car? Get an OBD1 to USB cable, download tunerpro and the associated $DA2 .xdl file, then start datalogging it.

 

Im probably going to have to do that. is "tunepro" available online to purchase? SO im adding that to my laptop, then watching it run to see if it will tell me what's up?

 

Or just get a scan tool on it. One way or another, you need to be able to "See" what is happening. It's possible that you got two bad Opti's but incredibly unlikely. You could diag that w/a scope, if you have access to one.

 

www.tunerpro.net

https://shop.moates.net/products/aldu1-and-cabl1

 

more than that. You can post the data file here and we can look at it as well.

 

Typo in my earlier post...

You want the adx file, not the xdl file. The xdl file is actually the log file that gets created by tunerpro, which is what you'll post here for us to look at.

The adx file is the ECM definition file that you need to get TP to connect to your ECM.

i created a TP setup "How to" document. Let us know when have everything and I'll post it.

 

I think I will get a new laptop. My old one has too much stuff on it. but i'll be back when i get some data. thanks for the advice. pat

 

OK ordered the cable....lap top on the way. thanks for the input. pat