tintmandevin

Car died suddenly while driving yesterday. Pulled over and restarted but died again after 45 seconds. Called rollback. Once home I checked everything I could think of. Wires, rotor, cap,tps. 54,new iac,new coil, regrounded and cleaned grounds, new fuel pump,new ecm, etc. Blew away a harley right before she died. Obd says eprom problem. I put old stock eprom back into new ecm. Ran like a banshee right up til then. Does an eprom just go out suddenly? Mostly stock but k+n and open exhaust. Really bummed out. Love my vette. I know lots of threads suggest performance chips but I'm happy with stock eprom. Should I go to dealership and buy new stock eprom. Any help appreciated. Thanks in advance.

JackDidley

They rarely go bad. They do have problems if no seated properly. May try taking the eprom out and reseating it and see what happens.

tintmandevin

Today I pulled out ecm and checked eprom. It is the original stamped "delco BUA 1728" blue and brown. Looks like new. Tried resetting it in place. Nothing. Seems like no fuel maybe. Has new fuel pump and filter. Pressure regulator??? WTF. One minute fine, next minute rollback picking us up!?! Maybe MAF? Relays? Old car still has AIR pump and egr. All looks good. Cleaned my key anyway. No SES light before she croaked.

Benny42

I agree with Jack, check the fuel pump relay and injector fuses first. Its usually the
simpler things that fail, not the computer.

Cliff Harris

Did you get an error code 51?

They're pretty robust and it's hard to damage one.

There are none left. If you can find one on eBay or some place like that you are looking at probably $200 or so for an original stock EPROM. That said, many people can program a new EPROM for you for a few dollars.

tintmandevin

I tint windows. I'm a far cry from a mechanic. Thanks benny and jack for your much needed advice. I will check the relays and fuses. The only fuses I have ever seen are on passenger dash side. Are there some more I haven't found yet? Failing ecm? Came from Advance Auto. Refurbished in Mexico. $70. Maybe has warranty. Idk. MAF looks like some silicone is coming loose underneath??? Ill order new MAF relay and burnoff just for kicks. Idk anything about the fuel relays if any. Searched long and hard for any loose connections or chafed wires. Car is in great shape. Everything looks new to me even though its 29 years old. Always garaged. Any more advice greatly appreciated.
Devin.

JackDidley

Is the SES light on ? Check codes ? Check fuel pressure ? Also look at the harness where the FP relay plugs in. You may find a wad of melted insulation like I did a few years ago. I dont know why I was not having problems at the time but it looked bad so I fixed it.

MrWillys

Are you getting one of these codes?

http://www.chevythunder.com/codes_5152_55.htm

You cannot purchase this memcal at the dealer any longer.

tintmandevin

Code 51. Eprom. Looks brand new. MAF? Good fuel pressure. Smells gas fumes when trying to crank in garage. Temp gauge? Always runs cool by digi gauge 180-215 in traffic with ac on. Cooling fan comes on at cold start no ac on?!? Fuel cap?? Doesn't seem to have as much vacuum as before when filling up. Bad gas??? Bummed out. Need for speed outta control. Somebody gotta know. O2 sensor? Still running emissions and AIR pump. Thanks again guys for your help
Devin

MrWillys

Code 51 says replace memcal, and if that doesn't fix it then replace ECM. However, because the ECM has just been replaced it is suspect. Both these items rarely fail, so good luck to you!

tintmandevin

Did replace ecm again. Warranty. Used old eprom again with terminal grease. Got new icm. Replaced that and cleaned plugs throughly with wire brush and alcohol. Put everything back together and she fired up and is currently running better and more power than before.
Thanks