Replacing 95 Metro Computer

[MetroN00b]

Hello everybody,

I recently tried to use a computer diagnostic tool on my 95 3 Cylli Metro, but it can't get a reading. I have been getting pretty bad gas milage, so is it possible that my onboard computer is broken? Would I be able to use a computer chip from a 91-94 Metro in my 95? Thanks for you time.

[SeanMurphy]

What kind of diagnostic tool did you use? Only the 97 and up Metros were OBDII compatible, so one of those scanners wouldn't work. If your car runs, and you get no engine lights, chances are the ecu isn't broken. I'm not entirely sure, but I doubt you can use the 91-94 metro computer on a 95. I think there were changes to the emissions systems between those models that makes the computers incompatible.

[MetroN00b]

Thanks, I appreciate it. I didn't quite understand about the engine light can you explain a bit more? Atleast I know I can't use an older computer in my 95, that was my main question.

[SeanMurphy]

On your dash console whre the spedomoter is, there is a light marked "Check engine" or "service engine soon", if this light isn't lit up, chances are the ECU isn't failing. This light comes on when the ECU detects a problem from sensor data. If the ECU were failing, I'd expect it to be flashing all kinds of engine errors. Additionally, if the engine runs, the ecu must be doing something. If it were totally gone, it wouldn't work at all, as the ECU does work in keeping the fuel injection and ignition in check.

[Crvett69]

there is a extra place in fuse box thats at slightly different level with no fuse in it. if you put a fuse in it the geo check engine light should display any codes it has collected in last 50 starts. just put fuse in and turn key to on position, check engine light will blink codes out. should start with a code 12 . will blink each code 3 times

[Crvett69]

if you do end up needing a computer i just picked up a wrecked 95 metro with good running gear and computer

[mcalvo]

MetroNoob:
High milleage could be a symptom from bad piston rings. I would recommend you to check each cylinder pressure. Should be 170+ on each (185 optimum) lower than that could mean bad ride in many ways.

Hope this helps,

MC

[MetroN00b]

Cool. I appreciate the help people. I was really tired when I asked what the whole engine light deal was about. After rereading it I was laughing. Sometimes the obvious is hard to see. Happens to me all the time. I'll check out my piston rings in mechanics class tommorrow.