1g alternator changed and now wont run right

[east_bay_r6]

im new to the forums.
i just picked up my 2nd dsm which is a 1990 eclipse turbo.

anyways i cant figure out what to do now. my alternator died so i replaced it today and now the car will not run right. i will jump start it and if i try to rev it or drive it, it just backfires like crazy and then dies.

i dont know what to do now. i made sure that there is no boost leaks, exhaust leaks, vacume leaks ect...

any help would be appreciated thanks

 

[Talon2139]

So it was running fine before you changed your alternator?

I would also say that even if there was a boost leak it would still run, or idle. Would be really rich but would still idle; at any rate it sounds like you might need to check your timing.

 

[steve]

You sure you plugged everything back in? Forgetting to plug the MAF in will do that.

 

[1gDSMike]

Did you make sure your battery was fully charged up before starting it??
If not you might of killed the new alternator already.

 

[steve]

Or a blown alternator fuse and the car is trying to run on low battery voltage.

Put a charge on the battery and try in the morning.

 

[east_bay_r6]

so it was just the battery that wasnt charged. i charged the battery and put it in and it ran perfectly again.

 

[steve]

That explains why it ran poorly but you still may have a problem with the charging system.

Hook up a voltmeter to the battery and measure the voltage with everything off, and again with the car idling, and yet again at idle with the lights on and ventilation blower on high.

If the voltage while the engine is running is less than 13.6v you aren't charging the battery. First thing to check is the 80A alternator fuse bolted down in the front fuse box.

 

[wondersb]

It might be a good Idea to do a load test on the battery. I you don't have a load tester turn everything on in the car, lights, fan, etc, and start the car with the volt meter hooked up. If it gose below 8 volts its a good sign of a battery going bad.