Rough Idle?

[chartwigsen]

I have a 1991 MR2 with the turbo engine (3S-GTE). My alternator went out last week and I replaced it. It was driving fine all day but the next morning I went out to drive to class and the battery was dead. It took a bit more to jump start it. When it got going, the RPMs were dropping and rising from 1.5k-200. That was happening for about 45 seconds then it died.

[MR2Jedi]

After the alternator failure, did you fully recharge your battery?

[chartwigsen]

The 1st time? No. It died and a charged it back up and worked for a day. I havent this time either.

[MR2Jedi]

I'd fully charge the battery and then test it. Also, maybe double check the alt connections.

[bkftl]

If it doesnt hold voltage, or gets hot, its no good

[chartwigsen]

I just checked the alt connections and they are all in.

The battery holds voltage but I havent checked if it gets hot.

[MR2Jedi]

What was the voltage with engine off and with engine on?

[chartwigsen]

The voltage was 12.6 with the engine off and like 9 i think with the engine on. Broken alternator?

[MR2Jedi]

With the engine running, it needs to be 13.5 volts minimum.
Standard is 13.9 -14.3 volts @ idle.
I'd say you have a bad alternator. I would have it checked for free at Autozone, O'Reilleys, etc.

[chartwigsen]

Okay thanks man

[chartwigsen]

Well hopefully you will see this post, but i finally had a chance to tow my car back home and take a quick look at it. It idles better now, but its still rough, but it dies when i try to give it gas. I took a video of it and posted a link for it. Its on youtube.

You Tube

You Tube

[MR2Jedi]

Sounds horrible and way out of time.
I see the CHECK ENGINE LITE is on. Go to the diagnostic box on the firewall on the trunk side. With the engine off, get a paperclip and cross connect T1 and E1. Turn the key in the ignition to the ON position without starting the car. Count the flashes from the CEL. There will be 2 sets.
example: 5 flashes, pause then , 2 flashes = code 52.
Then we can look up the corresponding trouble shooting code and go from there.

[chartwigsen]

Alright I got 2431. Online it says "Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance"

[Apokryphos]

Originally Posted by chartwigsen

Alright I got 2431. Online it says "Secondary Air Injection System Air Flow/Pressure Sensor Circuit Range/Performance"

SAI is an airpump when on cold startups pumps extra air into the intake and effectively heats up the catalytic converter into closer operating temperature, where cat's have efficiency. It may also heat up the o2 sensors, where they read better.

since your battery is going dead, and since your car is also throwing this code (assuming you are reading it correctly) I hypothesize that your SAI pump is either seized up, or there is an electrical short powering the smog pump, as in, the power wire is shorted onto a ground, causing a loss in voltage, and less-than-stellar performance from your SAI pump.

Where did you buy your alternator? Not a used one I hope, or pulled from somewhere.
edit` now that i am hearing your car from the video,
how does it run once the car is warmed up?
Will it warm up? what else does the car do?
Is the sound coming from the engine? or is it just over top of the engine?
If you arent sure if its coming from the exhaust, check the EGR port if its a U.S. turbo engine

[chartwigsen]

My dumbass forgot to plug the MAF back in. After I plugged it back in it idles much smoother but there is still dies/does nothing when i try n get the engine gas. The alternator was new from O'Reilys (Only place that had it in stock w/o waiting 5 days to ship). I think the EGR is okay unless if im looking at the wrong thing. Its by the turbo?

I just let the car warm up and it is perfectly okay when heated up. Im thinking the cat might have shit out