Hot start/ surging at low RPM

Last week the batt light came on while we were driving downtown. we had a few errands so my girl stayed in the car while I ran inside as I was afraid It maynot restart. Apparently while I was inside the car revved up to somewhere around 2,500Rpm when I got back it was down around 2,000. I flicked the trottle a couple of times and it dropped to around 1,200. I then put it in gear and it dropped to 800 RPM. after driving for a few minutes on the highway the batt light went out and we went to Autozone. A test of the batt showed bad batt. But a test of the alternator showed bad diode we replaced the batt. and the light stayed off ( I thought maybe it was some faulty test ). So a week passed and all was well until yesterday we were running errands again ( Damn those errands! lol) and suddenly it didn't want to start. It was cranking like normal but not firing. and when we would drive it it would surge at cruising speeds Say 20-45mph it was very light surging but you could feel it. And guess what came back on today. now on a fuel injected car I can see the injectors/computer not seeing enough voltage to operate properly but mine is carbed...any Ideas. and Yes I'm going to replace the alternator this weekend. Thanks guys and gals.

My first thought is that it's time for a carb rebuild, but definitely get the voltage issue worked out first. I don't put a lot of stock in those free tests from Autozone, etc. It's much more cost effective to buy a $15 multimeter and check the system yourself. That way you don't end up buying parts you don't need. If the alternator is putting out 13-14v while running, then it's probably okay. If the alternator checks out, then check the voltage on the battery with the car off. If it's much less than 11v, take it out for a run down the freeway and check it again. If it's still low, then the battery needs to be replaced. Let us know how it goes.

I had a similar problem, suddenly the alternator light comming on intermittently. It was not an intese light, the battery simbol in the dashboard was like faded away everytime it came on.

It was night and I also saw the head lights turning off for a millisecond every time I pressed the brakes.

Got home and found one of the negatives wire loose, not the big connector to the battery, but a smaller size wire that is connected with an eye terminal to that big (usually cooper) connector. It isn't cooper in my car...

It usually is cooper that gets you into trouble. Stay away from him! hehe

Don't replace it yet. Auto stores are in it for the $$$ #1. If they can they will try to sell you something. Although more often I've had parts test good when they weren't. As said above. Test it yourself.
Voltage problems? Add more grounds! It's amazing how much this can help these cars. There's a how to on it on this site, but basically just add a few from motor to frame in a couple places and your good to go

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Originally Posted by Dr_Snooz

My first thought is that it's time for a carb rebuild, but definitely get the voltage issue worked out first. I don't put a lot of stock in those free tests from Autozone, etc. It's much more cost effective to buy a $15 multimeter and check the system yourself. That way you don't end up buying parts you don't need. If the alternator is putting out 13-14v while running, then it's probably okay. If the alternator checks out, then check the voltage on the battery with the car off. If it's much less than 11v, take it out for a run down the freeway and check it again. If it's still low, then the battery needs to be replaced. Let us know how it goes.

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I work at Autozone and the battery/alternator tester that we use is an autometer tester. It puts a load on the system to properly test it unlike a multimeter.

I've never given a customer bad advice or false information to try and sell a part, and if I was ever accused if it I'd kick their ass out of the store. None of us work on commission.

Also, just because the alternator puts out 14v doesn't mean that it's good. You have no idea how many amps it's putting out, so it could very well be bad. Most of the time I've had them test bad is when they're still okay on voltage, but not putting out near enough amperage.

Calm down geez......

Not everyone is as good a person as you :)

Bad grounds can cause some crazy things to happen and if it was tested in the car that might not be the actual problem. Of course i don't know the exact mechanics of the alt,but im just trying to save him some possibly unnecessary spending