H8ntrnks

Hey there, hoping someone can shed some light on a situation im having with a recently picked up 77 L82 automatic.

Has a couple of aftermarket add ons. Edlebrock performer series carb, Performer eps intake, roller rockers.

Super clean car, recently restored. rebuilt motor and trans. Bought it and drove it home about 1.5 hours away. Ran like a top, no issues what so ever. Purchased on the weekend so had to wait to get plates. Car sat for 2 days with periodic start ups. Everytime, it fired right up and ran perfect. Today, take it out and fires right up. Backed to the end of the driveway and it seemed to stumble a bit. Gave it a little gas and cleared right up. Drove it about 10 minutes down the road perfectly. Came to a stop sign and let off the gas. Car died. Tried starting, rrrrrrrr rrrrrrrrr click click click. Dead battery? Passerby stopped and let me jump it. Fired up, seemed to run fine for a second then it was struggling to stay running. Had to keep on the gas to keep her going. Let off, dies right out. Left the house with a quarter tank maybe slightly more. Was heading to the gas station.

Towed it home. At this point, gas gauge is just above empty. Tested alternator. Alternator is charging and reading fine. Tested battery, tested fine. Brand new battery.

What are your thoughts? New to this platform but mechanically inclined across other platforms. Looking for some pointers or maybe places to start or check. I can try and provide any more info if needed. Thank you in advance for any help. Im hoping to learn a lot from everyone on here.

-Steve

H8ntrnks

I apologize, thought i posted this in tech/performance. Feel free to move if necessary. Newbie mistake.

ntfday

Sounds like a fuel problem to me. How is the fuel pressure?

Rky Mtn C6

What gas ya using? When I first got my 78 L-82, I put premium in it and it kept dying. Was told they're made to run on regular. Started using regular, and haven't had any problems since.

jlpskydive

Nothing personal here, but that's just silly.

Back on topic... Might have trash in the fuel filter, fuel pump might be going bad, hows the spark??? Check for leaks in the rubber fuel line segments. My 78 ran great for a couple of days and then I woke up to a house full of gas fumes. One of the rubber lines had burst after parking it in the garage overnight. FYI they are formed lines that are specific to the car and you can't just replace them with regular line from autozone. Maybe one of them is crimped or collapsed... Check for that as well. Coming from the hard line from the tank to the fuel pump.

H8ntrnks

Fuel was my first thought too. Just very strange how it was giving charging issue symptoms. Stalled, then try and fire it up and chug chug click click click. Like a dead battery. Couldnt start it until we jumped it. Then fired right up. Like I said though, battery and alternator tested fine. It was getting quite late, so ill be checking fuel pump,lines, filter over the next few days when i have the time. Thanks for the replies so far. much apprciated.

jlpskydive

could be a a bad solenoid also, just a thought... That is the weak link in almost every car.

ntfday

If you find the time pull your starter and thoroughly check it out. Make sure the brushes are in good shape and take a fine piece of emery cloth to the commutator. If anything I'd replace the solenoid as IMHO they are the weak link in a GM starter circuit.
If the car sat for any period of time the fuel in the car went south and you will probably end up dropping the tank for cleaning and blowing out the fuel lines.

H8ntrnks

As far as I know the car has been a driver. Hasnt sat long enough for fuel to go south. My initial thought was the gas gauge was off and I was out of gas. Embarrassing. But if i was out of gas then why would it only stay running if I was on the gas? The second I let off the gas it would die. Put about 2 gallons in it anyway which got it up above a quarter tank, which is where it was last when it was running fine before the trip to attempt to get gas. After tinkering around checking the charging system out. I put it on a trickle charger for a while. Tried starting it and fired right up and ran fine. Let it run for probably 5 minutes and never stalled. Even more confused.

ntfday

The starter is in the middle of the charging system and a faulty one can cause problems such as yours along with bad fuel. As I said earlier I would pull the starter and go through it.

sparky77

When the engine is running are you getting 14 volts to the battery and when you shut down the engine do you have at least 12 volts at the battery?

Rodnok1

You probably have a couple issues, one fuel level was too low(or weak pump) and a case of hot start. Startes and wiring next to exhaust is a wonderful idea... I usually upgrade the wiring/replace to any sbc and use a quality starter.
Couldn't hurt to check/clean all the connections as any corrosion will give you issues also.

pigfarmer

Sorry if you already know this but curious how you tested the battery. A voltmeter alone won't always help. Load test it - I got burned once on a new motorcycle battery. Since it did fire up & run I'd assume you have spark but that's easy enough to check.

Very low fuel level made me wonder. I'd use a can and add maybe 5 gallons of fresh high octane gas with some Seafoam in it. Good stuff. Can't hurt.

If you have an inline fuel filter they are cheap enough to replace. Some carbs also have a porous stone filter right at the fuel inlet. I have a Holley 4160 and there are sight plugs on the primary & secondary I can remove and see if the bowls are filling. Stuff some rags underneath if you do that.

Weak batteries and gunk in the fuel lines are common in hobby cars. Good luck - hope it works out OK for you.

Easy Mike

Is there fuel in the tank? You said it was on E and you were intending to go to the gas station. What is the idle speed with the car in gear? What is the condition of the battery and cable ends?

Rky Mtn C6

H8ntrnks

Thanks for the replies everyone. Going to have the battery load tested and the alternator bench tested. All I had was a meter at the house. Gonna run a charging system test tonight to rule that out. Then it will be on to looking through the fuel system and double checking spark again. Only have a short time each night to work on it. Ill spend more time this weekend. As of right now, the car fires up and runs fine. Doesnt stall out. So its a bit of a head scratcher at the moment. Dont want to take it for a ride until I can try and find out the issue that happened yesterday. Really dont feel like getting stranded and towed again. We'll see what happens.

LS4 PILOT

this sounds like fuel issue , something is clogged , trash in the gas tank , fuel filter , .....or you could have more than one problem ..... your battery has a slow discharge leak somewhere in a lamp , radio ,saftey switch , and the car was not run enough to keep up,with the minute battery drain .....keep it charged, these old cars don't have the capacity to charge as fast as new ones today. Your battery sounds like it was discharging while it sat. If there is tiny issue of ground then the battery will,drain pretty fast. Corvettes are fraught with these issues. I had a key switch in my 74 camaro that was worn and would release the key in other postions where it was suppose to,prevent the key from coming out of the cylinder . If there is no battery drains , the car should sit for weeks and a good battery will have pretty of power to start it.

Ole Red 77

You may just have a bad battery. Mine did what you're describing a couple of years ago. Took it to Autozone and they tested the charging system. Battery was bad, and it was only a year old. Replaced the battery and it's run fine since.