Rough running Olds 350

[bluesman79]

Hey fellas AND ladies, I have an '81 Cutlass with an '72 Olds 350 that is running weird now. About 3 weeks ago I replaced the spark plugs because it was running rough all of a sudden. It ran fine for a few weeks. A couple days ago I adjusted the carb (i'm a noob) and now it's beginning to run like crap. Before all of this, my dad said I needed to get the timing adjusted because it was backfiring through the carb, haven't done that yet. But here's the thing, it runs perfect when it's just warming up, but after 15-20mins of driving it takes a nose dive and starts running like pure crap, like it's got bad spark plugs (it sputters and runs rough). I've searched the boards and read that it could be the ignition module and i'll probably get that checked along with the ignition wires. However, it was running rough when it was in the 90s (but now it's dropped down to the low 80s and it still runs rough after a few miles of driving. The temperature gauge is steady at 190 degrees, but jumps up if it sits in stop and go traffic for too long. I hope i'm not leaving anything out to get a better understanding of the problem, but what do you guys think? I drive my car EVERYDAY to work, it's my only car. HELP, lol 🙁

 

[bill]

Sounds like a carb issue. And, I would find out why its running hot. Olds motors like to run a bit warmer than most, but over 220 is too much. Back firing through the carb usually is a carb or timing issue. Have the carb rebuilt first, then set the timing at idle w/the engine warm and the vacuum advance hose plugged. Good Luck!

 

[bluesman79]

Sounds like a carb issue. And, I would find out why its running hot. Olds motors like to run a bit warmer than most, but over 220 is too much. Back firing through the carb usually is a carb or timing issue. Have the carb rebuilt first, then set the timing at idle w/the engine warm and the vacuum advance hose plugged. Good Luck!

Yeah, the timing is so off that it actually caught on fire one day. If it sits for more than 20 mins without running, the engine overheats. If it sits idling for too long it overheats, it's crazy. Once it's going down the road, the temp gauge goes down to regular operating temp. It was hard to crank one day while it was hot and I pushed the gas pedal to the floor, next thing I know the engine starts smoking. I pop the hood and a big *ss flame is coming out of the carburetor. Burnt my air filter to a crisp, it looked like I was bbqing on the damn thing, lol. I ran back into the restaurant I was at and had the cook dump some water on it. IT WAS BAD. I let the car sit for 1hr 30mins and it started right up. I've got so many problems with this thing it's ridiculous, sigh...At least it's not smoking... anymore :? I'm not giving up on this thing, I just bought it in March of this year. I'm definitely putting a 455 in it early next year, believe that buddy!!! Just want my current engine to purr and roar like it should ya know...

 

[84dragcutlass]

Definatly need to get that timing in before you try and tune it more or say its a bad carb. Bad timing can lead to hard starting, overheating, and engine damage. Plus if its to far off it can fire at the wrong time in the cycle and spit flame up through your carb which could be causing your home made bbq. Hook a light up to it, quick and easy