AyWoSch Motors
The Parts Guy
- Joined
- Nov 6, 2020
- Posts
- 4,684
- Reaction score
- 13,635
- Location
- New Mexico
- First Name
- Ayden
- Truck Year
- 1986
- Truck Model
- K1500 Sierra
- Engine Size
- 350ci V8
I have a 1973 Towanda 454 in my 75 blazer.
It's got open long tube headers, and a Carter AFB 950cfm racing carb, but otherwise stock 454. I also have a manual choke.
It's always run pretty well, with its fare share of hiccups, but last year before winter came, I covered it up and put in hibernation for a while.
So yesterday, I unwrapped it and cleaned it up, and ran it for a while to get the juices flowing.
It started okay, and idled fine at first, but then it started idling rough and died. It started up again, and I nursed it a bit, then it ran okay again. After letting it warm up for 10 or so minutes, I took it out for a few laps. After a few laps it was running better, but still not like it used to or should. I took it out around the property for some off roading, and after putting around for a while it started running worse and worse, then it wouldn't run in 1st gear, so I threw it in low, and babied it back home. It would only stay running at higher revs, would not idle.
So its symptoms are running rough, doesnt idle well right now unless with a little throttle input. It doesnt sound smooth like a V8 should. It's running on all 8 I believe, but not nicely. Its back firing alot, popping bits of flame out the exhaust. When revving it higher, it's a bit shakey.
I cant hear anything obviously wrong with it, but its super loud, so you cant hear much anyway. It runs about 60lbs of oil pressure, runs very cool.
It oil is oddly black/dark gray, but no metal whatsoever. It should be clear and golden brown like it, because I just changed the oil recently, but it isn't. And my sense of smell isnt great, but it seems to smell a bit like gas. It's also a bit thin feeling. Dont know if thats from gas, or if it's from water.
When I first got it, the oil was black as soot, and smelled like gas really bad, so I changed it, so maybe it's going back to it's old habits.
Last summer the hood blew off during a rain storm, and the engine got filled with water. I pulled the plugs, cycled it to get the water out, cleaned the plugs, changed the oil. It ran fine after that, like always. Oil did go a little gray and creamy from leftover water, so I changed it again. Once again, ran fine after that.
I suspect it might be the carburetor. I'm not good at tuning them, I just got it from my boss who said it ran well, and I threw it on ther and ran it.
And is 950 just too much carb for that engine? Might be why it backfires and makes the oil smell.
I have a nice Rochester Quadrajet that's really well tuned, super snappy throttle. The 350 it's on right now , purrs like a kitten, should I swap that on there, and see if that helps?
I really want this to run well again, and I really dont want to hurt it. Please help.
It's got open long tube headers, and a Carter AFB 950cfm racing carb, but otherwise stock 454. I also have a manual choke.
It's always run pretty well, with its fare share of hiccups, but last year before winter came, I covered it up and put in hibernation for a while.
So yesterday, I unwrapped it and cleaned it up, and ran it for a while to get the juices flowing.
It started okay, and idled fine at first, but then it started idling rough and died. It started up again, and I nursed it a bit, then it ran okay again. After letting it warm up for 10 or so minutes, I took it out for a few laps. After a few laps it was running better, but still not like it used to or should. I took it out around the property for some off roading, and after putting around for a while it started running worse and worse, then it wouldn't run in 1st gear, so I threw it in low, and babied it back home. It would only stay running at higher revs, would not idle.
So its symptoms are running rough, doesnt idle well right now unless with a little throttle input. It doesnt sound smooth like a V8 should. It's running on all 8 I believe, but not nicely. Its back firing alot, popping bits of flame out the exhaust. When revving it higher, it's a bit shakey.
I cant hear anything obviously wrong with it, but its super loud, so you cant hear much anyway. It runs about 60lbs of oil pressure, runs very cool.
It oil is oddly black/dark gray, but no metal whatsoever. It should be clear and golden brown like it, because I just changed the oil recently, but it isn't. And my sense of smell isnt great, but it seems to smell a bit like gas. It's also a bit thin feeling. Dont know if thats from gas, or if it's from water.
When I first got it, the oil was black as soot, and smelled like gas really bad, so I changed it, so maybe it's going back to it's old habits.
Last summer the hood blew off during a rain storm, and the engine got filled with water. I pulled the plugs, cycled it to get the water out, cleaned the plugs, changed the oil. It ran fine after that, like always. Oil did go a little gray and creamy from leftover water, so I changed it again. Once again, ran fine after that.
I suspect it might be the carburetor. I'm not good at tuning them, I just got it from my boss who said it ran well, and I threw it on ther and ran it.
And is 950 just too much carb for that engine? Might be why it backfires and makes the oil smell.
I have a nice Rochester Quadrajet that's really well tuned, super snappy throttle. The 350 it's on right now , purrs like a kitten, should I swap that on there, and see if that helps?
I really want this to run well again, and I really dont want to hurt it. Please help.
