1980 Buick Century Not Working (3.8 2 barrel N/A) HELP!!

[gbodybuick]

Make a mark or label before removing or loosening anything..

Your comment "runs normal until you try to drive it" belongs in the G-Body Hall of Fame!

It is right up there with "how did it run before you painted it?"
and "did you try to drive it without turning?"

View attachment 231875

It does indeed! Good diagram. Another note is when you start it, it will struggle until it finally starts, it will sound like a freaking lawn mower at first, almost like only half the engine is firing, and then it will eventfully run normal. Idles fine but sounds really weak and sometimes hesitates when you rev it.

 

[78Delta88]

By all your symptoms and your car being older than my daughter. Common problem with Buick, Chevy and Pontiac, your nylon coated timing gear (cam) shredded the nylon and your timing chain jumped.

Accounts for poor idle hard starting and will run at very high RPM until you put a load on it and it dies.

There are a few other things to check first, because the engine is a system... Air... Fuel... Fire and then all contained in a mechanical device regulated by crank position, valves, valve position, compression and gaskets that supposedly keep things where they should be.

First things when keeping these old beasts. Get good with; vacuum gauge, fuel pressure guage, volt and amp meter (VOM) and timing light.

**Not knowing how is just the reason needed to learn it. Or throw money at mechanics that are absolutely clueless without a scan tool.

 

[gbodybuick]

By all your symptoms and your car being older than my daughter. Common problem with Buick, Chevy and Pontiac, your nylon coated timing gear (cam) shredded the nylon and your timing chain jumped.

Accounts for poor idle hard starting and will run at very high RPM until you put a load on it and it dies.

There are a few other things to check first, because the engine is a system... Air... Fuel... Fire and then all contained in a mechanical device regulated by crank position, valves, valve position, compression and gaskets that supposedly keep things where they should be.

First things when keeping these old beasts. Get good with; vacuum gauge, fuel pressure guage, volt and amp meter (VOM) and timing light.

**Not knowing how is just the reason needed to learn it. Or throw money at mechanics that are absolutely clueless without a scan tool.

I think we have ruled out the possibility of a worn nylon tensioner and subsequent skipped timing chain tooth. Logic as follows:

A friend came over with an inductive timing light with advance capabilities. We marked the groove on the fly wheel with white paint, started the car, (with great difficulty!) and checked the stroboscopic timing with the inductive sensor on spark plug wire number one.

At idle, the flywheel mark was within the range of the toothed timing demarcations, some few degrees before top dead center.

We advanced the strobe so that the mark was in plain sight and revved the engine. Sure enough the timing mark on the fly wheel moved in the advancing direction with RPMs, indicating to us that the car’s vacuum advance mechanism is functioning properly.

Are we missing something or can we assume with these observations, that everything to do with vehicle ignition timing is in order?

If so, any other ideas as to what is causing the following:

Great difficulty in starting the engine with a propensity to easily flood. Once started, the engine races smoothly, and normally, and upon warm-up and tapping the throttle, goes to a nice, smooth idle.

Putting the car in drive, and stepping on the throttle, causes the engine to sputter and stall every time.

 

[78Delta88]

That's good news. So if "Fire" is ok then look at the others.. Remember. Air....fuel....fire is the mantra. Of course also based on good compression, good head gaskets, etc...

Sputtering under acceleration also possible points to coil getting or being weak.

Also points to fuel insufficiency. These are just possibilities. But as items get ruled out you get closer to true root cause and the item to fix.

 

[Sweet_Johnny]

Are you 100% sure it's flooding or is it just not trying to fire?

Just for fun, drop your gas tank and check the hoses on top of it. I saw the ones in front of the tank looked good on my Cutlass when I had similar issues and I blamed the carb, distributor, and vacuum leaks. It was this:

My car had trouble starting and required starting fluid to get going. It would die if left to idle, especially in gear. It would only run between about 1500-3000 rpm- too low or too high and it starved to death. The problems initially presented as potential carb and ignition issues.

 

[spongbob]

Yes take your spark plug out and see what color they or it are ? Is the plug insulator black have a fluffy black or look like it's painted black .if so you can try changing plugs....or sandblasting old plugs....if you find this condition. Your likly glass glazing your spark plugs from a leaky float valve ( dirt on float valve ect ).check the inside of the distributor cap for cracks or carbon tracks....regardless of timing light ,take the distributor cap off and turn the engine with a breaker bar or by hand first turn it in one direction about an inch ( of the main pully on end of crankshaft) then turn it back the opposite direction .do this several times while you stare at ( watch) the rotor button if your rotor changes directions with the crankshaft before it moves say 25 degrees ( (about an inch of crank rotation) in opposite direction,then dismisse the timing chain concerns but it it takes Over and inch of crankshaft turning as far as when changing direction you should seriously consider removing the timing cover to address the excess timing chain play....check the carb secondary throttle plates ( butterfly) to see it is not sticking open (ignor this on 2 barrel)slightly.maybe oil the shafts check the distributor centrifugal advance weights put a spot of oil on them and there pins [Ignor this if distributor has no weights]..if possible get the car up to warm temperature and then turn off the motor and pull some spark plugs are any fouled ( black or black oily ?) If so change them if they have too much oil on the insulators ( nose of plug) and your valve covers are leaking oil when you change them plugs put a small smidgen of grey silicone on the last sealing threads to prevent oil from leaking in on the threads and accumulating. If there is not spark plug fowling ? you could try wireing the chock to half on and see if your car still stalls( temporary test with steel wire) in gear...if this helps check to see if the brake vacuum booster has a vacuume leak ( cracked diaphraim) and the fuel filter ( stoped up ?) and gas tanke hose route for cracks or pinholes .check the oil for gasoline in it also check any filter in the front of carb if you haven't? If you decide too check the main jets in the old carburetor could have one blocked by debrie ,rust ect...good luck

 

[gbodybuick]

Yes take your spark plug out and see what color they or it are ? Is the plug insulator black have a fluffy black or look like it's painted black .if so you can try changing plugs....or sandblasting old plugs....if you find this condition. Your likly glass glazing your spark plugs from a leaky float valve ( dirt on float valve ect ).check the inside of the distributor cap for cracks or carbon tracks....regardless of timing light ,take the distributor cap off and turn the engine with a breaker bar or by hand first turn it in one direction about an inch ( of the main pully on end of crankshaft) then turn it back the opposite direction .do this several times while you stare at ( watch) the rotor button if your rotor changes directions with the crankshaft before it moves say 25 degrees ( (about an inch of crank rotation) in opposite direction,then dismisse the timing chain concerns but it it takes Over and inch of crankshaft turning as far as when changing direction you should seriously consider removing the timing cover to address the excess timing chain play....check the carb secondary throttle plates ( butterfly) to see it is not sticking open (ignor this on 2 barrel)slightly.maybe oil the shafts check the distributor centrifugal advance weights put a spot of oil on them and there pins [Ignor this if distributor has no weights]..if possible get the car up to warm temperature and then turn off the motor and pull some spark plugs are any fouled ( black or black oily ?) If so change them if they have too much oil on the insulators ( nose of plug) and your valve covers are leaking oil when you change them plugs put a small smidgen of grey silicone on the last sealing threads to prevent oil from leaking in on the threads and accumulating. If there is not spark plug fowling ? you could try wireing the chock to half on and see if your car still stalls( temporary test with steel wire) in gear...if this helps check to see if the brake vacuum booster has a vacuume leak ( cracked diaphraim) and the fuel filter ( stoped up ?) and gas tanke hose route for cracks or pinholes .check the oil for gasoline in it also check any filter in the front of carb if you haven't? If you decide too check the main jets in the old carburetor could have one blocked by debrie ,rust ect...good luck

Alot to take in. I took some of plugs out and they have a black film on them, not much oil though, they spark fine when I bench tested them. I took them to my local mechanic and he said they were fine it just runs a little rich which I think is normal. The carb is essentially brand new and was professionally tuned. I will check the distrubuter again ( I did allready worked fine). I do notice that my brake master cylinder leaks brake fluid as its very rusty even after I had it replaced a year ago. However, it has always been like this and didn't have a problem. Freindly reminder that it was working flawlessly when I drove it to work, I then parked, went in for a quick 5 hour shift, came back out, started it like normal, kicked the gas down, it idled for a few min and then died. When I finally got it running after much trouble the next day and tryed to drive it it would instantly die. I feel like its either the engine or the transmission, not both, it just wouldn't be likely for them to both fail at the exact same moment.

 

[gbodybuick]

Are you 100% sure it's flooding or is it just not trying to fire?

Just for fun, drop your gas tank and check the hoses on top of it. I saw the ones in front of the tank looked good on my Cutlass when I had similar issues and I blamed the carb, distributor, and vacuum leaks. It was this: View attachment 232003 View attachment 232005 View attachment 232004

My car had trouble starting and required starting fluid to get going. It would die if left to idle, especially in gear. It would only run between about 1500-3000 rpm- too low or too high and it starved to death. The problems initially presented as potential carb and ignition issues.

These symptom's sound very similar to mine, however I could hear the gas skirting into the engine car when I pump it and I even tryed pouring a little gas into the engine.

 

[Sweet_Johnny]

These symptom's sound very similar to mine, however I could hear the gas skirting into the engine car when I pump it and I even tryed pouring a little gas into the engine.

Same here. I bottle fed mine, pulled the top half of the carb off, changed things, etc.. Mine had been sitting for some time, I got it going and drove it for 2-3 weeks, then it did exactly what yours is doing. My pump was barely pulling enough to keep the engine alive but the accelerator pump would squirt because the bowl got filled at least once- you'd see and hear it shoot fuel.

Until I pulled the tank I was guessing trying to diagnose the combination of problems: Ignition? Carb? Leaks? I put on 2 different fuel pumps and pulled the filter about a dozen times, in addition to other things. Two feet of bad rubber had made my car un-driveable. It may seem like a big undertaking to drop the tank but in actuality it's a few hose clamps, 2 bolts, and 2 wires for the sending unit. With the car on stands and a jack for the tank it doesn't take one person long if the tank is near empty.

 

[gbodybuick]

Same here. I bottle fed mine, pulled the top half of the carb off, changed things, etc.. Mine had been sitting for some time, I got it going and drove it for 2-3 weeks, then it did exactly what yours is doing. My pump was barely pulling enough to keep the engine alive but the accelerator pump would squirt because the bowl got filled at least once- you'd see and hear it shoot fuel.

Until I pulled the tank I was guessing trying to diagnose the combination of problems: Ignition? Carb? Leaks? I put on 2 different fuel pumps and pulled the filter about a dozen times, in addition to other things. Two feet of bad rubber had made my car un-driveable. It may seem like a big undertaking to drop the tank but in actuality it's a few hose clamps, 2 bolts, and 2 wires for the sending unit. With the car on stands and a jack for the tank it doesn't take one person long if the tank is near empty.

Very interesting, I went out and purchased some starter fluid, held the choke open and sprayed some and it fired right up and was able to idle. I was actully able to drive it up and down my driveway. But its hard to describe, when you reverse, stop, go in drive (or vise versa), your fine applying a normal amount of gas, however, if your in gear or park and your stopped for like 10+ sec it will studder when you give it some gas, but it won't competently die (like it did before). When I shut off the engine for 1-2 min and turn it on it starts fine, but if its 5-10 minutes it wont start unless I spray some more starter fluid in it. Im gonna drain, drop the tank tomorrow, replace those lines and pour 5-10 gallons of fresh gas in it and see what happens. Another note, it still has flooding problems and doesn't want to start unless I hold the choke open (Im hoping this is related to the gas tank lines). This is a great response you had, I would have never thought of the lines from the tank espically with the carb seeming like it pumps gas fine.