I have a 79 Camaro and I’ve gotten a new carb(2 bbl dueljet Rochester) and distributor on it. I got timing right I do believe. I have been having problems trying to get it to start. The car just cranks real fast( sounds like good timing) , but it did sputter out the tail pipe and it shoot out dark grey smoke the first couple times then stopped. I had someone try to start the car while I was near the front to listen and I heard an exhaust leak near the manifold. We fixed that but it still isn’t starting. Now it just keeps turning over real fast and that’s it. I looked in carb and it’s getting gas, and it’s getting spark. I tried to mess with the carb a little to let it get more air in it. Didn’t help, would I maybe have to open the carb a little more to get more air? I would really like to get some help with ideas on how to get my car up and running again.
If the engine turns over real fast it may mean the timing chain has jumped time.
Mark on the distrbutor body where the number one spark plug tower is located on the distributor cap. Remove the distributor cap and bring cylinder number one to top-dead center. The rotor in the distributor should point very close to the mark that was made on the distributor body. If it points nowhere near the mark on the distributor body the timing chain has jumped time.
I had a 350 chevy engine with 400k miles on it and never had a problem with a chain, chains never go bad. It sounds like a junk chinese distributor. Put a quadrajet on that and a new distributor and make sure its timed right. I was working on my friends transam and had a 12 pack in me and got the distributor in wrong and the car didnt run right.
Follow Tester’s advice above. Timing chains don’t last forever.
If the carb isn’t letting air into the engine, it would make it easy to crank, and you’d get a fast crank. Maybe some obstruction? Or just the carb is no good. Maybe do a compression test too.
You might run a compression check.
A good way to see of the chain is even intact is to crank the engine with the distributer cap off. If the rotor doesn’t spin, your timing chain is broken entirely. It sounds to me like the engine isn’t pumping any air at all, and is why I suspect the chain. if it IS spinning, then take Tester’s advice.
I have replaced a great many jumped timing chains on small block Chevrolet V-8s and 4.3L V-6s.
I have seen many a small block chevys that had 500k on them on the original chain. Chains are metal and they dont stretch, the teeth may wear some but I have found an engine runs a little bit better when its a bit loose.
Maybe the weather down here affects the chains, @Rick. I won’t venture to guess how many I have changed though. More than I could count even if I took off my shoes for sure.
This vintage of GM vehicle has the cam gear teeth made of plastic. So it’s not the timing chain that fails, but instead the plastic teeth on the cam gear.
One way to find this out is, drain the oil. And if small bits of plastic are found in the drained oil, the cam gear let loose.
They do indeed stretch Rick. I’ll firmly disagree with you there. I’ve seen some chains that were so loose, they actually wore a hole into the timing cover.
And I’ve seen timing chains so loose they were removed without removing the timing gears! And the vehicle still ran! Although not all that well.
“This vintage of GM vehicle has the cam gear teeth made of plastic”. My parents had the same problem as the OP with a 1969 Pontiac LeMans with the 350 V-8 engine. I never understood why the plastic gear was used. As I remember, the replacement gear was metal. The story from GM was that the plastic gear ran more quietly, but I don’t remember the metal timing gear as being noisy. Also, I think my dad’s 1939 Chevrolet had timing gears made of some kind of fiber, and a stripped timing gear was not unusual in these old “stove bolt” 6 cylinder engines.
I also have to disagree with you
Timing chains can most definitely stretch
Where are you getting your information, by the way?
Nice thing about those old Chevy engines; it isn’t very difficult to check some things out. Remove the distributor cap, set the timing at TDC and look at the rotor position. If it isn’t pointing at the #1 or #6 spark plug wire terminal, you can bet that you need a timing chain and sprockets. Before you do that, make sure the rotor isn’t damaged or the center electrode in the cap isn’t missing.
Compression of 20 to 40 PSI will tell you that the timing chain should be looked at. You might even get 80 PSI.
As always, check the gas gauge. Other possibilities are ignition module, fuel pump pushrod bent, fuel pump bad (easy to check) and ignition coil bad.
I had a Rochester Carb in my old Nova and it always gave me trouble starting- I had my mechanic replace it with a Holley Carb and that fixed the problem.
The turning over real fast, indicates to me that you have little to zero compression. That means the values are out of time, if they are moving at all. Was this motor running with the old distributor and the old carb? I think you have more diagnostics to do. A compression check is a good starting point.
is the dist. installed on the money or a tooth off and chains don’t last for ever
Has Berlinetta left the building?