1967 Pontiac Grand Prix 400 CI engine, 350 horses. Timing set correctly, carb air/fuel mix screws set with a vacuum gauge and by RPM's indicator. . Electric choke--Electronic ignition . Carb. overhauled. Runs beautiful when warm but rough when cold. Any suggestions? Vacuum and compression checks out o.k. Lou
2007-01-15 14:25:24 · 8 answers · asked by Navylou 1 in Cars & Transportation ➔ Maintenance & Repairs
Sounds like the choke pull-off has a leak. It should pull the choke open slightly when the engine starts cold. As it warms up, the choke thermostat will gradually open the choke fully. To see if the pull-off is the problem, start the engine cold. Let it run for a bit until it screws up and starts smoking and then open the choke with your finger. If the smoke clears up and the engine smooths out (it may stall shortly after that due to the choke being too far open), that was it. The choke not opening enough is about the only thing that could could cause this problem only when it's cold.
2007-01-15 14:30:37 · answer #1 · answered by Anonymous · 2⤊ 0⤋
Sounds like the choke needs to be adjusted.
There should be three screws you can loosen. On the side.
Do this when it is cold. Loosen the screws and the whole black plastic part can rotate to adjust the choke. Adjust it to where the gap between the choke butterfly and the bore is about 1/4" You need to floor the throttle once before you do this.
2007-01-15 18:11:58 · answer #2 · answered by adventurouscouchpotatofun 2 · 1⤊ 0⤋
Black smoke at start up means: TOO RICH, TOO much fuel.
Blue smoke out the exhaust means: Burning OIL or OIL leak into the combustion chamber.
White smoke out the exhaust means: Coolant or water leaking into the combustion chamber. It doesn't burn, but just boils away.
Most likely problem is a non-functioning or incorrectly adjusted electric choke. The heated choke on this carbureted car should open slowly just by turning the key to "ON" position without starting the engine.
2007-01-15 14:49:00 · answer #3 · answered by Phillip S 6 · 0⤊ 0⤋
next time when you start it up,and when it starts to run rough,take off the air cleaner and open the choke up by hand(just the butterfly)and see if it runs smoother.it sounds to me like the choke isnt opening up enough,also check the choke pull off,it might need adjusted to make it open up more when its cold.
2007-01-15 17:43:20 · answer #4 · answered by Anonymous · 1⤊ 0⤋
I have not got any concept yet i'm getting chilly interior the iciness and warm interior the summertime. bypass parent. My husband is Asian/White and he's a Florida community and he's able to tolerate warmth better than i'm. interior the iciness, we are the two chilly as hell. I have not got any concept. To be straightforward on the subject of the stereotypes that whites positioned on turn-flops interior the iciness, I even have seen many black chicks donning open-toe footwear in lifeless iciness with snow on the floor to the club lol.
2016-10-31 05:34:41 · answer #5 · answered by ? 4 · 0⤊ 0⤋
Could it be that the air cleaner is so damp that it is chocking causing a rich condition?If you are running larger than a 750cfm Carburetor you will have this problem.
2007-01-15 14:37:33 · answer #6 · answered by (A) 7 · 0⤊ 0⤋
Fuel mixture is rich at idle, check to make sure your choke is working properly.
2007-01-15 14:32:03 · answer #7 · answered by Anonymous · 2⤊ 0⤋
lou could be weak coil causing weak spark at startupthen as vehicle warms up heats up wire inside of coil and produces good spark// recommend accell high output coil
2007-01-15 14:32:18 · answer #8 · answered by toadyboy 4 · 0⤊ 2⤋