Would it be correct for my 67 400 to have an electric or manual choke? I am so unfamiliar with this it is almost embarrassing!! There are two wires on the driver's left side of the Quadrajet that have power to them. Is this the choke? If not, where would the manual choke be located?
The SOP for today's gas is a lot different than for 1967 gas. Every car will act different, so what I am about to suggest may or may not work.
Here's what you should try:
Pump the gas once all the way to the floor then let off the pedal completely. That engages the choke if the carb is working properly. Crank the motor over. It should fire up but it will probably not continue running. Rinse and repeat. The fuel bowl in the carb is probably empty or nearly so after sitting for more than a few hours.
Some will advocate multiple pumps of the pedal, but always go completely to the floor to engage the choke.
Here's what I do:
Switch on the electric fuel pump for about 5 seconds. Switch off the coil. Crank for about 3 rev's then switch on the coil. Catch and hold the RPM at about 1100 for about 10 seconds then let it idle. It usually runs on its own after that. For hot starting I let the starter run up to maximum RPM before engaging the coil.
You should have what is called a divorced choke. It bolts to the stock intake manifold on the passenger side. They work ok, but electric is preferred and there is a carb company that now makes divorced electric choke setups. I'm gonna pick one up. Here are a few pics of the choke on mine.
they can be adjusted with a flat blade screwdriver through the hole in the side of the housing. just puts more or less tension on the bi-metalic spring which the rod is attached to. they do take some trial and error to get set-up, but work ok when they are.
Ok, I got how to set it. But will it choke by itself during a cold start or I have to choke it from the interior (ie press the gas). Also, to set it I am assuming the car needs to be cold. What parameters or guidelines do I need to look for when setting it? Will I see the primaries close?
Ok, I got how to set it. But will it choke by itself during a cold start or I have to choke it from the interior (ie press the gas). Also, to set it I am assuming the car needs to be cold. What parameters or guidelines do I need to look for when setting it? Will I see the primaries close?
Yes, you have to depress the gas pedal all the way at least once(3 times does it for me). The primary air flaps should close, but not super tight and not all the way. 80%-90% is a good starting point. In a previous post, there is a good schematic of the system. In it you'll find the fast idle screw, its buried under the linkage area. You should set that at about 1500 rpms. You only get one shot a day at this so double check everything before you pull the trigger. Once running, after about 1 minute, tap the gas it should come down about 200-300 rpms, around 1100 to 1200 and the idle should stabilize. This is all I can think of now, let me know how it goes!
Had so many problems with chokes over the years, i've removed them from my holleys and q-jets. I dont have to drive'm during the winter. But they sure are easier to start even when it's 40-50 degrees out.
Your float bowls should stay full for weeks, even months. The only way they should go empty is by evaporation. I have a tri-power with no choke and I pump it a couple times and hit the stater and she's ready to fly. I also have a Holley 800 DP with no choke and it can sit for 6 months and all I do is pump it once and hit the starter and its ready to hammer on. Then I have a Q jet with choke and it is the least friendly to start. If it sits a while like 3 weeks or more I need to set the choke by depressing the gas full. This releases the choke from its last position which would be fully open when engine was driven and warmed up. The choke should/will snap closed and then I turn it over for about 4 seconds to get fuel pressure up and fill accellerator pump cavity and bowl if any gas has leaked,which mine does. (If it doesn't leak you can hit the gas to set the choke, and then give it a couple times to prime the intake and it will fire up) Then I pump another 4 or five times and repeat till it starts. Once it starts, the fast idle keeps it running until the temp gets warm while driving, you may have to hit the gas a bit more to release the choke. Its a pretty simple design.. I have also had other Q-jets fire up instantly after hitting the gas once and then hitting the ignition. These carbs didn't leak gas like alot of Q-jets do. Get Cliff Ruggles book to set up your Q-jet to run its optimal potential. It all depends on the carb.
