engine and drivetrain 38/38 choke

[landon]

Just installed maunal choke conversion and it has solved the problem of having the choke on or off when I want it. Another problem persists though. The engine fires immediately and idles at the fast idle speed of 1600-1800 rpm. After 10-20 seconds it slowly dies. I have to blip the throttle periodically to keep it runnung. After a couple of minutes (when temperature is in the blue zone) it will idle steady. Any ideas?

[742002]

i have the electric choke on my 38/38. it is somewhat a pain in the ass, although i don't think it is working properly. the car starts fine, but i have to hold the revs myself with the throttle until it is just out of the blue zone.

[Guest Anonymous]

My car is exactly the same. How does one go about installing a manual choke?

[landon]

Pierce manifolds has a kit for about $45.00. Easy to install, it simply replaces the old coil with a cable operated gear to operate the choke.

[BarryA]

choke activated but the idle speed drops off and the engine dies a few seconds later with the knob still pulled out, it sounds like maybe something's not right in the carb linkage.

If everything's hooked up properly, the fast idle cam on the carb linkage should hold the engine at a high idle until the choke is deactivated (regardless of whether it's a manual, electric or water heated choke).

Virtually all choke mechanisms work essentially the same way - when the choke is activated (by pulling on the cable knob, or by an "automatic" heated coil) the carb linkage effectively repositions the idle stop (forcing the engine idle faster once it starts), and a spring loaded link closes the choke butterfly to restrict airflow while the engine starts.

Once the engine is running, airflow through the carb's air horn works against the spring-loaded choke linkage and pulls the choke butterfly part-way open (allowing enough air through for the engine to run but still restricing airflow, thus enrichening the air-fuel mixture), but the idle speed stays up until the choke is deactivated (either by pushing the choke cable knob in, or by the electric or water heated coil expanding) and the idle stop returns to the normal running position.

The theoretical advantage in an "automatic" choke is that the choke should gradually open at a rate matched to the speed the engine warms up so the engine runs only as rich as necessary to keep it running smoothly until it reaches operating temp - in my past experience that rarely happens, especially with aftermarket carb/intake manifold combos.

[landon]

Yea..I'm stumped because when the choke cable is pulled, choke plates close and throttle plates open against the fast idle cam. Adjustment of the fast idle screw produces good fine adjustments of idle speed. At start up it goes right to the high idle speed. After some warm up it will idle strong. It is only during the first couple of minutes that it wants to die but a small tap on the gas pedal will return it momentarily to the fast idle speed. Maybe i'll pull the carb to take a closer look at the linkage

[Guest Anonymous]

I would suggest that you have not adjusted the linkage correctly, you say choke operates and the choke flap fully closes, in that case you are pulling the choke all the way out? if so and the engine starts to die after a while then you are overchoking the engine, try as soon as it starts to slowly push the choke in. It may help.

[mikem]

I have found that the manual choke kit I installed on my Weber 38DGES does not operate as well as the factory manual 32/36 DGV that I have. It gets the job done, but just not as intuitively.

I took the aircleaner off and observed the operation of the choke relative to the pull-knob and gas pedal in order to get a better feel for it's operation.

BTW, the manual conversion kit is also for the 32/36DGAV carbs.