Choke

Topic: Choke (Read 850 times) previous topic - next topic

Choke

July 20, 2006, 12:01:10 PM

This weekend I'm installing some Mk 7 headers I got. Assuming I get them on, there's still the issue of my carburetor's hybrid exhaust/electric heated choke (why would someone design such a thing?). The choke takes exhaust flow from the stock manifolds, now I could just drill a hole in my headers to accept that line but why would I want to do that?

The choke is also heated from the alternator stator wire. I guess I'm asking opinions. Do I hunt through the junk yard to get a full electric version (I've seen them) or can I somehow use my current choke? It's less than a year old, I'd rather it than some old piece of junk.

Choke

Reply #1 – July 20, 2006, 12:03:21 PM

First off I have no cule but Nice bird

Choke

Reply #2 – July 20, 2006, 03:51:54 PM

Thanks man. I had a look at your cardomain page, that's pretty harsh what's been done to the wiring. Are you still on it? My car was never fuel injected so I only have so much advice to contribute. I do know you can eliminate atleast some of the wiring and controllers if you install a HEI distributor and a 3G alternator as I've done. I'll have another look at the pics when I get home from work.

Choke

Reply #3 – July 20, 2006, 04:29:30 PM

How it works from the '84 shop manual:

"The hot air choke with electric assist choke cap functions as follows: as the engine warms up, manifold heat transmitted by hot air to the choke housing relaxes the bimetal, permitting the choke to open. This is accomplished by the thermactor air pump which forces clean air through the exhaust manifold heat stove where the air picks up heat and then through the choke housing assembly where it heats up the choke system and exits through choke exit.
The electric assist has a ceramic heating pill. At temperatures above 12*C (54*F) to 23*C (74*F) the temperature sensing switch closes and current is supplied to the heater causing the bimetal to pull the choke plate open at an increased rate."

"The all electric choke has two heating pills. One pill is energized all the time after the engine start up; the other functions similar to the electric assist choke."

Both types were used on the Model 2150 carb.

Choke

Reply #4 – July 20, 2006, 05:43:38 PM

Well I guess that explains why I can't keep using the same choke. Least not for long. Although mine was never connected to the thermactor system, it was connected directly to the exhaust manifold. I'll have to score an electric choke.

Choke

Reply #5 – July 20, 2006, 06:00:33 PM

I think it is hooked to a tube inside the exhaust manifold or a chamber that is seperate from the exhaust (Heat oven). The other end of the tube or chamber goes to smog pump air.

Choke

Reply #6 – July 20, 2006, 06:12:26 PM

You did say carb? If so you could get a electric choke to replace it it has its own temp spring only "-and+ to hook up."

Choke

Reply #7 – July 20, 2006, 06:15:50 PM

There should be a tube inside the exhaust manifold that the choke should be connected to. One tube going to the exhaust manifold should come from the clean air inlet tube on the carb, and the other should go to the choke. There is a way to keep your current choke, but it might require changing the intake, thenits just easier to change to a full electric choke. From the pics you can see the similar set up, it just installs into exhaust port of the intake manifold instead of the exhaust manifold itself. The part number is D0AE-9A705C. Hope this helps.