You are correct in that the engine compartment itself generally doesn't make enough heat, fast enough to open a fully closed choke. Some of us have adapted our cars to require less heat (necessarily due to failing choke pull off mechanisms), but that is not the ideal. Running the heater hose up against the housing can help, but with our '50s and '60s cars, only when the heater is on. The choke must be fully closed when the car is cold in order to start easily. The speed of the opening is dependent on the type of car, and the climate. My 1980 FMC Linc. T.C. feeds to power to the choke spring through the oil pressure sending unit! I guess they thought it would match up to the required amount of current needed to open the choke properly. When the oil pressure sending unit failed, I had a heck of time figuring out what was going on with my choke, not that I planned to drive the car with no oil pressure. The trouble was, once I realized that the car had o.p., I still couldn't run it because the choke wouldn't op
en until I replaced the sending unit. This was only true on this model car that came with the H.O. engine option.
That part isn't Imperial related, but since you brought up the question of a power source for your choke heater, it is interesting so I thought I would mention it.
Paul W.
-----Original Message-----
From: Daniel Richardson <TheRichardsonFamily@xxxxxxxxxxx>
To: Imperial Club <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Sun, 14 May 2006 15:50:01 -0500
Subject: Fw: IML: more carb questions
Paul & Brian & others:
I think that it is an electric-thermal choke set up. The local Carquest guy said I should run the terminals to an ignition switched power source. The 12V helps heat the thermal spring to open the choke as the engine warms up?
Maybe that makes sense - there probably isn't enough heat next to the carb to back the choke off as the car heats up? (otherwise, why have the thermal spring in the intake manifold?) Inside the disk is a piston connected to a vacuum source on the carb, that pulls on the choke as well - that would work like the diaphragm choke pull-off.
The 1967 FSM does identify the 4327 as an HP 440 Auto Trans. carb. But, it makes no mention of any other choke set up for Chrysler except the "well type". In the kit, it shows applications to some GM engines as well - perhaps this carb came off a GM, or maybe the Dodges or Plymouths had this set up, or maybe this is a late '67 year-end issue?
Regardless, now the question is where exactly do the terminals connect to? If anyone could advise, that gets me a little closer.
Regarding the springs, I only noticed the springs on the throttle linkage in the FSM. It seems that the carb itself needs a spring somewhere - maybe not but, I can't figure out how everything operates as it sits now.
Thanks for the help,
Dan Richardson
300L w/ the heart of a '67 Imperial
----- Original Message -----
Sent: Sunday, May 14, 2006 10:29 AM
Subject: Re: IML: more carb questions
I am no carb expert, but the terminals that you describe sound like connections for an electric-thermal choke pull off. I have this on several of my other cars from GM and FMC. There is a disc in the housing that heats the choke spring, activating choke opening during warm up. Imperials from the '60s usually had a spring mounted in the intake manifold that heated up and pulled a lever to open the choke. You should be able to make this work.
Paul W.
-----Original Message-----
From: Daniel Richardson <TheRichardsonFamily@xxxxxxxxxxx>
To: Imperial Club <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Sun, 14 May 2006 09:33:43 -0500
Subject: IML: more carb questions
Hi everyone!
I'm rebuilding a Carter 4327 to go on the '67 Imperial 440 I have in my 300L. Any carb experts out there?
In the FSM, it identifies that carb application as a non-CAP, High Performance. A-OK with me. The carb has a choke set-up that is not shown in the FSM - at least I don't think so. (the FSM refers only to a "well type" choke - that's the kind that hides in the intake manifold, right?) This choke is a disc, just a bit smaller than a snuff tin, mounted on the carb right where the vacuum choke pull off would be. It has the thermo-coil in the housing and also a piston that seems to act as the vacuum choke pull-off.
The rebuild kit shows this choke set-up on the diagram - still A-OK. One question is - what are the two electrical terminals on the outside of this choke housing, disc looking thing for? Do they need to be connected to anything for the choke to operate correctly? Or, are they test leads for the mechanic to check choke operation?
Also, I am missing the choke connector rod (I might find one in the basement) and I am not sure where it attaches. To the slotted bracket or to the hole on the choke rod?
Lastly, I have no springs pulling on any of the carb linkage (except throttle rod and throttle return). In trying to figure out the operation of the primaries & secondaries, it seems that there should be something pulling on something else.
Wow! Way too detailed - and yet way too vague!! Is there a Carter doctor in the house? Or anyone that has a rebuild book that can advise of the way chokes and springs work?
I know this is a tough one!!! Thanks,
Dan Richardson
300L with the heart of a '67 Imperial inside
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