New Carter 2bbl Carb - Choke issue

[74Slant6Charger]

So the kid dropped a new ($78!) Carb on the wheezy 318, and overall it was a great improvement. The issue we have is that the choke (also new) keeps the engine choked for far too long. When cold, we 'set' the choke as normal by stepping on the pedal, it fires up great - but soon it's choking out the engine - if we disconnect the choke then, it runs great. Seems to not matter if it's plugged in or not.
Once the engine is warm (and especially the intake hot, cuz that's what the choke reads), it opens up and everybody's happy.

Choke pulloff seems to operate when you hit the throttle... what am I missing??

Thanks all!

 

[91r/t]

A lot of the time, the choke channel inside the intake is plugged with carbon and won't let the choke heat up quick enough to pull off. We took the intake off my 70 duster with the Holley 2 bbl and it was plugged solid with exhaust/sooty ****. If this is the case, your choke spring will never heat up properly and "pull off" in an adequate amount of time. Unfortunately you have to yank the intake and soak is really good to loosen that **** up. I let mine sit in parts cleaner for a few days and kept at it with a brush until it all came out.

 

[74Slant6Charger]

A lot of the time, the choke channel inside the intake is plugged with carbon and won't let the choke heat up quick enough to pull off. We took the intake off my 70 duster with the Holley 2 bbl and it was plugged solid with exhaust/sooty ****. If this is the case, your choke spring will never heat up properly and "pull off" in an adequate amount of time. Unfortunately you have to yank the intake and soak is really good to loosen that **** up. I let mine sit in parts cleaner for a few days and kept at it with a brush until it all came out.

Yeah Pops mentioned that… Probably need to do that. Thank you

 

[91r/t]

Yeah Pops mentioned that… Probably need to do that. Thank you

My car was an Arizona car and they had the choke unhooked. I never knew that either but my dad showed me how the choke heats up and how it won't work at all if it doesn't heat up quick with that port in the intake wide open. Clean that out and I bet 95% or more of your problem is solved.

 

[RJRENTON]

So the kid dropped a new ($78!) Carb on the wheezy 318, and overall it was a great improvement. The issue we have is that the choke (also new) keeps the engine choked for far too long. When cold, we 'set' the choke as normal by stepping on the pedal, it fires up great - but soon it's choking out the engine - if we disconnect the choke then, it runs great. Seems to not matter if it's plugged in or not.
Once the engine is warm (and especially the intake hot, cuz that's what the choke reads), it opens up and everybody's happy.

Choke pulloff seems to operate when you hit the throttle... what am I missing??

Thanks all!

View attachment 940417

Looking at the pix, your choke is heated both by the exhaust cross over well AND electrically with a 12 volt element next to the choke coil, controlled by a temperature activated switch (flat white colored device immediately behind the choke coil element), the purpose of this arrangement was to get the choke open sooner to reduce emissions.
Is the choke coil heater energized? Is there 12 volts going to the choke coil heater? Is the choke coil heater's thermostat good....continuity when cold, providing power to the heater element? Was the choke assembly spring set at the correct preload setting (index setting)? Is the choke pull off diaphragm assembly link correctly set? Is the heat riser valve in the exhaust manifold free to close when cold (they usually fail stuck open). These points are additional to the previously mentioned check points. The heated choke coil assembly together with the crossover heating of the choke coil provides a quick relief to the rich startup mixture. Just my opinion of course.
BOB RENTON

 

[493 Mike]

A lot of the time, the choke channel inside the intake is plugged with carbon and won't let the choke heat up quick enough to pull off. We took the intake off my 70 duster with the Holley 2 bbl and it was plugged solid with exhaust/sooty ****. If this is the case, your choke spring will never heat up properly and "pull off" in an adequate amount of time. Unfortunately you have to yank the intake and soak is really good to loosen that **** up. I let mine sit in parts cleaner for a few days and kept at it with a brush until it all came out.

I cleaned out quite a few back in the day. I chipped out the carbon with a small chisel, seemed to form mostly at the port openings, probably because it would cool down in those areas. Always small blocks. It was also a sign of worn valve stem seals.
Mike

 

[493 Mike]

So the kid dropped a new ($78!) Carb on the wheezy 318, and overall it was a great improvement. The issue we have is that the choke (also new) keeps the engine choked for far too long. When cold, we 'set' the choke as normal by stepping on the pedal, it fires up great - but soon it's choking out the engine - if we disconnect the choke then, it runs great. Seems to not matter if it's plugged in or not.
Once the engine is warm (and especially the intake hot, cuz that's what the choke reads), it opens up and everybody's happy.

Choke pulloff seems to operate when you hit the throttle... what am I missing??

Thanks all!

View attachment 940417

Did you actually measure the pull off opening and compare with specs?
Mike

 

[74Slant6Charger]

No I didn't measure the pull off opening - No idea on the specs.

I've no doubt the choke channel is plugged, and no doubt the valve stem seals are toast.

Was wondering about the Temp activated switch thingy... gotta check the voltage there yes, haven't done that. Might very well not be any power to it. The wiring is a bit borked on this car (original slant car with a swapped 318...)

Thanks for all the tips guys - I really appreciate it.

 

[74Slant6Charger]

Looking at the pix, your choke is heated both by the exhaust cross over well AND electrically with a 12 volt element next to the choke coil, controlled by a temperature activated switch (flat white colored device immediately behind the choke coil element), the purpose of this arrangement was to get the choke open sooner to reduce emissions.
Is the choke coil heater energized? Is there 12 volts going to the choke coil heater? Is the choke coil heater's thermostat good....continuity when cold, providing power to the heater element? Was the choke assembly spring set at the correct preload setting (index setting)? Is the choke pull off diaphragm assembly link correctly set? Is the heat riser valve in the exhaust manifold free to close when cold (they usually fail stuck open). These points are additional to the previously mentioned check points. The heated choke coil assembly together with the crossover heating of the choke coil provides a quick relief to the rich startup mixture. Just my opinion of course.
BOB RENTON

Choke coil heater is energized! I buffed the connections, and I don't know.... but it might be working?! I fired it up cold, and in a matter of a minute or 2 it was fully open. Good news! I am still gonna pull the intake cuz that opening looks pretty scummy. We'll paint it up then too as long as we're in the neighborhood.

 

[RJRENTON]

Regarding the choke pull off setting dimension.....try this: with the pull-off diaphragm under vacuum and the plunger spring extended, hold choke blade closed with a 3/8" or 7/16" drill bit between thr choke blade and
the airhorn wall adjust the U-shape link (open or close) on the pulloff connector for a slight drag....this will be close to the correct pull off opening.
Remember to remove the cap on the carb's bowl vent connection, whether you use it or not, failure to not have this vent open will result in a rich mixture and hot starting issues....the carb must be vented. Just my opinion of course.
BOB RENTON

 

[74Slant6Charger]

Regarding the choke pull off setting dimension.....try this: with the pull-off diaphragm under vacuum and the plunger spring extended, hold choke blade closed with a 3/8" or 7/16" drill bit between thr choke blade and
the airhorn wall adjust the U-shape link (open or close) on the pulloff connector for a slight drag....this will be close to the correct pull off opening.
Remember to remove the cap on the carb's bowl vent connection, whether you use it or not, failure to not have this vent open will result in a rich mixture and hot starting issues....the carb must be vented. Just my opinion of course.
BOB RENTON

Thank you, which cap Are you referring to?

 

[RJRENTON]

Thank you, which cap Are you referring to?

From your origional pix, there is a black cap or what appears to be a cap, on the carb's bowl which would be connected to a carbon canister or the valve cover breather, depending on the vehicle's year or engine. Since the 318 was transplanted its difficult to say what was origionally furnished.
BOB RENTON

 

[74Slant6Charger]

From your origional pix, there is a black cap or what appears to be a cap, on the carb's bowl which would be connected to a carbon canister or the valve cover breather, depending on the vehicle's year or engine. Since the 318 was transplanted its difficult to say what was origionally furnished.
BOB RENTON

Ah! Thank you... there is a carbon canister on the Core support, with an open port. Thanks!

 

[74Slant6Charger]

From your origional pix, there is a black cap or what appears to be a cap, on the carb's bowl which would be connected to a carbon canister or the valve cover breather, depending on the vehicle's year or engine. Since the 318 was transplanted its difficult to say what was origionally furnished.
BOB RENTON

Bob is that a Hemi-orange 70 GTX in your profile pic? My dad has one just like that... has had it since 84. Sweet car.

 

[RJRENTON]

Bob is that a Hemi-orange 70 GTX in your profile pic? My dad has one just like that... has had it since 84. Sweet car.

THANK YOU for your comment re the GTX. Its actually TORRED and needs repainted due to all the stone chips. I've owned it for 35+ years....i used to live in Pittsburgh Pennsylvania. Its one of 350 4 speed cars made with the 6 barrel engine (out of 678 total production). I invite you to look at my photo garage for a few more views. Its got a A34 Super Track Pack with Dana 60 and 4.10 gears, PS+PDB, max cool rad, etc
Thanks again...
BOB RENTON

 

[74Slant6Charger]

THANK YOU for your comment re the GTX. Its actually TORRED and needs repainted due to all the stone chips. I've owned it for 35+ years....i used to live in Pittsburgh Pennsylvania. Its one of 350 4 speed cars made with the 6 barrel engine (out of 678 total production). I invite you to look at my photo garage for a few more views. Its got a A34 Super Track Pack with Dana 60 and 4.10 gears, PS+PDB, max cool rad, etc
Thanks again...
BOB RENTON

Just checked out the pictures, very sweet! Love to hear that you’ve had it for so long.

 

[74Slant6Charger]

Hey guys!
Great weekend working on the Charger with the boy, we removed the intake, chiseled out the ports (wow), cleaned up and painted everything, reassembled it, and she fired right up! Choke working very well, car runs as good as it ever has. Really enjoyable experience, and the kid got some great hands-on work on his car. Very grateful for all of your input.

Joel

 

[RJRENTON]

Excellent....glad to hear that everything went well. Looking at your recent pix, its amazing that the exhaust cross over passage was full of carbon. Someone b4 you, removed the EGR valve (on ghe linkage side of the manifold) and put on a blank off plate. Most of the crud in the crossover passage could be attributed to EGRs operation or the engjne used a little oil which may be the cause of the carbon formation.
BOB RENTON

 

[74Slant6Charger]

Excellent....glad to hear that everything went well. Looking at your recent pix, its amazing that the exhaust cross over passage was full of carbon. Someone b4 you, removed the EGR valve (on ghe linkage side of the manifold) and put on a blank off plate. Most of the crud in the crossover passage could be attributed to EGRs operation or the engjne used a little oil which may be the cause of the carbon formation.
BOB RENTON

Engine definitely uses oil... where would the EGR valve return to - it looks like the little nipple on the EGR Valve is for a small hose... where does it go to?

 

[RJRENTON]

Engine definitely uses oil... where would the EGR valve return to - it looks like the little nipple on the EGR Valve is for a small hose... where does it go to?

The EGR system was designed to reduce NOx emissions by adding exhaust gas to the intake fuel charge via the EGR valve. The EGR valve was controlled by the carb's EGR vacuum port when the throttle is opened, which is different from the distributor's vacuum advance port. Sometimes, the EGR was controlled wia a thermal vacuum valve which inhibits the EGR valve from opening when the engine is cold. The addition of exhaust, via the EGR system, to the intake fuel charge to reduce the combustion chamber temperature to below 1600° F, which limits the formation of NOx or Oxides of Nitrogen. Best thing to do is do away the EGR system....the engine will run better without it. Just my opinion of course.
BOB RENTON