While starting to tune my engine with an O/2 kit, I have found that once I get my Neutral O2 reading around 14.0 or so, this kills the Spring time cold start process by leaning out the engine too much and the cold start is just a fight to keep the engine running due to the O2 readings jumping into the 16-18 range "after" the choke opens and before the engine is up to running temp.

After several attempts to get my automatic choke to delay long enough to allow the engine to get some heat but also not shutting the choke plate to far to choke out the motor on a cold start, I am looking into delaying the opening rate of the choke.
After reading some of the replies to another thread, I am looking to see if anyone on the site has tried the Holley Choke Delay Kit #45-267.
This kit is supposed to use the heat from an intake mounting bolt to slow down or speed up how much current gets to the electric choke. If I am understanding the workings of this unit, the cold temp from the manifold bolt (cold start) will slow down the current going to the electric choke which will slow down the opening rate while allowing a leaner choke setup at the same time. When the intake bolt is warm (during engine cool down), the unit will speed up the opening rate of the choke which is not needed when the engine is warm.
This makes sense and this is what I am after, but I wanted to see if anyone has tried this Holley #45-267 unit and if you have, please let me know how it worked for you.

Note:
I know that Jim and some others have come up with their own genius way of making this device, but I am looking for a "quick fix" that I can buy in the next day or two and test over the weekend.

Thank you,

Yes, I used one back in the day. In the early-mid 80's, I had a '78 440 cop car with a 3310 that was my daily driver. My choke did exactly what yours is doing, so I added one of these gizmos.

They work, but the only way to tune it is to move it around on the engine - from areas that warm up quickly, such as a center intake manifold bolt, to areas that warm up slower. If you can find an area that warms up at a rate that makes this a match to your choke, you're done.

The reason I use a normally open temperature switch is for tuneability (is that a word?). You can change the resistor value (or use a rheostat), change the temperature rating of the switch, and move it around on the engine.

Once you tune out the pig-rich cruise on a Holley, your car becomes a cold-natured beast, huh?

Jim

Jim,
I was hoping that you had experience with this unit.

I am running the aluminum RPM intake which has a couple of raised boss's on the intake with tapped holes (higher up than the intake mounting bolts which puts the sensor closer to the carb mounting height.) in it which I am planning on using for the connection. I was thinking if I need to tweak it a little, that I could use nylon washers to test with to see if that delays it even more if required.
With the choke applied (for only a few seconds it seemed), I was getting mid 13 readings and it started right up and sounded good. Then the s**t hit the fan when the choke opened and the gauge went straight to 17-18 and it was a dog fight at that point to keep it running. I jumped out and turned two of the metering screws outward a tad and that helped, so I know for sure that it is just too lean during this time of the warmup procedure.
If this gadget works for only a short amount of time, then I think that this will get me thru the cooler temps that we have right now and it will also allow the leaner Neutral O2 readings that I am after too.

In the above kit, what is the affect of the shrink tubing on the choke tang? Is this an insulator for something?
EDIT:
During the install, I did confirm that this sleeve needs to be applied to make the stock choke electrical circuit (negative) void.
I feel that the best place to install the sensor is on the thermostat housing, which is as close to the coolant as possible. But I am not sure if it matters that much as long as it is on a hot engine surface.

Note: I am using a Quick Fuel carb that has "changeable everything" on it and that is helping me with some of the tuning so far. Once I get passed this cold start lean condition, then I will get it on the street and work on the rest of the carb tuning.

Thank you for your reply.

I installed the Holley Choke Delay kit to try and lengthen the amount of time that my electric choke stayed on due to leaning out the carb for the O2 kit. The last time I tested the choke, it was 64 degrees outside and I had the choke set at the #6 mark from the front. After a cold startup, the choke came off about 20 seconds or so and the O2 gauge spiked up to 17-18 (lean).
I installed the kit and left the carb as setup on my previous cold start, and a couple of pumps of the pedal and it fired right up in 42 degree temps and at 1200rpms, it was idling a little rich in the 11.8-12.2 range. After about two minutes or so, the idle started up to 1300rpms and the gauge read around 12-12.4 as the choke started opening. Then the gauge went to 14 and the rpms were at around 1400rpms and the engine temp was on the first mark. In my situation, the choke delay kit worked great! My carb is still fairly lean in N and the cold startup went great.
I am going to lean out the choke to the #5 position and try it again to see if I can get the early startup to read in the low 12's instead of high 11's.

I tested the delay with the choke set at the #5 setting from the front on a 67 degree day. Two pumps of the pedal and the car fired up in the mid 13's on the O2 guage at 1200rpms. I put a timer on The Holley choke delay and the choke delayed right at 1 minute and 30 seconds. This was excellent for my current setup.
I just wanted to pass this along.

UPDATE:
I found my reason for needing the choke delay. While using the O/2 sensor to tune my transition circuit, I found it very lean. Once I had my transition circuit fixed, I then found that I did not need the choke delay. The choke delay was great for cold starts but I found during warm restarts, it was still delaying the choke and my A/F readings were 16-18 and I could not keep my engine running due to this, even with a warm engine.
I am now running the stock Quick Fuel electric choke and I found the the #7 mark from the front is fine in mid 60 temps.