Correct idle solenoid for '72 LT-1?

[Kenneth L.]

I have a '72 LT-1 with A/C. Is the correct GM idle stop solenoid part number - 1114450? I couldn't find the # in my assembly manual. I'd also like to know what the wire feeding it looks like, so I can search for it. I assume that it kicks the rpm up when the A/C compressor is turned on.

[Edward J.]

Re: Correct idle solenoid for '72 LT-1?

Ken, my 72 air car has a tan wire for the solonoid, and not sure on the part no. but I did recently see a new solonoid on e/bay. maybe Joe L. will chime in.

[Joe L.]

Re: Correct idle solenoid for '72 LT-1?

Ken-------


I'm not sure on this one. The original SERVICE part for 1972 Corvette with LT-1 and GM #3999263 carburetor was a solenoid UNIT of GM #6273914. The UNIT consisted of a solenoid and other parts. Which solenoid was included with this unit I do not know.

The 6273914 was discontinued from SERVICE in September, 1977 and replaced by GM #1997409. That was discontinued and replaced by GM #1997470 in July, 1982. Then, the latter was discontinued and replaced by GM #17111376 in March, 1988. GM #17111376 is now discontinued, too.

As you can see from the above, GM #1114450 is nowhere to be found in the series of part numbers. However, I can tell you this: GM #1114450 was once available separately in SERVICE but not cataloged for a Corvette application. Curiously, it was discontinued in February, 1975 and replaced by GM #1997409, the same piece that replaced the 6273914. It is very possible that the 1114450 was the solenoid originally used for 1972 LT-1 applications and supplied as part of the GM #6273914 solenoid UNIT.

[Edward J.]

Re: Correct idle solenoid for '72 LT-1?

Joe, that number almost looks the number for the TCS. emisson control solonoid?(1114450)

[Joe L.]

Re: Correct idle solenoid for '72 LT-1?

Joe, that number almost looks the number for the TCS. emisson control solonoid?(1114450)

Edward------


The GM #1114450 was an idle stop solenoid. However, it may also have had some TCS functionality.

Upon a little further research, I have also found that the 1114450 was cataloged for a brief time for Corvette applications. That application was 1972 Corvette with Rochester carburetor. However, it still might have been the solenoid supplied as part of the 6273914 solenoid UNIT for 1972 LT-1 applications.

[Dick W.]

Re: Correct idle solenoid for '72 LT-1?

Joe, et al, the 450 solenoid is shown in the Delco Remy application catalog as being correct for a 1972. Now if we can believe that catalog you have the correct solenoid. It should be about 3"-4" long plus the plunger and 1 1/4"- 1 1/2" in diameter. I have one somewhere around here, if I can find it I will give you the exact measurements. The solenoid is the easy part, the Holley mounting bracket and the french lock for the mounting screws will be the hard part to find.

[Joe L.]

Re: Correct idle solenoid for '72 LT-1?

Joe, et al, the 450 solenoid is shown in the Delco Remy application catalog as being correct for a 1972. Now if we can believe that catalog you have the correct solenoid. It should be about 3"-4" long plus the plunger and 1 1/4"- 1 1/2" in diameter. I have one somewhere around here, if I can find it I will give you the exact measurements. The solenoid is the easy part, the Holley mounting bracket and the french lock for the mounting screws will be the hard part to find.

Dick-----

I have no doubt that the 1114450 will work for any 1972, including LT-1. However, what I don't know is if it was the solenoid originally used for 1972 LT-1's and supplied as part of the 6273914 SERVICE UNIT. Most likely, it was but I don't know that for sure.

[Kenneth L.]

Re: Correct idle solenoid for '72 LT-1?

Should it look like this?

[Kenneth L.]

Re: Correct idle solenoid for '72 LT-1?

Dick-----

I have no doubt that the 1114450 will work for any 1972, including LT-1. However, what I don't know is if it was the solenoid originally used for 1972 LT-1's and supplied as part of the 6273914 SERVICE UNIT. Most likely, it was but I don't know that for sure.

Hey Joe - PM sent.
Ken

[Joe L.]

Re: Correct idle solenoid for '72 LT-1?

Should it look like this?

Kenneth------


This appears generally correct to me. However, I could not say if it's EXACTLY correct. Usually, these solenoids have a GM part number either embossed or ink-stamped on the cylindrical body. If it was ink-stamped, it could be gone by now if this is a used piece.

[Jack H.]

Re: Correct idle solenoid for '72 LT-1?

BTW, the idle stop solenoid that mounts on the LH side of the carb does NOT bump engine RPM to compensate for A/C compressor loading...

The compressor runs full time when the A/C is engaged and the freon flowing to the evaporator is throttled to maintain temperature.

The job of the idle stop solenoid is to control the car's emissions profile in conjunction with the vacuum switching solenoid on the RH side of the carb (intake manifold mounted) that feeds vac to the distributor (TCS).

As others have said, the idle stop solenoid is a pretty simple unit that was rubber ink stamped with its GM PN. You probably won't find it in the AIM because the factory got their carbs from Rochester/Carter with the idle stop solenoid already installed.

I don't know about Holley...the solenoid mounting bracket was a different animal.

On pictures shown by others, my recollection is the right angle electrical connector was common to the pre-71 era, while later factory solenoids ('72) featured a straight-back geometry terminal...

[Dick W.]

Re: Correct idle solenoid for '72 LT-1?

Kenneth------


This appears generally correct to me. However, I could not say if it's EXACTLY correct. Usually, these solenoids have a GM part number either embossed or ink-stamped on the cylindrical body. If it was ink-stamped, it could be gone by now if this is a used piece.

I have never seen a solenoid in that era stamped. All that I have ever seen were ink stamped, easy to duplicate.

Joe, the D/R applications book I used is dated 1972 so that it has a fair chance of being correct. I used to buy an identical solenoid from Standard, the only difference being the lack of the D/R number, BUT the last time I ordered one, it was the short replacement version.

[Kenneth L.]

Re: Correct idle solenoid for '72 LT-1?

Thanks for the help. I just bought both the TCS and idle stop solenoid for the LT1 on ebay. Both are N.O.S. GM parts, so they seem correct. I found my brown wire for the idle stop solenoid connected to the electric choke on the (incorrect) Holley 3310 carb. So I also ordered the factory choke coil, cover, and lever to return that back to stock. Then I'll steal the solenoid lead back. I found the Holley idle solenoid bracket and nut at Corvette Central, as well as the mounting stud for the TCS solenoid and (repro) greeen TCS lead.

Will this green lead connect the TCS solenoid, engine block temp sensor, and trans sensor together? Then after connecting the vacuum lines in line with the solenoid, it should be working, I assume. But how do you know?

[Bryan M.]

Re: Correct idle solenoid for '72 LT-1?

Ken,
Check out this thread. It has some good pics. I bought some hex head mounting bolts and the french locks for the bracket from Holley.
https://www.forums.ncrs.org/showthread.php?t=61093

http://www.holley.com/20-72.asp

[Kenneth L.]

Re: Correct idle solenoid for '72 LT-1?

GREAT pic and info. Thanks for digging that up Bryan. This is the Holley idle solenoid bracket that I ordered from Corvette Central. It appears to match the one in that pic (if it's original).

I have a pair of holes in the base plate of my Holley 3310 carb, but only the right hole is threaded. Is this why the pic on that old thread shows what appears to be a pin (no hex head) on the left and a bolt on the right? This seems odd. Is there some kind of a pin that you tap in?

I'd like to see the same quality detailed pic of the other side, showing the TCS solenoid and carb choke. I'm going to convert my electric choke back to stock and I'm waiting for my TCS and mounting stud to arrive also.
Ken