1970 Q-jet idle solenoid bracket

[G B.]

I need the two-piece bracket to mount the idle control solenoid on the Quadrajet of a 1970 454 with air conditioning. This bracket uses the front left carb mounting bolt.

Several years ago I tried to find this same bracket for a 1969 with a.c. I struck out and had to fabricate one. It seems there was once a nice reproduction sold by Chicago Corvette, but it isn't being made anymore.

Does anyone know of a current source for a used bracket or an old reproduction? This bracket was probably used on all '68 - '70 passenger cars with factory air and a Quadrajet. I'm surprised it's so difficult to find one.

[Dave S.]

Re: 1970 Q-jet idle solenoid bracket

Jerry, Is the bracket you need designed to hold a 434 TCS switch? If so aren't they integral to the switch itself? The 71 uses a 444 TCS/CES switch which does require a seperate bracket.

[Jack H.]

Let your fingers do the walking....

Bracket is still in stock (available to order) at your local United-Delco dealer along with the solenoid 'French lock'. Was made by Rochester Products. One version for Q-Jet, another for Holley. Brackets and locks have an abbreviated RP part number stamped into them that lacks the 'understood' first digit that points to RP as the source.

The French lock is RP ?42653 and the Holley bracket is RP ?42662. The Q-Jet bracket will be 'close' in PN to the Holley (don't have one in front of me) --have the United Delco counterman crack a carburetor parts book for correct/full PN....

Unfortunately, the BIG gold dichromate solenoid mounting nut is long gone. It superceeded by a functional equivalent that looks MUCH different (cheap/thin sheet metal stamping). Don't recollect if they still have the bracket-carb hold down screws with the wide shoulders in black oxide finish, but you can check.

[G B.]

I wasn't very clear

I appreciate you guys trying to help. I just wasn't clear enough about what I need.

In 1970, the idle control solenoid was still separate from the TCS. The TCS controls vacuum to the distributor. The 434 TCS mounts on an intake manifold stud using an integral bracket. The idle control solenoid mounts on the carburetor. From 1968 to 1970, the idle control solenoid only increased idle speed when the a.c. compressor was on. After 1970, I believe GM started using a CEC solenoid that did this and also controlled vacuum.

The '68 - '70 idle solenoid was attached to the carburetor with a two-piece bracket that tightened around a smooth solenoid body. In 1971, GM started using a bracket that held a threaded solenoid with a large thin nut. This second design bracket is the one that is still available. The large nuts are still sold by Holley and others.

The smooth, unthreaded, '68 - '70 idle solenoids are readily available aftermarket and NOS. The bracket to hold this animal is the tough part.

[G B.]

Even more clarification

I talked to Chicago Corvette today. They said the old reproduction '68 - '70 idle stop bracket tooling belonged to ASL. Nobody has seen any reproductions of this bracket since they quit doing business with ASL. CVS said that they now use a bracket manufacturer who could make copies of an original bracket in 4 weeks time. Of course, I would have to supply an example.

This idle stop solenoid bracket was used on most Chevrolet products with a Quadrajet and factory air from 1968 through 1970. There were actually three pieces to the set-up. The largest piece was the main bracket. It attached to the carb body under the left front mounting bolt. The second piece was a curved strap that bolted to the main bracket and encircled the solenoid to squeeze it. The third part was a little L-shaped piece that bolted to the carb throttle arm to provide a bigger target for the solenoid stop plunger. I don't think Pontiac used this same bracket design. I'm not sure about Cadillac and Olds.

In 1971 Chevrolet went to a combined idle stop and vacuum control called a Complete Emissions Contol (CEC) solenoid. This used a different bracket to mount on the carb. I believe Chevrolet went back to a separate idle stop solenoid and Transmission Control Vacuum switch set-up in 1972. After that, I get real confused.

[Thad L.]

Re: Even more clarification

Jerry, I have to disagree with you on the brackets application. Terry McManmon may be able to help, but no 70 LS-5 cars with A/C had an idel up bracket and solonoid assy. The only thing diffrent was a deceleration valve that used the idel screw hole and kept the butterflies from closing too fast and stalling. I have owned 2 70 LS-5's both with A/C and there were no other A/C solonoids to bump the idel up! Hope this may help a bit. Thad LeJeune

[Erv Schlepp]

Re: Confirming Even more clarification

I have a 70 454 with 4-speed and AC and it does not have an idle solenoid nor have I seen one in the AIM. I have had the car judged and this was not an issue.I believe you are seeking a part that was never used. Chicago Corvette has some good people and some that would not know these facts.

[Thad L.]

Re: Confirming Even more clarification

Erv, I am keeping a little record for my own info, does your car have the deceleration valve as an idel stop? Also, your choke rod, is it held onto the carb with a horse shoe type clip or a clamp type that the JG shows as correct? thanks Thad

[G B.]

I need more help than I know

I'm outside the envelope of my technical knowledge here.

I've been basing this bracket search on my own assumption. I saw the L36 idle solenoid sheet in the '69 AIM, the LS5 idle solenoid sheet in the '70 AIM (marked cancelled), and the LS5 CEC solenoid in the '71 AIM. I assumed from this "series" that there was some kind of idle solenoid used on big block a.c. Corvettes throughout the 1970 model year.

I do have a 1993 issue of the '70-2 judging manual, but it isn't helping me much on this subject. At least it explains the terminology. It says CEC means Combined Emissions Control. I always thought a TCS was TEMPERATURE Controlled Solenoid, but this judging manual calls it TRANSMISSION Controlled Spark. Shows what I know.

Thanks for the input from those who know about these cars. Obviously I don't.

[Terry M.]

some help *TL*

Jerry,

In 1970 and 1972 TCS= Transmission Controlled Spark. In 1974 (at least with auto transmission) TCS= Temperature Controlled Spark. I'm not sure about 1973 or other years. Chevrolet's love of acronyms rivals that of the computer industry.

Some 1969s w/C60 had the throttle kicker solenoid you refereed to, but to the best of my knowledge no 1970s. That is not to say that it would not improve driveability, especially with C60/M40 combined.

Terry