C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

1971 Idle Selenoid question

Thread Tools
 
Search this Thread
 
Old Dec 18, 2012 | 05:19 PM
  #21  
Alan 71's Avatar
Alan 71
Team Owner
15 Year Member
Active Streak: 120 Days
Community Influencer
Top Answer: 5
 
Joined: Sep 2006
Posts: 31,280
Likes: 4,372
From: Westminster Maryland
Default

Hi Stan,
My original solenoid is in the Northern Carroll County Land Fill waiting to be found in a few thousand years.
I bought a service replacement quite a few years ago.
Here's a close-up of the picture on the instruction sheet that came in the box for that solenoid, and a couple more of the solenoid itself.
Are you looking for a detail in particular?
I continue to be curious about the configuration of the delay relay used during 71 production... there seems to be at least 2. Working reversing and delay relays are interesting to find.
I'll send you an update on the dealer.
Regards,
Alan





Terry M. pointed out that the end of the vacuum pipe is sized to slip into the nylon nipple on the solenoid.... and it does.
Reply
Old Dec 19, 2012 | 10:58 PM
  #22  
Rowdy Rat's Avatar
Rowdy Rat
Safety Car
Veteran: Marine Corps
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 3,604
Likes: 839
From: PA
Default

Originally Posted by Alan 71
Hi Stan,
My original solenoid is in the Northern Carroll County Land Fill waiting to be found in a few thousand years.
I bought a service replacement quite a few years ago.
Here's a close-up of the picture on the instruction sheet that came in the box for that solenoid, and a couple more of the solenoid itself.
Are you looking for a detail in particular?
Thanks for the photos Alan.

Yes... In particular, I am interested in the label at the moment. My original looks to be a lot like the one in Jerry's photos. The NOS one is exactly like yours. The reproduction is similar to the service part, but still a bit different. I plan to make an accurate repro label, but I need to be absolutely sure that what I am using is correct. My current sample size is one... I'd like a few more before committing the resources to this project.

I continue to be curious about the configuration of the delay relay used during 71 production... there seems to be at least 2. Working reversing and delay relays are interesting to find.
I can tell you that the original Holley stuff is getting tough to find. I have an original, an NOS, and a reproduction. They are all different to varying degrees.

I'll send you an update on the dealer.
Thanks again Alan!

Regards,

Stan
Reply
Old Dec 20, 2012 | 08:32 AM
  #23  
Alan 71's Avatar
Alan 71
Team Owner
15 Year Member
Active Streak: 120 Days
Community Influencer
Top Answer: 5
 
Joined: Sep 2006
Posts: 31,280
Likes: 4,372
From: Westminster Maryland
Default

Hi Stan,
The labels are a bit of a mystery to me. There are so many versions.
I may have related to you that when I bought the solenoid I presently have there was a label on the solenoid, an extra label was in the box, and the picture on the instruction sheet showed a solenoid with a label... all 3 were different.
If I can contribute to the label effort in any way... info (label size, font style, and size), labor, or financial, I'd like to. I'm not really happy with what's on my solenoid now, (please don't ask why), and would love to have a better reproduction.
I'm also including this label from a car at Wildwood... I think it's a nice example of the horizontal version.
Again, if I can help this effort I'd like to.
Regards,
Alan

Reply
Old Sep 27, 2016 | 07:44 PM
  #24  
71SoCal's Avatar
71SoCal
Racer
15 Year Member
 
Joined: Apr 2005
Posts: 339
Likes: 1
From: San Diego CA
Default

I love this forum! Just do a search, and someone else has already thought about it!
A few weeks ago, I started thinking again about the CEC/Idle Solenoid on my 1971 350/270 a/c 4-spd car.
When I run the a/c on my car, the rpm’s drop by about 300, and the car can barely idle. I started thinking that I could correct that by adding the solenoid into my car and it would bump the rpm when the a/c turns on (I don’t have a solenoid installed right now).
I did a bunch of research and learned that the CEC system won’t solve this problem. I love the idea of making my car correct and restoring the CEC system to original condition, but how do I make my car operate correctly when the a/c is turned on?
Is a 300 rpm drop with the a/c turned on a normal thing, or should I be looking somewhere else for the problem?
Reply
Old Sep 28, 2016 | 09:37 AM
  #25  
Alan 71's Avatar
Alan 71
Team Owner
15 Year Member
Active Streak: 120 Days
Community Influencer
Top Answer: 5
 
Joined: Sep 2006
Posts: 31,280
Likes: 4,372
From: Westminster Maryland
Default

Hi 71,
I don't think you're the first person to have this situation.
Here's a discussion about what you describe. It's taken from the NCRS archives and is written by someone with far greater understanding about a/c than I.
???
Regards,
Alan

The Chasis Service Manual's theory of operation text regarding the CEC system 'hints' at a different curb idle setting for A/C equipped cars, but the tune-up sticker on the Corvette and service text does NOT document one. The CSM says:

"To prevent dieseling on air conditioned vehicles with automatic transmission, which is caused by the LARGER throttle angle required when setting idle with the air conditioning on...."

Then, they go on to describe the special relay set that engages the A6 compressor, regardless of cockpit control setting on engine shut down. This is reinforced in the 1971 CEC Dealer Training Program Booklet. There, they single out Chevelle, Nova and Corvette vehicles equipped with AC (regardless of manual vs. automatic transmission) to describe the companion smart relay set.

"I 'think' you have to bump curb idle above factory indicated specs on a 1971 AC equipped Corvette to prevent stalling during idle. And, the degree you have to 'boost' curb idle is tricky. It depends on the drag coefficient of your compressor (do you have the real McCoy small displacement A6 or do you have a generic passenger car compressor installed?). Also, if you bump curb idle TOO much, you'll 'tickle' the low end of the factory stock distributor's vac advance engagement.... This can be a devil to diagnose!" Jack Humprey.
Reply




All times are GMT -4. The time now is 10:30 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE