Idle at 1000 plus

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my65
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Idle at 1000 plus

Post by my65 »

I just bought a 1963 coupe with a 1965 140 hp motor in it. And I need some help on this one?
The car bucks hard when you are going around 5-20 mph so you have to slip the clutch to smooth it out. Then it bucks slightly when you are on the road at 1800-2000 rpm.
The previous owner replaced the original carbs with a high preformence set from Wolf's so I thought today would be adjustment day!!
After removing the air cleaners, I saw that the linkage was binding in several locations. Most was corrected by adjusting the turnbuckles and moving the connection from one side to the other. The exception was the left side primary carb choke linkage and the throttle turnbuckle. To get some clearance, the cross shaft lever would need to be bent ! Is that normal??

Moving on...... the vacuum from the right primary carb was rerouted to a vacuum gauge and the distributer vacuum blocked off. The timing was 10 degrees out and corrected to 16 degrees btdc. The dwell is 18 and controlled by a electoral pickup. The carborator mixing screws were at 3 1/2 turns out and that was corrected to 1 1/2 turns out. The motor was started and the vacuum gauge needle was rapidly bouncing in a small range and the motor was 1200 rpm idle. Several adjustments were make back and forth between the mixing screws and idle screws on both carbs. I could get the idle to 800rpm or a steady vacuum but NOT at the same time unless rpm was 1000
Do my carbs have the wrong jets or do I just not know how to do this?!? :dontknow:
Attachments
IMG_0321.JPG
IMG_0327.JPG
IMG_0328.JPG
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Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
my65
Posts: 155
Joined: Tue Dec 01, 2015 12:20 pm
Location: porter texas

Re: Idle at 1000 plus

Post by my65 »

Forgot this one
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Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
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bbodie52
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Re: Idle at 1000 plus

Post by bbodie52 »

:think: I am not sure what is causing the idle to be so high on your engine. At that high idle speed it would be difficult to accurately adjust ignition settings and carburetor idle speed settings. I think I would backtrack a little to confirm that all cylinders are mechanically sound — before proceeding with a tuneup series of adjustments. Have you pulled the spark plugs and check the compression on each cylinder? If you run a compression test, you should also examine each spark plug to see if they all appear to be burning equally, or if one or more cylinders is showing signs of a mismatch or problem area.

I would also recommend carefully checking all vacuum hoses and lines to make sure that there are no vacuum leaks. I noticed that it appears that the vacuum line for the PCV system fixed orifice is disconnected and plugged. The fixed orifice vacuum port should be examined and cleaned and then reconnected to the vacuum balance tube. This is part of the final operating configuration and should not be disconnected from the system when you go through the process of synchronizing and adjusting your carburetors.

Image

You should disconnect the secondary carburetor linkages and ensure that the secondary throttle butterflies are completely closing. The accelerator pump assembly includes a spring that helps to exert pressure on the throttle linkage to keep the secondary carburetors fully closed unless they are opened by the main throttle linkage. By temporarily disconnecting the secondary carburetors and ensuring that the throttle butterflies are fully closed you are removing any problems with them from the system while you focus on synchronizing and adjusting your primary carburetor idle speed. (Sticking secondary throttle butterflies that do not fully close when the secondary carburetors are not operating is effectively a vacuum leak that could be impacting all of your remaining settings. Depending on your driving habits, secondary carburetors may see little operation and could accumulate dirt and other deposits on the throttle assembly that might prevent the secondary carburetors from fully closing when they are idle).

The initial settings of the primary carburetor idle mixture and idle speed screws should be physically set in accordance with the shop manual. This can be done with the linkage that ties the carburetors together temporarily disconnected. You want to establish the two idle speed screws settings at 1½ turns beyond the point where they make initial contact with the carburetor linkage. The shop manual procedure describes using a strip of paper to detect when the screw first comes into contact with the carburetor throttle linkage, and then adding one 1½ turns to establish the initial idle speed setting, which would be mechanically the same for each primary carburetor. The idle mixture screws should be lightly bottomed out and then backed out 1½ turns.

With these initial settings at the carburetors, and with the engine warmed up and operating at normal temperatures, you should be able to confirm that both choke assemblies and their associated fast idle cams are fully disengaged. If there are no vacuum leaks and the carburetors have been been mechanically synchronized, the idle speed should be slow enough (600-650 RPM) to eliminate any possibility of the ignition timing being advanced by either the vacuum advance or centrifugal advance. You should confirm the timing with a timing light of the vacuum advance temporarily disconnected from the distributor. Timing should be 16°-20° BTDC. At this point the engine idle should be close to the desired range. Final idle synchronization can then be accomplished with the UniSyn gauge. Another indicator of proper operation of the carburetors can be checked by checking the dual exhaust output. The exhaust sound and the amount of heat from each exhaust tailpipe should be fairly even.

The cross linkage between each primary carburetor should then be reconnected, while carefully checking that none of the linkage is binding. A turnbuckle can be used to hold the throttle open to approximately 1200 RPM. The linkage can be adjusted at the left carburetor while measuring airflow through each primary carburetor with the UniSyn gauge. Part-throttle airflow should be matched between the two primaries by adjusting the throttle linkage at the left carburetor.

Click on the link below to read another article on carburetor synchronization and use of the UniSyn gauge...

:link: http://www.corvairforum.com/forum/viewt ... kle#p89750

The final step would be to check the linkage and reconnect it at each secondary carburetor. The linkage operation and adjustments are described on page 12 of the attached DELCO ROCHESTER - Models H, HV Carburetor Service Manual.
Attachments
DELCO ROCHESTER - Models H, HV Carburetor Service Manual.pdf
DELCO ROCHESTER - Models H, HV Carburetor Service Manual
(1.79 MiB) Downloaded 75 times
1965 Corvair Chassis Shop Manual - SECTION 6 - ENGINE TUNE-UP.pdf
1965 Corvair Chassis Shop Manual - SECTION 6 - ENGINE TUNE-UP
(2.92 MiB) Downloaded 55 times
1965 Corvair Chassis Shop Manual - SECTION 6M - ENGINE FUEL.pdf
1965 Corvair Chassis Shop Manual - SECTION 6M - ENGINE FUEL
(8.87 MiB) Downloaded 58 times
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
my65
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Re: Idle at 1000 plus

Post by my65 »

Thank you Brad for the input. I will try it today or over the weekend.

Any ideas on the misalignment of the cross shaft rod and the left primary choke linkage ( see first picture) ???
Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
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bbodie52
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Re: Idle at 1000 plus

Post by bbodie52 »

When comparing your photograph of the left carburetor linkage with an illustration from the attached 1965 Corvair Assembly Manual - CARBURETOR & FUEL SYSTEM, there appears to have been modifications to the linkage on your car. The arrows in the first picture point to two nonstandard components on your throttle linkage. The two illustrations in the first picture below show the left and right linkage components between the cross-linkage and the carburetor throttle linkage. The right component is nonadjustable, but the component on the left side has an adjustable swivel on the bottom. The link on the left is the one that allows you to synchronize the airflow through each carburetor when measured with a UniSyn gauge. By using a turnbuckle device to hold the main throttle opened so that the engine runs at approximately 1200 RPM, the left side linkage component can be adjusted in length using the swivel at the bottom so that the airflow is matched between the left and right primary carburetors.

In any case, any modifications that have been made to the original factory linkage may be injecting problems in the operation of the throttle linkage on your car. Changes in the geometry and shape of the various components could be causing binding and may be preventing smooth operation of the two carburetors through the throttle linkage range of motion.
Linkage Mods.jpg
The upper choke rod on left carburetor in the second photograph does not appear to have the same bends in it as the one in the illustration. The difference in angles and lengths of the various segments in the choke rod may be the source of problems that you might be having with the choke linkage on the left side.
Choke Linkage Mods.jpg
Attachments
1965 Corvair Assembly Manual - CARBURETOR & FUEL SYSTEM.pdf
1965 Corvair Assembly Manual - CARBURETOR & FUEL SYSTEM
(3.92 MiB) Downloaded 51 times
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
my65
Posts: 155
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Location: porter texas

Re: Idle at 1000 plus

Post by my65 »

Just a short update, I only had an hour before I had to leave for granddaughter's softball game⚾️
The PO changed out heads, carbs, and linkage going from 110 hp to 140 hp. The linkage for throttles came from Clark's (still sell it) but I do not know about choke.
I removed linkage from secondaries and the cross shaft from the primaries. Adjusted mixtures to 1 1/2 turns out but could not get my large fat hands into idle lever for initial setting😩.
Found the cross shaft was holding primaries open slightly so adjusted and reconnected. Started engine and adjusted Idle screws to keep it running. Set timing and adjusted and got idle down to 800rpm but lower than that it stalled. Removed gauges and took it out for test. Acceleration is pretty smooth but if I release the gas pedal at 20 mph, there is a slight jerking until you apply some gas pedal🤔😨
85% improvement but I am soaked, need a shower and off to the game!!!
Oh yea, the right muffler is smooth but the left one has an irregular putting ??
Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
my65
Posts: 155
Joined: Tue Dec 01, 2015 12:20 pm
Location: porter texas

Re: Idle at 1000 plus

Post by my65 »

Today, I tried to get the car ideling smooth but I failed! I rechecked the timing, linkage, checked for vacuum leaks, reset mixture, and doubled checked spark plug wire connection, checked compression ( had 129 ) BUT still can not get a smooth idle or under 800rpm.
I did not mention in my earlier posts that the PO replaced the points with an electrical pickup, and all four carborators with Wolfe rebuilt ones.......could that be my problem?
Am I missing the obvious .. :banghead: :banghead: .. what should I try next??
Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
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bbodie52
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Re: Idle at 1000 plus

Post by bbodie52 »

:think: Are you by any chance running an engine that is fitted with a Pertronix Ignitor II electronic ignition? There has been a problem noted in the past with the Pertronix II where half the cylinders electronically drop out at low idle speeds with a Powerglide transmission. This is apparently not a problem with the original Pertronix I electronic ignition. For this reason the Pertronix II is not recommended for use on the Corvair with a Powerglide transmission. The symptoms you describe could reflect a loss of every other cylinder at slow idle speeds with the transmission engaged in DRIVE. Under these circumstances when the transmission was shifted back to neutral the idle speed might increase just enough to reengage the missing cylinders, which might cause the idle speed in NEUTRAL to race to a much higher rpm.

The make and model of the electronic ignition system, and how it is wired to the power source is important. A Pertronix electronic module MUST be powered by a full 12 VDC source to provide adequate voltage to the electronic circuits. If the installer simply tapped into the voltage feed to the coil, the ballast resistor wire may still be in the circuit, which would drop the voltage down to a nominal 7 VDC which can cause the electronic module to malfunction. If you have a Crane Cams XR700 electronic system, it is designed to operate with the reduced voltage provided by the primary system with a ballast resistor in the circuit. (In fact, it may overheat if the electronic module is powered by a full 12 VDC).
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
my65
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Re: Idle at 1000 plus

Post by my65 »

The car has a Pertromic ll igniter so back to the beginning.
I spoke to Wolfe carborators yesterday and he got me thinking of the linkage, again! My engine is a 1965 which according to Clark's, the cross shaft is a (c9764) it's different than 1966-69 (c9765) Does anyone know what that difference is?
I disconnected all linkage from all carbs and found the right secondary would sometimes hang up when the cross shaft went back to idle.
I found the rotor contact protruded .046 and a new one was .053 so I will replace it and the distributor cap. I am going to replace plugs with NKG B5RHS , test wires and replace if needed. I will recheck each cylinder's compression, and double check #1 TDC piston matches distributor rotor and timing marks alignment. After all this is confirmed to be correct, I will try to adjust the primary carbs to get my idle down to a smooth 700!?!?!
I hope by then to be able to confirm the linkage, reassemble and go on to the next task!!

Any help with linkage??
Did I miss something to check, adjust??
Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
66vairguy
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Re: Idle at 1000 plus

Post by 66vairguy »

Based on trial and error by others, the lowest recommended RPM with the Petronix II is about 900 for a smooth idle. This is why I use the Petronix I, ballast resistor, stock coil for non turbo applications. More than adequate.

Yes the secondaries can stick open. Clark's sells an optional return spring that goes on the throttle shaft. Also I would check out poster "rip11" on the Corvair Center forum. He sells a great linkage. I prefer the 65 style as it's much easier to set up, BUT if you have 66 carburetors you'll need to disable or remove some parts to use the 65 style linkage.

Brad made some good observation about your PCV system. Improperly set up it can result in a fast idle condition.
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66corsaguy
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Re: Idle at 1000 plus

Post by 66corsaguy »

bbodie52 wrote::think: Are you by any chance running an engine that is fitted with a Pertronix Ignitor II electronic ignition? There has been a problem noted in the past with the Pertronix II where half the cylinders electronically drop out at low idle speeds with a Powerglide transmission. This is apparently not a problem with the original Pertronix I electronic ignition. For this reason the Pertronix II is not recommended for use on the Corvair with a Powerglide transmission. The symptoms you describe could reflect a loss of every other cylinder at slow idle speeds with the transmission engaged in DRIVE. Under these circumstances when the transmission was shifted back to neutral the idle speed might increase just enough to reengage the missing cylinders, which might cause the idle speed in NEUTRAL to race to a much higher rpm.

The make and model of the electronic ignition system, and how it is wired to the power source is important. A Pertronix electronic module MUST be powered by a full 12 VDC source to provide adequate voltage to the electronic circuits. If the installer simply tapped into the voltage feed to the coil, the ballast resistor wire may still be in the circuit, which would drop the voltage down to a nominal 7 VDC which can cause the electronic module to malfunction. If you have a Crane Cams XR700 electronic system, it is designed to operate with the reduced voltage provided by the primary system with a ballast resistor in the circuit. (In fact, it may overheat if the electronic module is powered by a full 12 VDC).
Brad. I ordered distributor rebuild kit for my 66 manual Corsa when I opened I noticed previous owner replaced with igniter 2 ( I should have known from flame thrower but I am a beginner)
Since I am rebuilding should I pull and get ignitor 1? I am reading a lot of problems with the 2 thanks for any advice

I am willing to buy new distributor or whatever is recommended.


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bbodie52
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Re: Idle at 1000 plus

Post by bbodie52 »

I have not had personal experience with the reported problem of combining the Pertronix Ignitor II with an automatic transmission based Corvair engine. But the reports that I have read seems to indicate that the Pertronix Ignitor II has a difficult time with interpreting the magnetic pulses from the distributor at an ultra-slow idle speed. Apparently the system electronics cannot properly trigger the ignition coil discharges when the engine slows beyond a certain threshold. With the Powerglide automatic transmission in DRIVE, the load imposed on the engine by the torque converter slows the idle speed just enough to disrupt the function of the Pertronix Ignitor II. I have not heard this problem reported with the older model Pertronix Ignitor I.

It might be worthwhile for you to contact Pertronix Technical Support at :link: http://www.pertronix.com/support/. Click on Support Ticketing System and open a new ticket. Leave a description of the issue you are experiencing and the reported information you have received regarding the Pertronix Ignitor II with a Corvair engine coupled with the slow idle speed presented by an automatic transmission load. Perhaps you can discuss this with one of their technicians and they may be able to suggest a solution. I would guess that installing a Pertronix Ignitor I may resolve your problem, and perhaps they will offer an exchange. Otherwise you may have to try selling your old electronic ignition and replacing it with either a Pertronix Ignitor I or a Crane Cams electronic ignition system. You might also consider replacing your existing distributor with a new Stinger distributor that is offered by Performance Corvairs :link: https://www.perfvair.com/stinger-ignition-distributors/. The Stinger distributor design also includes an electronic ignition system with a magnetic pulse trigger. If you do consider this upgrade you might wish to contact Seth Emerson at Performance Corvairs to discuss your intended application and to confirm with them that they have had no problems with their distributor when coupled to a Powerglide-equipped Corvair engine.

I do feel that an ignition system upgrade that includes abandoning the use of ignition points and switching to an electronic ignition is a worthwhile effort. The prices listed below are for an Pertronix Ignitor I or a Crane Cams system from Clark's Corvair Parts. This would include modifying your old distributor and retaining it on your engine. The last option is also the most expensive, but it replaces your aging distributor with a brand-new unit.

Part number C6790: MAGNETIC IGNITOR-ELECTRONIC IGNITION FITS ONLY 62-69 DISTRIBUTORS AND REQUIRES 1.5

Weight: 0 lbs 12 oz
Catalog Pages(s): 74
Price: $ 90.25


Part number C2851: CRANE CAMS ELECTRONIC IGNITION-62-69 ONLY*MUST HAVE CORVAIR ENGINE HARNESS OR COIL WITH RESISTOR

Weight: 2 lbs 0 oz
Catalog Pages(s): 74,OT,21
Price: $ 123.95


Stinger Electronic Distributor https://www.perfvair.com/stinger-ignition-distributors/

The Distributor sells for $200


If your ignition coil is a Flame Thrower II unit, it has and ultra-low 0.6 Ohm primary resistance. That particular coil will only operate with a Pertronix Ignitor II control module. It will probably also work with the Stinger distributor, but you should confirm that. If it is a conventional Pertronix Flame Thrower coil, they are available with a 1.5 or 3.0 Ohm primary resistance. If the ballast resistor wire is still present in your Corvair wiring harness, the 1.5 ohm version would be correct. If the resistor wire has been bypassed to deliver a full 12 V DC to the coil, the 3 ohm coil would be appropriate.

Obviously modifying your ignition system to incorporate a more modern electronic ignition requires a little homework. Each available system that upgrades your Corvair ignition has specific operating parameters that must be considered when fitting it to your older vehicle. The correct source voltage for the electronic module is an important consideration. Matching the electronic module with a correct ignition coil is also important. The ultrahigh voltage, high performance ignition coils are generally overkill for the Corvair engine. The compression ratio in the Corvair engine and the relatively low maximum RPM speeds do not place significant demands that would require a high secondary voltage to fire the spark plugs. The main advantage of electronic ignition is low maintenance and high reliability, that is achieved by eliminating the ignition points and condenser. Whatever your choice, it may be partially determined by the response you get from Pertronix technical support. The type of ignition coil that was installed on your Corvair may also limit your choices. Once you have gathered information from Pertronix you can make a decision on which type of system you will find is best for your Corvair and your budget. If you have any questions, please post them here.
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
my65
Posts: 155
Joined: Tue Dec 01, 2015 12:20 pm
Location: porter texas

Re: Idle at 1000 plus

Post by my65 »

Brad, thank you for this information and options. I am going to finish what I have started and if that does not correct my problems, I will try your suggestions. One other thing, my car is not an automatic but it does have ac which slows the idle when I turn it on?
Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
my65
Posts: 155
Joined: Tue Dec 01, 2015 12:20 pm
Location: porter texas

Re: Idle at 1000 plus

Post by my65 »

:tu: Well my problem was one of the primary carbs was not working at idel. Wolfe enterprises clean it up and now I am ideling at 600 rpm.
Ed ( my65 )
65 Monza Convertible
110 HP 4 Speed
63 Monza Coupe
140 HP 4 Speed
66 Corsa Coupe
140hp 4 speed
Porter, Texas
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