Replaced carbs but now a new problem

[Lunar_Camel]

My LH carb died on me and the car was only running no one carb. I replaced both carbs with rebuilt ones and its running, just not fine.

When I replaced the carbs, I found the LH carb did not have the vacuum plug and the RH carb was missing the power enrichment needle. Not sure how the car was running.

So now I've got two rebuilt carbs on her. Set everything according to the manual, synchronized them, timed it, and she runs a little high at idle. When I put it into gear, it shuts off.

Not sure what I'm doing wrong or overlooking. This is becoming frustrating as this seems to happen every time I do a tune up.

Anybody got any ideas?

[davemotohead]

Who did you get the rebuilt carbs from?

[Lunar_Camel]

Rebuilt them myself.

I don't think they're the problem. Once I put them on, the car was running a lot better than with the other pair.

I just can't get the idle to right spot, if not a little high. It seems like its running correct, but the car shuts of when in gear.

I tried moving the idle speed screw, but they are almost down as far as they can go.

It has to be something with the settings. If I put the screws back to factory start setting, the engine runs a little rough. I turn them 1 1/2 times clockwise, it runs fine at idle. I just can't keep it running in gear.

[Lunar_Camel]

So thinking that maybe one of the carbs is not working right (or both for that matter), I switched them. The L is now on the R and vice versa. Still having the same problem. The engine shuts off when it goes in gear.

Since this is my daily driver, I'm fighting time to get her fixed. Already took one day off of work to work on her.

[bbodie52]

With a Powerglide automatic transmission-based Corvair, the idle speed is supposed to be set with the transmission in DRIVE — not NEUTRAL. See NOTE 4 regarding engine idle speed in the chart below.

1965 Corvair Chassis Shop Manual Tune-up Chart

If you set the correct idle speed in NEUTRAL, as described for a manual transmission-based engine, the engine will likely bog down and stall when shifted to DRIVE and loaded by the torque converter. The idle speed must be increased slightly to compensate for the load placed on the engine by the fluid coupling associated with the automatic transmission.

The initial mechanical setting of the idle speed screws of 1½ turns down on each side from initial contact is only a starting point. A vacuum gauge (like the Uni-Syn gauge) will accurately measure air flow through each carburetor throat, to permit more-precise synchronization of the two primary carburetors.

In addition, the final idle speed will have to be increased slightly, as described in the tune-up chart, to settle on a final idle speed in DRIVE that reliably permits engine idle when the vehicle is stopped.

REMINDER — Engine timing will affect idle speed, so it is important to properly set the engine timing before setting the final idle speed. Ensure the vacuum advance hose is disconnected and the idle is slow enough to prevent the centrifugal advance from engaging. As you can see in the distributor chart below, the centrifugal advance mechanism in most late model normally aspirated Corvairs begins to affect timing at about 800-900 RPM. The base timing setting, when checked with a timing light, must be checked with the engine idling at a speed below 800 RPM, and with the vacuum advance hose temporarily disconnected and plugged.

[Lunar_Camel]

I think that's what I'm always forgetting. No matter how many times I've tuned her up, its always when I put her into gear I have problems.

I need to start remembering to set the idle speed in drive. Maybe I should write it down.

[Lunar_Camel]

So I went back, started her up and tried again. According to my dwell meter, she's at 1700 RPM at idle. According to the manual, with factory settings, she should be around 500 - 850 range and around 1100 RPM at high idle. The timing is set at 12.

So why is she at 1700 RPM? And how do I get her lower without the car stalling? I am at a total lost.

Anyone know of a mechanic who makes housecalls?

[davemotohead]

Where are you located in LA? Have you ever rebuilt a carb before or is this your first try at it? you are not mistaken the Idle air adjustment screws for the Idle screws are you? Are you sure you have all the vac lines connected and any Vac leaks sealed up? Did you check the Vac line on the trans? it can easily be disconnected when playing in the engine compartment!

[66vairguy]

1700 RPM is WAY TOO HIGH for setting the timing accurately since the distributor is mechanically advancing at that RPM. Of course it could just be your meter is WRONG. If you put a Corvair in Drive at 1,700RPM it would probably chirp the tires and jump!

Tuning a car requires skill that comes from experience and practice. Since you need this car for daily transportation it's probably best to just take it to a California Corvairs and let Jeff sort it out. Davemotohead is also a good troubleshooter and repair guy, but he is up in Lancaster.

BTW SCC in L.A. asked at the last meeting if anyone was interested in attending a tune-up session some weekend at the parking lot of a business that one member owns. There was little interest. It seems most new members are no longer interested in working on there own cars. Of course that's good for the Corvair mechanics!!

[Lunar_Camel]

I'm in Highland Park, between Glendale and Pasadena.

I've rebuilt carbs before without any problems using Clarks deluxe kit (even had one of the carbs working without the power enrichment needle without knowing it) and Bob Helt's book "How to Identify and Rebuild Corvair Rochester Carburetors".

I've checked all the vacuum tubes and everything is in working order. Most, if not all of the tubes are new. I'm getting good suction on both carbs. The line on the trans is brand new as I just replaced it (that was another issue).

I'm pretty sure I've been turning the right screws. The idle air adjustment screws are at the base of the carb. The idle screws are midway up the carb and engage the throttle plate. A question about that: I've noticed that when you adjust the screw before putting them on the screw barely touches the plate. But when they are on the car, the screws don't touch at all? Could this be the problem and if it is what's causing it?

@66vairguy: I would totally be interested in tune-up session and someone teach me how to do a tune-up. I asked once at California Corvairs and they said they couldn't because their insurance doesn't cover anyone inside their repair bays.

I always run into this problem after a major tune-up. After a few days of playing with it, I usually get to where its supposed to be. But it would be nice to do it in one go. I've had to rent a car to get to work till I figure it out.

[davemotohead]

Disconnect the throttle pivot lever at the cross shaft, the lever coming from the gas pedal to the cross shaft in the engine bay, the swivel that the return spring goes to, adjust your idle and balance the carbs with this disconnected, then once all is well adjust the swivel on that link to where it is not holding the carbs open at idle.

[Lunar_Camel]

Since everything I did still resulted in the same problem, I took it to Jeff at California Corvair's.

Unfortunately, the engine is blown with zero compression in two of the cylinders.

So I'm selling it to him to use whatever parts he can use.

This will probably be my last post since I'll be out of the Corvair circuit.

Thank you to everyone who has helped in any way, big or small.

It was fun while it lasted.