It Just Won't Run!

Well, it is actually a Classic - it’s a 1965 turbo-charged Corvair. It has been my toy and has run great until last year. Bad gas (hadn’t driven enough to buy any gas for a few summers) was the problem. Added super injector cleaner and it started, but too late in the season to insure, license, drive. Added Stabil to tank. This spring, would not start. Disassembled & manually cleaned film/coating from carb & fuel pump. New accelerator pump. Now it starts, but will not run below 1000 RPM. Readjusted carb internals (float level/drop, meter rod height, etc) to factory specs, same with ignition. Still no. Timing light on coil wire shows ignition is good all the way as engine quits. Carb has fuel in bowl. I am stumped. Any ideas?

You probably have to clean/rebuild the carb.

Once gas turns bad, it can restrict many of the ports in the carb. One of them being idle circuit.

Tester

Your “fast idle” cam could be sticking as well as your accelerator. Have you disconnected the accelerator or checked the fast idle cam? You could also have a vacuum leak which will keep your idle high.

Just to clarify this, are you saying the gas that is in there now is what was in there 2 years ago? If so, it all needs to come out. Cleaners and Sta-Bil will not cure an aged gasoline problem.

If the engine is running well at elevated RPMs and not at idle or just off-idle then you likely have a vacuum leak problem or a problem in the carburetor idle circuits.
With the latter this usually involves a rebuild and that means soaking the diassembled carburetor parts in carburetor solvent (or acid as mechanics often refer to it) followed by washing out thoroughly with water and then blowing out all passages with compressed air.

Make sure you use new gaskets and check for air leaks if you take it apart again.

Thanks for your reply. I have cleaned and rebuilt the carb. I did not use chemicals to do this, so maybe the idle circuits are still fouled. I will now try to clean those circuits. Is there a chemical or solution to use for this?

I believe I have checked the linkage & cam. However, your comment about a possible vacuum leak sounds possible. I now understand the carb mounting is a little prone to abuse of a particular gasket if one of the mounting nuts is over-tightened. I will proceed to check this. Thanks for your reply.

Thanks for your help. This episode has taken so much time now that all that old gas is gone. If fact, one of the problems during these efforts was that there was no fuel in the tank. (Talk about embarrassing…!) So from trying to run on empty, I have now added 3 gallons of fresh gas. Your comments about vacuum leak and idle circuit support an earlier reply above. I now believe these issues might be involved. I plan to try to resolve them.
BTW, is that solvent/“acid” something I can find and use at home? Or do I take my carb to a shop for this?

Thanks. As noted in some of my replies above, these issues might be involved - especially since I have had that carb off & apart sooo many times now. I will proceed to try to resolve them.

Okay, I have considered all the replies. I ordered a new gasket btwn carb & turbo (where I removed carb to clean it). I have soaked the disassembled carb parts in commercial cleaner and rinsed - they are drying overnight. When gasket arrives, I will try again. Hope all this solves the issue. Will let you know results later…