1950-1966 [Subscribe to Daily Digest] |
First, check the ignition system before you do anything else. Flames shooting out of the carb can be a symptom of the timing being off, and if it's off you'll never get the carburetion right. Don't stop with timing, though, also check the firing order and the general health of the points, coil, plug wires, rotor, cap, etc. This is all just to save you headaches of troubleshooting one area when part of the problem may be in a different area.
Okay, let's assume the ignition stuff is all OK and that you've strictly got carb/fuel problems. I've never used a Facet pump, but it sounds like a good guess that you're trying to put too much pressure past the needle valve, causing extra fuel to flood into the carb. This would explain why it runs OK at higher RPMs (where the engine can use up the extra fuel) and then goes over-rich after idling a few seconds (it takes that long for the extra fuel to accumulate.)
Is there any way you can disconnect the Facet and go back to the original mechanical pump (I assume you removed or bypassed this) to isolate the potential problem area? The original mechanical pump is supposed to have a max pressure of 3.4-4.3 psi at 4000 rpm, so in theory your pump should be within that spec -- but who knows, maybe it's stronger than rated.
If the pump isn't the problem, you've got to look at the possibility of something going wrong with your carb rebuild. Normally when adjusting the idle mixture screw doesn't do anything, it's a sign of an air leak somewhere. The idle mixture screw shouldn't have any effect at anything EXCEPT idle, so there's no point in trying to adjust it for best running at higher RPMs; the carburetor has a separate circuit to handle high RPM running.
If your carb is working correctly, there shouldn't be much to getting at least a roughly correct idle adjustment: set the idle stop screw so the engine is idling as slow as it will run smoothly, adjust the mix screw until you've got the smoothest idle, then turn the idle mix screw inward until the idle speed drops off just enough that you can hear it. That should put you pretty close to "lean best idle." Then reset the idle stop screw so the engine idles at 1000 rpm or just below that. If you can't get a good setting following this procedure, then you've got problems in the carb or elsewhere. Good luck and have fun!
posted by 68.227.170...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
