Engine shudder
 

I'm finding that my engine will shudder a little bit while warming up. Usually around 1000k RPMS as its idling down. I can hear, and watch the engine shudder. I hope I'm not losing compression, that would bite. My engine will also shudder, from time to time, while its idling normally. I'm driving an 85 GSLSE with a 13b.

Any Ideas? Thanks!

M.

mine runs ruff and shutters when it is warming up too. no idea why

Don't all FB's do that? My 12A does it less now that I've removed all the emission gear and vacuum advance, and if I really get the idle mixture adjusted perfect it hardly does it at all.

Certainly nothing to worry about. Rather common, as SilverRocket mentioned. Still, a few ideas:
If they are due, you might want to replace the usual items: plugs, wires, rotor, cap, air filter. Tighten the intake air duct and clean the throttle body and throttle plates. Clean and oil the throttle linkage. Adjust the TPS (engine warm).
If that doesn't do it, remove and clean the BAC and ACV. After that you could remove and clean the injectors. That would be a good time to replace all of the vacuum hoses.
Or maybe the stumble isn't so bad after all? :)

-John.