Did it continue to run at a full idle, or was it dieseling? If dieseling, is mentioned, carbon may be a culprit. However,I have also observed that incorrect idle speed along with insufficient ignition timing is also a common cause of this. Were you doing anything, or have you done anything recently that would result in increased idle speed and decrease initial timing settings?
It idled how it regularly does which is really high. And the only thing I've done was have someone clean/rebuild the carburetor. I'm like 99% sure its not tuned
I want to be careful to say this is not the only reason a car might diesel - I am not an expert, but have dealt with this, so this is just based on my own experience.
You may want to try looking into proper idle and timing settings. Your engine specs (ie, camshaft duration, compression, etc) can play a role here. Fora mildly built engine, I try to get into the 600-800 RPM range and anywhere from 14 to 20 degrees initial timing - engine specs will influence this, so knowing what you have under the hood is helpful.
I had dieseling issues with my 79 corvette after building a stroker. I had 1025:1 compression and the cam was about 230+ degrees @.050. Once I got it to idle at 800 RPM and set the timing to about 20 degrees initial, that went away. No pinging at cruise, the engine seems to like it.
IF you go this route, only make small changes and check the result. If possible, try test drives not just start it up. I would reset your idle speed, then go cautiously with timing, especially with the timing. Start conservative with the timing, and just bump it up maybe 2 degrees at a time until the dieseling stops. Pay attention to total timing at around 3000 RPM, you probably don't want to go more than 36-38 (not counting if you run a vacuum advance). More efficient heads can lower this total advance, so these are things you will want to make sure you know about your engine.
If you have a really aggressive cam, you will probably need more timing to get it to idle at lower speeds. If this is the case, this can also help low-speed drive-ability.
Then make sure you don't experience any detonation (pinging) at cruise. You may find it helpful to incrementally drop idle speed as you advance timing, but I prefer to get one where you want it and try to tune the other till you solve the problem.
Just one approach to consider - if you are not sure what you have under the hood, make sure you do a bit of research first.