Shootin' carbon out the tail pipe!
 

My 83 GSL SE 12A has been parked all winter, so I decided to start her up today seeing as we finally got some decent weather. I had it plugged in for about 2 or 3 months and it started up just fine. (I checked all fluid levels before starting and everything was normal) After starting I opened the hood and the engine sounded like it was making "clacking" noises, but they weren't too bad. So I let her warm up almost till choke kick off, and the noises went away. I revved her up to 5000 RPM, and on the rev down just after I let go of the pedal there was a huge backfire and it kicked probably about 1/4 - 1/2 a cup of carbon out the tail pipe. I did it a few more times to get some more out, and it finally settled down after 4 or 5 backfires. I know my car needs a tune up, but I just wanted to start it because it has been so long (for me, and the car... but mostly just me!) I just can't wait till all this snow goes away so I can get her all tuned up, and put her back out onto the streets. I have done the "de-carbonization trick" because it wouldn't run last year. It brought her back to life and I did it again just before putting her into storage. Anyway I was just wondering if this is normal? Should there be a considerate amount of carbon kicked out after sitting for a while? I don't remember there being this much carbon kicked out last time I did the d.c.t. Your help is greatly appreciated.

It more than likely came from the carbon caked on the inside of your exhaust. If you really had 1/4-1/2 cup of carbon coming from your engine, you'd have serious problems i would think.

I forgot to add that my engine has 250K, I know it's alot which could explain the high carbon content. And seeing as I've already brought it back from the dead once, how long do you think till I'll need a rebuild? Is there anything else I can do to prolong the life of my 7? With that much carbon being caked into my exhaust would it be better to get a new system or is there a way to clean it out somehow? The car came with an aftermarket header, not sure which brand.

GSL-SE 12A? I don't believe they made hat

And they didnt have Se's in 83 so im assuming he meant 83 GSL with the 12A

The backfires loosened the carbon buildup in the exhaust pipes. If it continues to run normally, keep driving it. With the mileage, I would drive it till it died and expect to replace the rotor housings and maybe all 4 bearings, along with a full rebuild kit.