Is a bad cylinder the end of an engine? on 1990 Honda Accord

One of my cylinder compressions is only 30 psi. I'm wondering if this is something worth repairing or if that's the end of the engine. She runs really rough, I have to put her in neutral and rev the engine just to keep it going at a stoplight and she smokes bad when she starts up. The engine makes a sort of clicking sound and shakes. Makes it hard to sell even for a really low price!

Asked by for the 1990 Honda Accord
have a compression test done wet and dry to determine if its upper or lower part of eng that is failing. then decide based on est
2 more answers , 2 more comments
First question to ask is , how much do I like this car? Second is what shape is it in overall? Then get it diagnosed.It can be anything from poor valve adjustment to bad rings and many things in between.If the correct diagnosis can be made in an hour or so , would the car be worth paying a REPUTABLE shop in your area to diagnose it?Who did the compression test , and which cylinder is it?
Thanks for the reply, a friends mechanic dad did the test. I can't remember which cylinder it is unfortunately. Honestly I don't want the car anymore, I'm trying to sell it for 800 but I don't want to be asking an unfair price. Nice to know it could be a number of issues. I should get it checked out at a shop, at least then I would be able to tell the buyer what is really wrong with it. I had put a lot of work into it not realizing the engine was the issue. I had replaced the valve cover seal and valve rings - I could be wrong on the name, but I replaced the O rings that come with the valve seal, is that what you were referring to when you said bad rings? Sorry about the vocabulary, I'm a pretty new to mechanics.
The smoking on start-up could be valve stem seals,still an expensive fix-relative to the cars value.Head-gasket is another possbility as stated in answer #3 , although on those engines it often is between two cylinders giving you low compression in two adjacent cylinders.The 'sort of clicking sound' is hard to determine on-line as everyones perception of sound is different.No matter said you don't want the car....there is your answer. Good luck.
You don't have a bad cylinder, you have a blown head gasket. Usually you will see white smoke which is an indication of water/antifreeze leaking between cylinders. Everybody believe's they have a bad motor when this happens. If you happen to know of a good shade tree mechanic, get a head gasket set at your local auto parts and spend the better part of a day. Make sure you have your head resurfaced. Blown gaskets cause a world of problems but it's a lot of fun repairing. Goodluck