I have a 99 civic lx that we've been trying to fix for a while now. It'll crank and run til it warms up then it shuts off and won't start again til it cools down. The longer I let it cool, the longer it runs the next time. I've read a number of posts on here as well as other places on the web, that were about the same issue and I've checked all sorts of things as a result. The fuel pump is working, the plugs all have spark. It does throw a code p1399, which is a misfire somewhere. I bought a compression gauge and checked last night and it is losing compression when it warms up. Should I give up on this car? Please help!

 

What are you compression numbers?