87 integra "misses" at rpm

i have this 87 integra that i bought a couple weeks ago, but didnt drive it much. Now if i drive it for more than 15 min, it starts to miss if i try to go beyond 5000 rpm. So i think its having problems after it gets warmed up. Has anybody else had/fixed this?

try new spark plugs wires. cheap trial and error, it could be the problem or it may not be, but if it fixes it you only spent 20 bucks.

You just bought it and its an older car so its a good chance the previous owner didn't tune it up before he sold it obviously. So like I said wires, or even plugs or rotor. If you can't give it a full tune up try the wires and check the plugs first.

i replaced the wires, plugs, distrubitor cap and rotor...still no help. I was wondering, the guy that had it before me put a intake on it. and the cone filter sits almost behind the battery, could it be getting too hot under the hood where the filter is? it seems to work better when on the freeway.