i just bought a 1985 civic crx 5 speed about a week ago. before i bought it, it looked like it ran n drove good for a 25yr old crx. i put it on the road yesterday when i went to drive it for the first time it being one the road, " the idol is being stubborn it holds steady at about 850rpms sometimes, when i go to try to hold the gas peddle at any rpm it doesn't hold n the rpms drops." i thought it would have be the fuel filter but i changed it n i found out i was wrong, i cleaned the carburetor its getting gas fine, i dont know what to do next besides map sensor i want to try to diagnose this before i spend 250 on a map sensor im just trying to figure out how i can get this beast running strong n spend the least amount of money i can so i can save money up for a swap. any lil bit of information helps n will be appreciated, n im willing to learn.
If you have a carb, you won't have a MAP sensor (that was only for the fuel injected Si models). The carb base gasket on these engines typically develops cracks or you could have a cracked vacuum hose.
There are two fuel filters- one up by the carb and one under the car just in front of the tank.