bigirish727

Hey i'm new to hondas(and cars in general, trying to learn). I have a 93 ex with d16z6 vtec engine that i just got. The engine in it is rebuilt at 85,000 miles.
The problem: When i start it the engine revs from about 1500 to 2100 rpms consistently. at first and 2nd gear its really jerkish and it kinda boggs out. But after it warms up its not as bad and sometimes quits all together. When i turn the AC on it stops also.

Only mods on it are cold air intake and header(if that helps any), the prev owner cut the exhaust after the cat.

I dont think its the idle air control valve, I'm leaning more toward a tps problem??? Which would suck bc i'd prob have to replace the throttle body. But like i said im new to cars and since the pipe is cut its super loud and annoying and sounds like the car is going to blow up lol, if someone could help me identify what this problem is and an easy/cheapest way to fix it that would be greatly appreciated. Thank you

Running Riot

without further information that sounds exactly like a IAC. is it auto or 5 spd?

the iac will cause that bump up and down from air in the coolant system believe it or not. TPS sensor can cause it too, google "civic tps sensor check" and go from there. Also google, "how to check obd2 codes civic" and see what codes you are throwing. If the MIL isn't flashing at you, there is no bulb in it. put one in. obviously. give those a try and holler back.