Rep Power: 0

title simply states the problem. I previously thought that it was a leak that i had in the exhaust. I fixed that, surge still there. Then thought it had to do with my failing alternator. replaced that this weekend and the surge is still there.

It happens when ever it feels like doing it, its not consistent and triggers no check engine light. the only thing that i can say that is associated with it is electrical load. its most pronounced at night after i drive with my lights, heat and radio on. as i turn my heat and lights off while pulling into a parking spot (coasting in neutral w/ engine idling) the surge will begin immediately after killing the lights and/or heat.

It will occasionally surge when i'm turning on the off ramp and coasting in neutral. I can make it stop by turning the heater on a higher setting and adding the rear defroster (increasing electrical load)

Any ideas?

94 civic dx
manual trans
208xxx

 
Rep Power: 253

Thats so weird, check your ground wires to start. Especially the ones going to your alternator and your battery, as well as engine and tranny grounds.

 
Rep Power: 0

engine/transmission grounds checked... where is the alternator ground?

 
Rep Power: 0

I'm going to clean out the iacv today. is this a waste of time trying to fix the idle issue? its probably well over due anyway so i'm going to clean it regardless, but is there something else i can do first to fix the idle surge.

iacv and throttle body cleaned. they werent as dirty as i expected for 208xxx. Surge is still there though. I also checked the vacuum lines, none appear to be cracked. I want to just replace 1 at a time and drive for a day or to until i either stumble on the one that fixes the problem, or again find nothing. which one should i start with? should i just close my eyes and pull a hose off?

1 detail i forgot to mention: i dont recall it ever happening when the engine is cold.

 
Rep Power: 0

This started happening to me about a month before my CEL came on... It was the O2 sensor. I changed that and the problem went away.

 
Rep Power: 253

Yea it kinda does sound like an O2 sensor.. if you have a chiltons boot and a volt meter you can check to see if they are good..