Rep Power: 0

I've went thru and seached the forums on this topic, but haven't been able to find a cure for my problem. I've got a 1997 Civic Hatch DX that I just replaced the stock 1.6L engine with another stock 1.6L engine. After I got everything done I fired it up and it started and seemed to run really smooth. Once the engine had warmed up it began surging up & down at idle. It would go from ~800 to 1500 RPM over and over again. When I gave it some gas it smoothed out and the problem went away. I don't notice it when I am driving, just in park while the car is idling??? Does anyone have any ideas? I pulled the IAC sensor off and let it run without it and it seemed to steady for a while, but then the surging came back.

Thanks,
Chad

 
Rep Power: 247

Did you mix up the IACV and TPS sensor plugs? I think they both have the same plugs that are commonly switched and that can cause this problem.

 
Rep Power: 0

Thanks, I was confused about those plugs at first, but the IACV plug has longer wires so I figured it went to the IACV instead of the TPS. I spent quite a while last night bleeding the coolant system out and could not get it to idle right even with the heater on full blast. I pulled it out of the garage and onto the sloped driveway and that seemed to get the bubbles out of where they weren't supposed to be.
Know of where I can find the rubber piece that goes inside my window track? Mine is missing and the window doesn't go all the way up without it.

Chad

 
Rep Power: 0

i dunno i'd say spray some cleaner in the throttle body but being that it was right after the engine swap it's probably something more complex.

 
Rep Power: 0

I've got the idle surge solved. I began by bleeding the system of air with the heater on full blast but it still seemed to do it so I let the car idle on an incline facing both directions and that was enough to get the air out of the system.

Thanks,