Hi, I have a 92 Honda civic dx with a automatic tranny. My engine blow up so I decide to do a engine and tranny swap. I use a 97 civic engine d16y8 with 5 speed tranny. So I did the swap but now I have idle problem. The idle jump up and down from 1000 rpm to 2000 rpm. Let me explain all I did to do this swap. Before I put the engine I replace a lot of parts. Here the list for the parts I replace. Valve cover gasket Valve stem seals Head gasket Oil pan gasket Cam shaft seal Crank shaft seal Rear main seal Timing belt Water pump Tensioner belt Intake manifold gasket Exhaust manifold gasket Transmission seals Cutch kit Flywheel Clutch slave cylinder Sparkplug & wires Distributor cap & rotor Pcv valve Thermostat Radiator & cap I took everything a part and took my time to put it back together. I recheck everything. I used my original engine harness obd1 and use a p28 ecu. I read a post on another forum about how to put a d16y8 intake manifold into a d16z6 so I use that info to make my y8 manifold work with my obd1 setup. The only thing is that I didnâ€™t have the z6 throttle body so I use the one from my old engine 1.5 non vtec and I donâ€™t now if that my idle problems because the map sensor is not mounted on top of the TB is in the fire wall. If you look closer the intake manifold you could see where I mount the purge control solenoid on back of the manifold and the IAT sensor on the side. Another thing is that I still using the IACV from the y8 engine and not sure if the one from the z6 will fix my idle problem. Also the TB and FITV are from my old 1.5 engine. Now about the wire harness everything was plug and play. I only did the wire for the vtec and was only from the vtec valve to the connector next to the battery, from there to the ecu was already rewire from factory. So I donâ€™t think there a problem is with the wires. Here are a few thing that I already check. Timing belt is right on Bleed radiator Clean the IACV Clean the FITV Bypass the coolant hose Check for vacum leaks Check the sparkplugs and gap I really donâ€™t now what to do. This idle problem is making me crazy. Other then that the car run really good. I took it around the block and has a lot of power and that intake sound real loud when that vtec engage. All I need to do is fix that idle problem so if somebody could help me please.