As the title states; my integra misfires as soon as it reaches operating temp. Its to the point where it can't be driven. I've read numerous threads on numerous honda chassis with the same issue and different culprits. The difference in my case is the fact that all I did was swap shells.b20b swap was in a 94 LS shell (usdm). LS was daily driven without any issues for a year( CEL for 02 sesnor). Had a cleaner 94 GS-R shell with JDM front that I wanted to put to use.

I literally took the b20b out of the LS and plugged it into the GS-R. Should have been plug and play, but of fkn course not. Any suggestions? I'm clueless. Distributor is a few months old, checked injectors with ear to flat head ( they all seem to open/close), spark and idle are fine when I first turn the car on, but then 2/3 start missing and lose spark when warm, there should be no way timing jumped from taking the swap from one car to the other. Dizzy never moved. My only CEL Is for the same 02 code I had in the LS.. Doesn't make sense that in 3 hrs a swap goes from no issues for a year in one shell to issues instantly in a another.

 

Put a o2 sensor get the code cleared. Double check all the plugs are in the correct plugs and same with the injector plugs. Test the ECT sensor and make sure its working to spec, It could be bad and soon as the engine warms up it no longer works right causing drivability issues. Double check ignition timing with a timing light.