My brother in-law's 96 prelude was oil starved. We swapped in a jdm h23. We had to wire the obdI motor to work with the obdII ecu (block vs distributor sensors -- this is an auto btw). The motor runs awesome, pulls like a champ, but after it warms up and heat soaks a bit, we get random missfire codes. It can be under full load, or just crusing at 40kpa on the highway -- and it doesn't feel like it's missing most of the time, but I think we 'felt' it once. In other words, it's a frustratingly hard problem to troubleshoot.

The ecu is not throwing any codes other than the p1300 p0300 and various p030x codes. The thing is running new plugs, we've swapped wires, ignitors + coil, cap and rotor, checked and double checked the wiring, checked timing (cam teeth and base timing with a gun), ensured the im dual runner vac motor is indeed operating, datalogged (via obdII scan tool) and watched to ensure the o2 voltage was showing lean when it should, rich when it should (like under full load), that the rest of the sensors were reading values that were very sane (including ignition & map values at cruise, load, and idle). I've done a compression test, leak down, and valve adjustment.

About the only thing we haven't done is to swap actual distributors -- and that is our planned next step.

I really need ideas here -- it's like there's a ghost in the machine. Please gimme some ideas for the next time I get to work on this car -- it's driving me nuts!

Wayne