Engine Performance problem
1996 Honda Accord 4 cyl Front Wheel Drive Manual 112k miles

I had a bad cylinder in my old engine and it was obviously running extremely rough so i purchased a used engine with 112k miles on it from a certified wrecker. Had a local shop install the engine, swapping all components except for coil and injectors.

After R&R new engine starts and idles rough but has even less power than my previous engine did on 3 cylinders. All cylinders in new engine have over 160 lbs and has spark and fuel. Timing is checked. Computer says the O2 sensors are out on both manifold and catalytic conv. and that it is running too lean.

When driving it feels like the engine is fighting itself for power... revs, but has no increase in torque or acceleration..
Had catalytic converter checked and even went as far as to drop the entire exhaust to see if that was restricting it but no change in power.

Could this be a fuel pump issue? Throttle positioning sensor?
Where should we start? I'm at a loss...

Hi there,

I would be re checking the valve timing, ignition timing, scanning for any set fault codes, checking for vacuum leaks, checking valve clearances, start there.

Mark (mhpautos)

thanks.. it starts on a dime still so i think i can rule out ignition timing.. but i'll be checking for vacuum leaks today and also trying to find a fuel pressure gauge to see if the fuel pump somehow isn't functioning properly..