Hi have 93 civic 1.6 that had low idle and at start out wants to bog down to the point of stalling. Oddly above 2200 rpm it is better. Unfortunately No check engine light.
What has been done: new fuel filter, new timing belt, water pump, timing has been checked, cooling system has been checked, no cat blockage, cylinder compression test is within Honda spec, scoped cylinders, triple checked TDC marks, could not find vacuum leak (constantly looking), no horrible valve noise. As this does not appear to be consistent I am not sure were to look next. For example, it idles great when I first start it up and get it to temperature, so it does not appear to be injector related.