1997 Honda civic DX, 164 k miles, automatic. When the engine is hot and I shut the car off and try to restart within a few seconds it starts fine, if I let it sit for a min it acts flooded on startup and bucks and shakes till it regulates its rpm. only when hot. I have replaced fuel main relay, 02 sensor, pcv valve, air filter, fuel filter, thermostat, high quality distributor cap, rotor, wires and correctly gapped plugs. im stumped. spark plugs look fine, coolant is clean. coolant sensor works fine. Here Is a video of the problem.

 

Did you ever clean the IACV?

 

What is IAVC?

 

The IACV is an electric valve that the computer uses to regulate air flow into the engine when the throttle plate is closed, to keep it idling consistiently. It is mounted on the throttle body.

 

I removed throttle body and clean all parts including the IACV and also adjusted all the valves and the car still does it. Should I replace the coolant temperate sensor? Is it possible I have a leaking fuel injector?

 

replaced coolant temperate sensor and changed the 02 sensor again just in case. I think its better but not sure, to be honest doing several WOT pulls helped it a lot with sea foal fuel treatment. I also noticed fuel residue on manifold leaking from number 4 injector. going to remove injectors tomorrow and clean them and also replace seals. hope tomorrow does it!!

 

My issue was a blown head gasket