1997 Honda Accord VTEC with 2000 Honda Accord VTEC p0304
I just swapped a 2000 honda accord engine into a 1997 Honda accord. The engine that was originally in the car was an f22b1: 2156cc 8.8 to 1 compression ratio 85mm bore 95mm stroke The engine that swapped into the car is an f23a1: 2254cc 9.3 to 1 compression ratio 86mm bore 97mm stroke I am running this swap on the factory f22b1 computer, with the factory f22b1 intake manifold, sensors, injectors, wire harness etc. I moved all the f22b1 parts that were originally in the car and only switched the engine block which has a bigger bore and stroke and higher compression. The car starts up right away and idles. It is throwing a check engine light. I am getting code 74 when sticking the paper clip into the blue harness plug under the glove box. (7 long puase blinks and 4 short pause blinks) I looked this up and it is the same as obdII code p0304 (misfire deteced in #4 cylinder) I can hear the cylinder missfiring at idle. It is making a knocking sound. I have tried replacing the #4 fuel injector with the one from cylinder #1. This did nothing. -the code did not change to p0301 so I can assume the injector is ok I put new plugs and wires in the car. I tried pulling off the #4 spark plug wire while the motor was running and the engine hesitated alot (so I know #4 plug is firing) I suspected a vacuum leak because when I blipp the gas at idle, the idle falls and the motor almost shuts off and then it begins to idle again. I checked the egr gasket, intake manifold gasket, throttle body gasket, and all appear to be OK. EGR seems to be working fine. I can not find any holes in any vacuum lines. This is driving me crazy. I put 93 octane gas in the car because the motor I put in has a higher compression ratio, and a bottle of fuel injector cleaner. Could the slightly larger bore and stroke and slightly higher compression ratio be causing the missfires? If so, then why only on cylinder #4? Could the p0304 code be for random cylinder missfires and not for cylinder #4? I read that faulty catalytic converter and o2 sensors can throw this code. Why p0304 though (#4 cylinder only) and not p0300 (random cylinder missfire) if the cat or 02 is bad? I can hear a noise coming from what sounds to me like #4 I did a compression test and all 4 cylinders are reading between 140 and 150 I checked the valve lash at TDC for all four cylinders. There arn't any valves stuck open. What else can I do to fix this problem? Could it be the ECU and engine missmatch causing the problem. I assumed the ECU could compensate for such minor changes from F22b1 to F23a1
Well, if you kept the original PCM for the new engine, that could be your problem. I don't know for sure, but I'd check all the cylinders for a misfire. Ive had it happen that the scanner tells me cylinder 1 is misfiring but it was actually another. So go back and double check ignition on all the cylinders and swap all the inj. next and see if the code changes. If it changes when moving all the injectors around, then you know the PCM is misidentifying a cylinder.