I have a b18a that I did an water pump on a few weeks ago and now it doesn't run so well. Also, it is know consuming a lot of fuel. I double checked the TDC timing mark on the crank to the mark on the oil pump and lined up the cam gears markings and arrow pointing up. The cam gears are a couple of hairs off (1/16-2/16in) but that shouldn't effect it that much, would it? I also check the voltage for the map sensor and it turn out fine and bought an new o2 sensor, but the car still hesitate when accelerating and consuming a lot of fuel. Checked all the vacuum hoses for cracks and leaks. I have no other ideas. What can be the cause of this?

 

Your timing may have slipped, cam gears should align perfect not 1/16 to 2/16 off! thats throwing up a big flag unless this motor is decked and or milled to throw off the timing, redo the timing belt and double check your timing marks and make sure theres no slack in the timing belt. Check the ECU codes and address them if theres any codes cause your running rich then reset the ECU and test.

 

^ Agreed get the timing fixed first and then go from there.

 

Also, check out your ect sensor.

 

As stated, fix your timing - the marks should all line up PERFECTLY.If that doesn't resolve the issue, let us kno and we'll proceed from there.