The engine was built recently and everything worked fine until i boost it to 14psi, the car was burning rich base on my plx wideband. The idle is now rough.

I have 550 fuel injectors. Walbro 255 fuel pump, s300, vitara pistons, eagle rods, garette t3/t4 50 trim on a d16z6 eg civic.

Here is my troubleshooting steps. I unplugged each spark plug wire at a time and only notice cyclinder 3 does not make a difference when I unplugged it. I check the compression cyl 1=148 2=146 3=145 4=150. I performed a resistance test on the wire and everything is within specs. I even checked to see if there was spark coming from every cable by having the spark plug in the wire and close to ground. I pulled the valve cover off and check the timing just to make sure the timing belt did not jump. last I pulled the oil pan off to make sure I didn't spun a bearing. Nothing is wrong.

What can the problem be? Yesterday I went and replace the sparkplug wires and no difference. Any help will be great.

Today i changed the sparkplugs, rotor, and cap which didn't make a difference. I use the dizzy from my other 95 civic and didn't make a difference. I pull the fuel rail and injectors and made sure that the injectors are working and it is pulsing. I also check cylinder 3 dc voltage and it is within specs. I also checked the iacv and cleaned it.

The only clue that is worth anything for me is the cylinder 3 sparkplug have gas on it when I pull it out in comparison to the other plugs which are dry.

 

Did you do a leak down test?

and is it tuned or just running the base map?

which map sensor are you using?

 

i am running a base map and using the hondata 4bar map sensor.

 

Are you sure theirs a piston in cylinder 3?

 

Yes there is a piston in the cylinder. I'd pull the oil pan off already and there is compression in that cylinder. I am going to pull the head out this weekend to see.

 

Someone made a suggestion in turbod16.com and it made a difference.

In the smanger under parameters and fuel trim if I put the 3rd cylinder 75% from 0% fuel it runs smooth. But if I rev it, it make a popping sound.

What next? Guys help me please we are getting close to the symptoms.

 

Bad injector?

 

swap the number 3 injector to another cylinder and see if the problem moves with it.