[Andrew240Z]

2.8L P79 head, with roundtop 4-bolt carbs, the front three cylinders are NOT firing, I know because I can unplug the first three plug wires, and nothing happens. I know this must be an SU problem but I dont know where to start looking!! please help!
-andrew
73 240z
82 zx

 

[johnh240]

Take the top off the fuel bowl and see if there is gas in there. May just be a stuck or misadjusted float. Also make sure that fuel is flowing through the line to the front carb. Disconnect it and run fuel pump (electric? or mechanical?) by either turning on the key or cranking the engine. Put the line in a container and make sure fuel pumps out of the line. When you say the front three plugs are not firing, do you mean there is no spark or that disconnecting them makes no difference?

 

[Andrew240Z]

If I take the plugs out, and sit them on the valve cover, they fire, so I'm assuming that if they are firing outside of the engine, that they are also firing when they are installed.