L24 Mikunis Rev/idle problem

[mistah mofro]

Got the car to idle, but idles super duper rough and completely bogs out when I apply throttle. If I hold the throttle down a bit and turn the dizzy clockwise (adv?) it slowly begins to pick up revs but dies out once I let off. I have an e12-80 dizzy along with a entirely new ez wire harness. There's 12 volts at the coil, I took the carbs to make sure their even spraying fuel which they were. If I remember correctly my spark was orange-ish if that helps at all.

 

Just wanna drive my car already.

Edited April 23, 2013 by mistah mofro

[inline6]

Which Mikuni's, 40's or 44's?  What is the history on them?  New... old... bought used, unknown history?    

 

Do you have a timing light, and can you see what the timing is set at?  If it was me, I'd look up the timing value to use for that distributor (use the value for whichever datsun it came off of - 280zx? I just don't know which car it came from) and set it at that.  

 

And, I'd check and reset the carb float levels.  Typically, you can remove the tops of the carburetors without ruining the gaskets.  Then go about setting the float heights - the distance between the  top surface of the floats (two per carb) and the underside of the carb cover.  Note, that each one of them needs to be checked.  If one is lower than the other, you have to bend them,like grabbing a wish bone of a chicken and moving one up and the other down... until they are nice and level compared to each other.  Then set the distance between the tops of the floats and the bottom of the cover at 12.0 to 12.5 mm.  I cut a thin strip of metal and grind/sand to the precise length.  Then hold that with needle nose pliers between the float and the chamber to check/adjust the height.  Typically you hold the carb cover at 90 degrees compared to the floor when checking, so that the floats don't have gravity pulling them down away from the needle valve or pushing hard against the needle valve.  You want just enough pressure from the float arm against the needle valve to depress the pin it contacts, but not to open the valve itself (it has a noticeable stopping point, right before the valve itself opens).  

 

There are a couple of ways to adjust the heights, but I prefer to just bend the tab on the float arm... where it contacts the needle valve.  It only needs very slight movement there to effect the needle valve closing point.

 

Are you familiar with the jets in the Mikuni's?  Do you have other sizes on hand?