Tuning Carbs 1977 260z

[1200 Koozer]

Hi guys. My 260z seems to be running far too rich. It has the flat top Hitachi SU's not the round tops. how do i tune these? also it has had a fuel pump put in at some stage to replace mechanical pump. As far as i know there is no regulator. Should i install one and at what PSI should it be running. Cheers guys

[Datto_610]

For carb engines, I'm pretty sure you want a pump with about 5-6 psi maybe even lower? Can't help with tuning sorry but Vaughan(Classicdat) may chime in.

[beaver]

Find out what the factory fuel pump pressure was (Google should be able to tell you), and you will want to set your pressure similar to that. I suspect it would be around 2 or 3 PSI.

[1200 Koozer]

Cheers guys. I took them apart in the weekend to find that the adjustment tabs on the floats were way out and most parts on the carb were grubby so after adjusting the floats, a good clean and a baseline tune up it is running 10x better. I will eventually get a fuel pressure reg along with a new fuel line set up at some stage. Does anyone know of or recommend a pressure regulator that can be adjusted to 3 - 5psi. Also my fuel tank sender unit is stuffed i see you can pick them up on ebay but has anyone ever installed one into the tank. Cheers

[classicdat]

S 30 type sender? If they are the same as a 240Z they are as easy as. MAke usre you are low on fuel, I know not easy when you haven't got a guage, but it is just a case of twisting the retaining clip/ring and removing the sender. Careful with the 'O'ring seal and float as you pull it out. Sender is in the front of the tank, facing the half shaft.

[1200 Koozer]

Yes S30 type. Cool hopefully i dont open up a can of worms in doing soo. Is there anything i need to watch out for that could drop inside when taking it out.

[classicdat]

No there shouldn't be, the 'O' ring should come away with the sender.