Datsun Roadster Forum-311s.org

I’m having a problem where the car idles fine on flat ground and when I move onto an incline the idle drops dramatically. Under driving going up and down hills I don’t notice any issues. It’s just when the foot is off the gas pedal on a slope. Any idea where I should start?

Thanks

How steep?
I'd 1st check the line to the fuel pump from tank for flow with a vacuum pump , & cup attachment ,the line gets calciumed up
What's it do reving on the incline ?
A float prob maybe ,do you suspect flooding out or starving , but it reves fine ? See if you have a S bend in the fuel line mine 1970 did 1/8" ID new ,1/16 calciumed up

Fuel level is about the only thing I can think of that would have this kind of effect.

Just backing it out of my garage to the driveway which maybe drops 10 feet over a 30 foot horizontal distance so not super sloped I’m losing about 200 rpm at idle. Give it gas and it spools right up.

Agree with Dave ...sounds like a float level to me

That calculates to an inclined angle of 18.43 degrees, that may not seem steep to some, but when I drew it out on paper, it looked like enough to possibly effect the float levels in the nozzles, by the way the float chambers would be "tilting" the fuel towards the nozzles, maybe causing an overly enriched mixture ?

Thank you guys for your thoughts, all helpful. I noticed the seat and nozzle on the front carb is a little sticky. Not sure if that has anything to do with it. I ordered new nozzles and will report back once they are installed.

+1 (or is it +3 or 4 now ) on the float level being a bit too high.

Could also be a worn float needle & seat or even a plugged carb vent … Probably just needs a float adjustment and cleaning though.

Might also be a good time to just rebuild them