My 73 Z recently started to sputter and stall when accelerating from a stop. Over 10 mph its fine and it idles fine just on the initial stepping of the gas from a light or stop sign. I believe it has the 71 or 72 carbs, definitely not 73's. I have had the car for 5 years and have not touched the carbs since I have no idea how to do anything with them. Do you think they need to be rebuilt (assuming it’s a carb problem)? Any recommendations? I have seen that Z therapy is mentioned in high regard but do I have to buy a new set or will they fix mine?

Check the damper oil in carbs under the black thumb screws, might be low.

Check the damper oil in carbs under the black thumb screws, might be low.

How do you tell if they are low? What would you fill it with? Sorry if the questions sound stupid. I don't know anything about the carbs.

Download copies of the FSM and owners manual, then. Learn about maintaining your Z, and you will reap the benefits of classic car ownership.

If you lift up on the suction pistons and they offer no resistance they are out of oil, you will see two lines on the plunger rod, make sure the oil is between those lines. It's ok if you over fill it, and use 20wt oil.

Download copies of the FSM and owners manual, then. Learn about maintaining your Z, and you will reap the benefits of classic car ownership.

Well I have a 73 manual but these are different carbs (not sure which year). I can do most anything else including painting the car but zero experience with carbs. Always sent them out on my other cars (American Muscle). The benifits of owning old cars is also learing how to deal with your frustration on making them work:) and having the time to work on them. There is lots of satisfaction when you fix something but today I am willing to forgo that satisfaction.

If you lift up on the suction pistons and they offer no resistance they are out of oil, you will see two lines on the plunger rod, make sure the oil is between those lines. It's ok if you over fill it, and use 20wt oil.

Thank you. I will take a look when I get home.

Also check your chokes and make sure that they are not sticking slightly open this can also cause your car to sputter.

Just throwing it out there, when I had my 71 240 i was running the su's and I always used ATF in my carbs and filled them right above the low line on the rod. It ran great from me with that set up.

I'd like to add in that I'm having a very similar problem on my 71 240z. When the engine is cold, even if I let it idle for a few minutes, it tends to hesitate badly and then "pop" back to life after a moment. Once it's warmed up, it's perfectly fine. Even if I let it sit for an hour or so, if it's still somewhat warm, there are no problems.

I checked the oil level in the carbs, and it appears to be fine...almost exactly dead center between the two lines on the rod. I looked through the service manual, but aside from tearing everything apart and checking each piece individually (which I'd really prefer not to do) I'm not quite sure what other steps to take.

My 72 sounds more like V8 when cold, its not sputtering but not running with all the cylinders. I have warped distributor, also i dont get all the power Z has to offer when i hit the pedal to the metal.