resurrecting a 1977 280Z

[Yarb]

Buy one that includes the gauge as an assembly 

[Racer X]

12 hours ago, MM569457 said:

A few weeks ago the front carb did spit out fuel through the vent hose ontop of the float chamber. I'd assume the best place for a regulator would be after the mechanical fuel pump before going into the fuel rail?

Yes. 

Wait.

Does your car have an electric fuel pump also?

Sorry, I had to think about that for a moment, because on the race Z there isn’t a mechanical pump, only two electric pumps at the fuel cell. My stock 72 Z only has the mechanical pump, in fact the system is the original equipment from 1972, no electric pump, and no added regulator.

So if your car has both an electric and a mechanical pump, between the electric pump and the mechanical pump should be OK. 

The stock mechanical pumps shouldn’t produce too much pressure, as they were designed to supply the carbs without a regulator. You might want to check the pressures in the system. That will help you understand what is happening, and why fuel is spilling out from the carb throats. 
 

As dirty as the float bowls were, the problem may not have been too much fuel pressure, but rather dirt in the needle and seat, allowing the bowls to overfill.

[MM569457]

I have an electric fuel pump installed, but its currently not routed into the fuel system. It couldn't push fuel to the engine including the mechanical pump. But currently it only has the mechanical fuel pump running fuel to the carbs. The fuel running to the carbs is clean, my best guess is there was fuel in the bowls while the engine sat for 15 years. 

[MM569457]

20 hours ago, Yarb said:

Buy one that includes the gauge as an assembly 

I assume this would work.

[Racer X]

20 hours ago, MM569457 said:

I assume this would work.

Never assume.

I made my recommendation.

 

[Zed Head]

23 hours ago, MM569457 said:

I assume this would work.

That's an odd one.  Looks like it has a vacuum reference port, which a carburetor would not need.  But a 10 psi gauge which is way lower than any EFI system.  Post the link, can't even tell what brand it is.  Looks like eBay.

[MM569457]

https://www.amazon.com/Universal-Adjustable-Regulator-Injection-Accessories/dp/B08S757C76/ref=asc_df_B08S757C76/?tag=hyprod-20&linkCode=df0&hvadid=507600687300&hvpos=&hvnetw=g&hvrand=15473091677829872037&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=200524&hvtargid=pla-1212457430535&psc=1

[Zed Head]

I wouldn't use it.  A decent gauge, those hose clamps, and pieces of hose would cost over $25.  

It's universal because they can change the ad copy to fit any application.  140 psi.  "adjusts oil flow"?  "ideal weight"?   Not good...

 

• Fuel Pressure Regulator Kit: Prevent stalling, flooding, and other drivability problems by making sure your carbs are getting the right amount of fuel pressure with MOJTBE products.
• Adjust Capacity: This Aluminum Fuel Pressure Regulator Kit is adjustable from 0 to 140 PSI maximum fuel pump capacity. Optimally adjusts oil flow to meet your car's fuel pressure requirements.
• Materials: Premium aluminum construction for ideal weight and superior durability.
• Package Includes: 1x Fuel Pressure Regulator, 2x Hoses, 1x Accessories.
• NOTE: Not Legal in the state of California & New York, Not complies with C.A.R.B. regulations, Not for sale in the states of CA and NY. No instruction or direction included in the package, Professional installation is highly recommended.

Edited April 12, 2023 by Zed Head
too many any's

[Zed Head]

These look decent.  Holley has been collecting brands and rebuilding their reputation so quality is probably fair.  A selection of psi ranges.  You would want the second one, I think.

https://www.summitracing.com/search/part-type/fuel-pressure-regulators/product-line/holley-fuel-pressure-regulators?SortBy=Default&SortOrder=Ascending

 

 

[Yarb]

If you’re that concerned about it just put a fuel pressure gauge between the pump and the carbs. IMO Adding too many variables for failure in the future.

[Zed Head]

Once the pressure is set the gauge can come off.  No real need for a permanent gauge.  

[MM569457]

Thanks for the pointers. An update. I adjusted the floats appropriately per specs, had a mechanic friend assist (he be doing a lot for free/beer/steak/etc.)

Zcar parts came in, gaskets and last chance filters. Installed them onto the carbs.

The front carb almost immediately had fuel gushing through the vent line. Removed the front float and raised the metal tab, using the blow method.

Rear carb had fuel leak, but found the source was the banjo nut where I installed the filter. Tightened it down. Car ran for 15 minutes about the same. Not sure if it’s lean, but it’s not rich. It’s probably within the ball park to take to a specialist for tubing.

I installed the new Coolant Sending unit. Temp Guage now works.