260z Fuel lines

[Npdavies.]

So my '74 260z went out on it's maiden voyage today and we ran into a few issues.

After a couple hundred yards the engine started shaking and basically killed itself.

We managed to pull it over on a side-street and popped the hood. Nothing had changed, nothing was on fire or had exploded so that was something.

We sat around for a few minutes then tried starting it again, and it started right up, idled perfectly fine and we drove it back home with no issues.

 

So we were thinking maybe since the fuel lines wrap around the valve cover perhaps the fuel heated up in the float bowl and led to vapor lock, which killed the car.

Which leads to my question: is there a way we should re-route the fuel or something? Is vapor lock a common problem with this fuel setup?

The engine is still all stock, L26.

[Z-train]

So my '74 260z went out on it's maiden voyage today and we ran into a few issues.

After a couple hundred yards the engine started shaking and basically killed itself.

We managed to pull it over on a side-street and popped the hood. Nothing had changed, nothing was on fire or had exploded so that was something.

We sat around for a few minutes then tried starting it again, and it started right up, idled perfectly fine and we drove it back home with no issues.

 

So we were thinking maybe since the fuel lines wrap around the valve cover perhaps the fuel heated up in the float bowl and led to vapor lock, which killed the car.

Which leads to my question: is there a way we should re-route the fuel or something? Is vapor lock a common problem with this fuel setup?

The engine is still all stock, L26.

 

 

Make sure the return line is functional.

[ggzilla]

Yes that was how Datsun fixed the problem, they added the fuel return line.

 

The EFI Zs are worse, they added a little fan to prevent overheating, didn't they?

[datzenmike]

A few hundred yards isn't enough to get hot. Check the fuel filter too.

[Skib]

Is vapor lock a common problem with this fuel setup?

The engine is still all stock, L26.

 

its super common on 260's. pretty much every time I see them they have heat wrapped fuel lines.

 

 

 

they added a little fan to prevent overheating, didn't they?

 

 

lol yeah, the 280zx has a fan on the pass side of the block that blows on the injectors.

runs for like 10min after you shut it off.

[Npdavies.]

Alright guys, thanks for the quick response.

We actually didn't have a return line connected when we made our little trip...

 

And also, the temp gauge in the car goes 120-250 degrees and it was running in the dead middle during most of our ride.

Should that be normal/should we consider replacing the temp gauge? Since we have an all new thermostat and all that good stuff.

 

Thanks again guys.

[Ranman72]

on 260 they had a fuel vapor problem most were wraped in a silver cooling shield to help prevent this

[Skib]

 

We actually didn't have a return line connected when we made our little trip...

 

hook one up and report back ;)

 

And also, the temp gauge in the car goes 120-250 degrees and it was running in the dead middle during most of our ride.

 

thats fine

[Npdavies.]

Well it hasn't been started for a while. :P

My Z has been up on blocks for a while now, and we're trying to figure out tire sizes.

I'm thinking 205/60-16 on a 16x7 Motegi FF7 wheel.

With that size on a stock Z, there shouldn't be any rubbing as far as we're concerned.

But I'll try and post some info on how it runs after we reconnect everything that should be connected. :)

[Npdavies.]

Well to be completely honest, the Z starts up and idles perfectly. Starts better than the Suzuki we have in the driveway. ;)

But since it's up on blocks at the moment with no brakes and no suspension I don't think it'll be driven for a bit. :P