Datsun 180Bsss won’t run - please help

[D180BsssHead]

Hi, 

I’ve recently run into a problem with my Datsuns. I had two 180BSSS coupes, one 1973 one 1976. They both 1.8L engines factory with twin SUs. 
 

They have both had the same issue, which I’ll get into shortly, but leads me to believe this might be a common problem. 

Now I don’t know too well, but what’s happened is one car has been stored for about 4 years and the other stored for 2 or 3 there abouts. The one I stored for four years was completely neglected, never started once in that period but the other one did but I reckon it was untouched for about 3-4 month before trouble started. 

they both start and fire but will only run for a couple minutes before what seems like the engine is being starved of fuel. I have changed and tried about three different fuel pumps on both motors but still no luck with that. What seems to happen is the fuel pump will suck up fuel initially, which I can see by the fuel filter being full, and then after 2-3 minutes it runs dry and won’t start again for a couple hours. Also they wont idle without the choke in that 2-3 minutes.  
 

I’ve checked and confirmed the fuel tanks aren’t blocked by removing the hose at the tank end and fuel flowed out nicely. 
 

Ive disassembled, cleaned and reassembled the SUs on the car I stored for 2-3 years right before I stored it so I’m pretty confident they’re sound. 
 

Wondering if anyone might have any ideas on twist this could be? This was also happening in the middle of winter < 10 degrees Celsius so I’m skeptical this could be a vapour lock considering these have sat for long periods between me trying to tinker with it. 

[gav240z]

What fuel pump are you using? Mechanical or electric?

[Enzo]

If using the mechanical fuel pumps, disassemble one to see if the rubber diaphragm is perished.

[AndBir]

13 hours ago, D180BsssHead said:

I’ve checked and confirmed the fuel tanks aren’t blocked by removing the hose at the tank end and fuel flowed out nicely. 

Are you using the old fuel? Sometimes old fuel can clog up the fuel filter with a type of paraffin/wax compound.

[D180BsssHead]

It’s a mechanical diaphragm one, I have tried this on one of the pumps but that didn’t fix anything. All three pumps I’ve tried seem to displace fine. When I take them off and crank it physically the last of the fuel spits out

[D180BsssHead]

2 minutes ago, AndBir said:

Are you using the old fuel? Sometimes old fuel can clog up the fuel filter with a type of paraffin/wax compound.

Have also tried fresh fuel. One of the fuel tanks was blocked on the car I had in storage for four years. I soaked it in kerosene for a month and unblocked it so yeah had to refill with fresh fuel. 

[610sss]

On 11/21/2023 at 8:30 AM, D180BsssHead said:

Have also tried fresh fuel. One of the fuel tanks was blocked on the car I had in storage for four years. I soaked it in kerosene for a month and unblocked it so yeah had to refill with fresh fuel. 

Hi, did you have any luck with this issue, I am also experiencing the same symptoms on the 73' SSS?? Did you end up finding the root cause?

 

Thank you.