engine starts runs for about 30 seconds or less

[duckman30]

So i bought a nissan 720 with the z24 engine in it. I did a carb kit and has been running flawlessly for about 2 weeks now. today i went to leave in it and it starts and runs for about 30 seconds or less then shuts down and wont restart. Took the carb off again and rebuilt it again just making sure i didnt plug a port or anything.

and put it back on started for 30 seconds then died.

any ideas of what i could be that is making it die?

any help is very appreciated!

[sstroudwku]

I know this sounds sarcastic but I've made this mistake. Fuel pressure and fuel in the tank?

[duckman30]

Plenty Of Fuel How Do I Check Fuel Pressure?

[sstroudwku]

easiest way is to remove the feed line from the carb, put an inline fuel pressure gauge in, and plug it back into the carb. Crank the engine over several times with the distributor unplugged. Read the pressure. Sounds to me like the bowls are draining quicker than filling.

[duckman30]

i will give that a try! any idea where it should be on the gauge?

[sstroudwku]

old 720 I believe is 11psi, it's not much at all.

[duckman30]

Okay i checked the fuel pressure it is good i sprayed starter fluid in it and it wont start now, any other ideas of what could be wrong?

[sstroudwku]

do you have the supply and return lines swapped?

[PEZi]

Fuel relay... fought the same problem for 2 years. Get one for around $50 with a warranty and never worry again!