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Discussion Starter · #1 ·
Hey guys I was so excited to get the 260z running today for the first time after rebuilding the carbs, changing all fluids, belts and radiator hoses. I tried getting it running and it was cranking but not starting. Sprayed some starter fluid into the carbs and started for a second then died. Took a look at the inside of the carb and realized it’s not getting any fuel. Pulled the line from the mechanical fuel pump to the fuel rail and no gas there either. Pulled out the mechanical fuel pump to make sure that the arm is in the right position, and it is. Tried to manually pump it and didn’t produce any gas. Chased back down to the plastic fuel filter and didn’t have any gas in it or gunk either. Went to the back to check the electric fuel pump, it’s definitely not working since I’m not hearing it turn on, but I was going to bypass it for now to see if I can get the car started. I was also wondering if the fuel filter in the electrical fuel pump was clogged. The weird thing is when I pulled off the electric fuel pump inlet from the gas tank, no gas came out? I have about 6 gallons of fresh gas in there, I can’t imagine it’s low on gas ? Not sure what’s causing this problem. By the way car runs good for a few seconds if I put gas straight into the carbs. Any help would be really appreciated! My last step will be checking the lines themselves, but after draining the gas tank I had no particles or any debris in there so they should be clean. Right now my problem is at the pumps, please let me know your thoughts !

Okay so after further inspection, Ive tried to vacuum (suck it out with my mouth) the fuel from the input side of the mechanical pump but no luck. I also realized that i dont have a fuel return line, and that it is capped off with a bolt (circled in blue below), will probably go buy a handheld vacuum pump tomorrow and try to see what i can do, but not sure where to go after that.
108709
108710
 

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if i were you i would try to blow the lines out with an air gun or try replace the fuel pump or take it off and try to see if thats the problem
 

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Discussion Starter · #3 ·
if i were you i would try to blow the lines out with an air gun or try replace the fuel pump or take it off and try to see if that's the problem
where should I blow the air from, from the mechanical pump to the fuel tank or the other way? I tried to take off the inlet from the electrical fuel pump and nothing came out of the tank which I thought was very strange
 

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1972 Datsun 240z
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This was happening to me a few days ago. Take off your carb filters, under them is a diaphragmatic fuel bowl. Take the top off the the fuel bowls and make sure the needle and seat are clean and fill the fuel bowls. The vacuum is strong enough to suck enough air when the car is running but not strong enough to fill the fuel bowls and keep running. Once you make sure the bowls are clean and filled you should be able to fire it up!
 

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1972 Datsun 240z
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Hey guys I was so excited to get the 260z running today for the first time after rebuilding the carbs, changing all fluids, belts and radiator hoses. I tried getting it running and it was cranking but not starting. Sprayed some starter fluid into the carbs and started for a second then died. Took a look at the inside of the carb and realized it’s not getting any fuel. Pulled the line from the mechanical fuel pump to the fuel rail and no gas there either. Pulled out the mechanical fuel pump to make sure that the arm is in the right position, and it is. Tried to manually pump it and didn’t produce any gas. Chased back down to the plastic fuel filter and didn’t have any gas in it or gunk either. Went to the back to check the electric fuel pump, it’s definitely not working since I’m not hearing it turn on, but I was going to bypass it for now to see if I can get the car started. I was also wondering if the fuel filter in the electrical fuel pump was clogged. The weird thing is when I pulled off the electric fuel pump inlet from the gas tank, no gas came out? I have about 6 gallons of fresh gas in there, I can’t imagine it’s low on gas ? Not sure what’s causing this problem. By the way car runs good for a few seconds if I put gas straight into the carbs. Any help would be really appreciated! My last step will be checking the lines themselves, but after draining the gas tank I had no particles or any debris in there so they should be clean. Right now my problem is at the pumps, please let me know your thoughts !

Okay so after further inspection, Ive tried to vacuum (suck it out with my mouth) the fuel from the input side of the mechanical pump but no luck. I also realized that i dont have a fuel return line, and that it is capped off with a bolt (circled in blue below), will probably go buy a handheld vacuum pump tomorrow and try to see what i can do, but not sure where to go after that.
View attachment 108709 View attachment 108710
Also try taking off your distributor cap and make sure that the little points are touching other than when they are on tbe high point of the bolt. It's fairly simple, the rotor cap also may need to be replaced
 

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Discussion Starter · #6 ·
Also try taking off your distributor cap and make sure that the little points are touching other than when they are on tbe high point of the bolt. It's fairly simple, the rotor cap also may need to be replaced
Thanks a lot Shane, I actually finally got her running!! basically, my issue was no gas in the line, and the pump wasn't enough to get fuel to the carbs. I ended up filling the carbs and the fuel rail after the mechanical pump with gas. getting the car to run for about 30seconds. What that did was run the mechanical fuel pump long enough to pull gas from the gas tank and into the lines. I finally had her running on her own! The only issue I had after that was the fact that I had an idle at 3k, but it was smooth. I realized my throttle linkage was set wrong, and after adjusting it I'm down to about 800-1k and she fires right up every time! I'm working on bleeding the brakes and figuring out why I have no pressure in the clutch, and when i tried bleeding the clutch slave cylinder with a vacuum pump, I'm not getting any fluid out of the system.
 

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1972 Datsun 240z
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Thanks a lot Shane, I actually finally got her running!! basically, my issue was no gas in the line, and the pump wasn't enough to get fuel to the carbs. I ended up filling the carbs and the fuel rail after the mechanical pump with gas. getting the car to run for about 30seconds. What that did was run the mechanical fuel pump long enough to pull gas from the gas tank and into the lines. I finally had her running on her own! The only issue I had after that was the fact that I had an idle at 3k, but it was smooth. I realized my throttle linkage was set wrong, and after adjusting it I'm down to about 800-1k and she fires right up every time! I'm working on bleeding the brakes and figuring out why I have no pressure in the clutch, and when i tried bleeding the clutch slave cylinder with a vacuum pump, I'm not getting any fluid out of the system.

Well try flushing the clutch line I geuss, haven't gotten that far on mine yet sorry. Let me know by replying on this thread when you solve that clutch issue, it may help me later. I'm really glad you got it running, thanks again
 

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Discussion Starter · #8 ·
Well try flushing the clutch line I geuss, haven't gotten that far on mine yet sorry. Let me know by replying on this thread when you solve that clutch issue, it may help me later. I'm really glad you got it running, thanks again
Will do Shane, good luck! There's nothing more satisfying than the car just turning on when you turn the key haha.
 

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where should I blow the air from, from the mechanical pump to the fuel tank or the other way? I tried to take off the inlet from the electrical fuel pump and nothing came out of the tank which I thought was very strange
i would take the fuel line and blow it towards the gas thank so that if anything unclogs and shoots out it wont go into your carb or into your pump and i would drain the gas out of the tank so you dont ruin and waste the new gas thats already in there and i would also check to see if your lines have been cut or crimped anywhere just in case thats the problem because ive had a car that someone put a blocker on the fuel lines
 

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late 1970 Series 1 240Z
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Just saw your post, had some suggestions. I see Shane helped you. Glad you got it running.
Ed
 

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This is really good information. Wondered why 260 has a mechanical and electric fuel pump? Usually one or the other?
 
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