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1972 z problem "help" please

Old 04-11-2013, 03:37 PM
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1972 z problem "help" please

my z been sitting in out for a good 5 years. it was running before, so now it's not. the fuel have been dried out.
Thing's i recently done to the car. I swap out the L24 to a L26.
I have sparks, but no fuel pressure. Anyone can lead me in the right dirrection?
Also, can someone post up a picture or diagram of the spark plug wires goin to the dizzy.
I need the timing degree as well.
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Old 04-11-2013, 03:50 PM
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Welcome to ZDriver!

Does it have a mechanical or electric fuel pump? I'd start with checking the pump.

Also, download the FSM for free at XenonS30
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Old 04-11-2013, 04:16 PM
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Clean the fuel system 1st

I would suggest pulling your tank and having it cleaned and most likely sealed / coated. You might need to fill the tank completely full to get the Pump to prime. Your fuel lines could be fouled with old gas glaze. Radiator shops can clean your tank for you.
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Old 04-11-2013, 04:25 PM
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i think i have a mechanical fuel pump, i can post up pictures.
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Old 04-11-2013, 04:40 PM
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1972 z problem "help" please-0411131629.jpg
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Old 05-06-2013, 08:14 PM
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Originally Posted by blue_devil_Z View Post
Yeah its definitely mechanic. Now do a fuel pressure test. It should be be at around 36.3psi. After that follow the fsm trouble shooting section in the Fuel chapter.
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Old 05-06-2013, 08:18 PM
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Originally Posted by jimbolo619 View Post
Yeah its definitely mechanic. Now do a fuel pressure test. It should be be at around 36.3psi. After that follow the fsm trouble shooting section in the Fuel chapter.
Actually for his Z it should be no higher then 10psi Tops. Its a carbed Z
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Old 05-07-2013, 04:46 AM
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Try even lower. It should be around 3 PSI or so.
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Old 05-07-2013, 04:56 AM
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Now, let's get back to the original post.
1. Are you working with fresh fuel?
2. Will the car start if you use starting fluid?
3. Have you determined how far the fuel has travelled between the tank and the carburetors?
4. Did you clean out the carburetors before trying to start? There could be lots of varnish in them.
Attached Thumbnails 1972 z problem "help" please-firing-order.jpg  
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Old 05-07-2013, 10:14 AM
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Originally Posted by BlueKitsune View Post
Actually for his Z it should be no higher then 10psi Tops. Its a carbed Z
Whoops Didnt know it was carburated . You fellas take kare of it.
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Old 05-07-2013, 04:27 PM
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yes its carburater. i have bought a new fuel pump, and i still dont get any fuel AT ALL. i dont know what is wrong. at first i thought it was the fuel pump but now i eliminated that. what can it be? and NO i didnt clean the carb, but i dont think that could be the problem that im not getting NO FUEL.
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Old 05-07-2013, 04:38 PM
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Well, let's start from the tank and work forward.

1. Does your tank have rust in it? That can clog the pickup.

2. Does your car have an electric fuel pump? (Yes, even some 72s have electric fuel pumps.) If you do, it is mounted at the gas tank. It probably has a filter between it and the gas tank, too. To see this, jack up the right rear tire and take it off. There is an access panel in the back part of the wheel well held on by some Phillips-head screws. Once you remove this panel, you'll see the right front of the gas tank. There you will either see some fuel lines going from the tank to the engine bay, or you will see a small electric pump. Ensure that there is not a clogged filter back there.

3. Check the fuel filter in the engine bay. Does it have gas it in? Have you changed it since you owned the car? They are cheap.

4. If 1 through 3 are good, then locate the fuel line between the mechanical fuel pump and the fuel rail. Disconnect the end that goes to the fuel rail and put it in a gas can. Have someone crank the motor while you look to see if there is gas flowing. Reconnect the fuel line when you're done.

5. Check the carburetors. See if the bowls have fuel. If 1 to 4 checked good and the bowls are empty, carefully put a little gas into them and close them up. Try staring the car. If it does start, try some starting fluid. Does it start then?
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Old 05-08-2013, 10:59 AM
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My car does not have an electric fuel pump, only mechanical fuel pump,
What i've try for the car so far:
1. bought a new mechanical fuel pump
2. clean the fuel hoes from the fuel filter to the gas tank. Can feel air going thru freely.
3. bypass the fuel filter, and just prime fuel directly to the mechanical fuel pump.
4. spray brake cleaner in the carbs.

Somehow there's no pressure takin the fuel. Anyone can lead me from here. really need help.
## what i'm gonna do:
1. take off the gas tank and check if it's clog in the tank.
2. check the fuse
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Old 05-08-2013, 12:44 PM
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Okay quick update. The gas tank is freely unclog. The fuel line are free as well.
I took off the fuel line while someone is cranking the car to see if there is air sucking the fuel out of the fuel tank, and I notice that there's only a tiny small amount of air pressure.
So there isn't enough air pressure to suck the fuel from tank to filter to the engine.
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Old 05-09-2013, 08:45 AM
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How much fuel is in the tank? You sure the pick-up line is submerged enough to grab fuel? Is the car on a ramp / jack stands?

Have you removed the fuel pump to manually push the lever by hand to see if it will pump / create vacuum?

Might want to pull the cam cover to make sure the cam lobe is actually touching the fuel pump lever.
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Old 05-09-2013, 02:01 PM
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i have about 3-4 gallons in the tank, the car is on the lift. does anyone have a fuel regulater?? i got a electric fuel pump, but seems like once i plug it to the battery, the pump turns on and fuel comes thru but the car wont start and then fuel starts to flow out from the carb. any suggestions, ideas?? please comment/help
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Old 05-09-2013, 02:52 PM
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Well, is it a high pressure (fuel injection) electric pump, or low pressure (carb) pump? As previously stated, these carbs only need 3-5psi fuel pressure.

Did you pull the mechanical pump / timing cover like I said?
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Old 05-11-2013, 01:14 PM
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yes the cam lobe is touching the pump lever. i got the electric pump from one of my brother's friend, and he says he pulled the electric pump off his 240z, said it was working and the pump was mainly for carb z. so for sure its low pressure. probably only 4-5 psi
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Old 05-11-2013, 01:15 PM
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does anyone have or know of a universal electric fuel pump that does not need a fuel regulater? or does it need a switch? this fuel thing is so complicated to me..please help.
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Old 05-11-2013, 04:12 PM
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If you are settled on using an electric fuel pump, here is how you can wire it safely, provided you still have the externally regulated alternator.
1. Tap into the yellow wire coming off of the alternator and run it to a relay pin 86.
2. Run pin 85 to ground.
3. Run power from the black white wire to a fuse and then to pin 87.
4. Run pin 30 to the positive on the fuel pump.
5. Run the negative from the fuel pump to ground.
The yellow wire should only have voltage when the car is alternator is turning. The black/white wire only has voltage when the key is in the ON position. This should prevent the fuel pump from running if the engine isn't turning.

As for a fuel pump, look for one for a carburetted RX-7. That should be a low pressure pump. You can see the years at Blackdragon Auto and price shop against Amazon and RockAuto.
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Old 05-13-2013, 11:36 AM
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thanks steve, i am settled on using an electric fuel pump for i heard it pumps way better than the mechanical fuel pump. as soon as i buy the parts, i will update you guys.
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Old 05-13-2013, 12:27 PM
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Unless you're running a stroker or triples, the mechanical pump should be fine. I'm not sure where your problems are coming from.
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Old 05-13-2013, 04:05 PM
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i went onto ebay looking for the electric fuel pump some guy was telling me about, "Airtex E8016S " but they dont have it for my 72 240z, does that mean i have to customize it or what?
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