72 Z wont start.

[NCdatsunZ]

I have a 72 with a completely stock l24. The car was a barn find and I have been restoring it.

I did the Ztherapy carb rebuilt kit, Replaced the fuel pump and all the fuel lines. The gas is definitely getting to the carbs because when I disconnect the line above the carb, gas comes out. I sprayed starter fluid into the carbs and crank it. It revs to about 3000 rpms, idles for maybe a second then dies. What should I do next to get it started?

[NCdatsunZ]

Is it possible that the intake manifold is somehow clogged? or did I somehow screw up the carburetor rebuild?

[Hardway]

Congrats on your barn find and for working to get it running. Does it smell rich when it runs? If so your floats may not be set just right. The SU carbs are sensitive to their float setting. Are you using an electrical or mechanical pump? If its electrical it could be pushing too much pressure. What do your spark plugs look like?

[Captain Obvious]

I did the Ztherapy carb rebuilt kit, Replaced the fuel pump and all the fuel lines. The gas is definitely getting to the carbs because when I disconnect the line above the carb, gas comes out.?

Just because you are getting fuel in the lines that lead to the carbs doesn't mean you are getting fuel INTO the carbs.

Before it actually gets into the float bowl in order for the engine to use it, the fuel has to get through the screen filters and past the float valve. You might have something wrong with the filters, a stuck float valve, or a badly mis-adjusted float.

I'm making a distinction between TO the carbs and INTO the carbs.

[LeonV]

Check that your nozzles move smoothly.

Sounds like it could also be a large vacuum leak. Is there an unplugged hole in your balance tube?

[NCdatsunZ]

Congrats on your barn find and for working to get it running. Does it smell rich when it runs? If so your floats may not be set just right. The SU carbs are sensitive to their float setting. Are you using an electrical or mechanical pump? If its electrical it could be pushing too much pressure. What do your spark plugs look like?

I've got a new mechanical pump and the new spark plugs appear to be clean. It hasn't been running long enough for me to tell if it is running to rich.

Just because you are getting fuel in the lines that lead to the carbs doesn't mean you are getting fuel INTO the carbs.

Before it actually gets into the float bowl in order for the engine to use it, the fuel has to get through the screen filters and past the float valve. You might have something wrong with the filters, a stuck float valve, or a badly mis-adjusted float.

I'm making a distinction between TO the carbs and INTO the carbs.

I pulled the float bowls off and ballpark adjusted the floats. I checked the valves, they are not stuck. and there is no ''last chance" filter. Still wouldn't start.

Check that your nozzles move smoothly.

Sounds like it could also be a large vacuum leak. Is there an unplugged hole in your balance tube?

I took off the jet nozzles and gas came out of the tips, and the move smoothly.

I will check for the hole in the balance tube, this is a possibility.

Could it be possible that my ballast resistor is faulty? I read somewhere that someone with a similar problem switched out their ballast resistor and it worked. They also noticed the fuel gauge giving a wrong reading. My fuel gauge says it is full, and there is about 4 gallons in the tank. I recently restored the gas tank and installed it myself, it is possible that I put the fuel sender in upside-down.

[Captain Obvious]

I pulled the float bowls off and ballpark adjusted the floats. I checked the valves, they are not stuck. and there is no ''last chance" filter. Still wouldn't start.

Could it be possible that my ballast resistor is faulty? I read somewhere that someone with a similar problem switched out their ballast resistor and it worked.

That's great. Did you actually check that there is fuel getting into the bowl? You did the bench set-up, but you didn't verify that it worked.

Sure you might have a faulty ballast resistor in addition to other problems, but a faulty ballast resistor isn't temporarily fixed by a blast of starter fluid.

Start simple... Pull the hose off between the bowl and the nozzle and use a clear tube to measure the bowl level as described in the manual.

[NCdatsunZ]

Ok, I suppose I have gotten a little ahead of myself here. One of the vacuum lines cracked and broke. I'm going to go through and replace them, then use the manual to properly adjust the float level.

Thanks for all the help!!!

[Reverend]

I had similar issues and it was the ballast resistor, cheap to replace

[felixcatman]

Did you try opening up the needle nozzles in the SU carbs to get enough fuel to the cylinders?

[NCdatsunZ]

I had similar issues and it was the ballast resistor, cheap to replace

Replacing it today anyway. I'll be very happy if this is all it needs.

Did you try opening up the needle nozzles in the SU carbs to get enough fuel to the cylinders?

What do you mean by opening up the needle nozzles?

[NCdatsunZ]

Replaced the ballast resistor and tried to crank it. It ran for longer and idled at like 400 rpms, then died. The ballast resistor was smoking after it died. It wasn't getting fuel either. I took the fuel line that comes from the fuel pump to the carb and pointed it in a cup and had somebody crank it. It wasn't pumping any fuel. I got the fuel pump new at autozone. What should I do next, this is becoming very frustrating.