OK so I took off all the smog stuff, Carb blowing out feul???

Posted July 18, 201014 yr

Took all smog off, capped off all PVC stuff, then the carb by the firewall started leaking off fuel, other one is fine. I capped off both carbs and now it runs but seems rich...boggs a ton and then stalls

1973 240Z, before I capped off all the PVC system it ran great.

First thought is lean out carbs. But unsure why the one wants to leak out fuel...

FYI the carbs were changed out from flat tops to 72 round SU's before I bought it.

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July 18, 201014 yr

comment_325824

Did you remove the carbs or any fuel lines? If so you may have disturbed some dirt or whatever that is now holding the needle off the seat inside the float bowl. The removal of emissions equipment isn't the cause of your problem.

Steve

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July 18, 201014 yr

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comment_325825

I was thinking he same thing, but I didn't touch any of that stuff.

I did top off the oil in the carbs they were a little low, I am thinking float valve in that carb may be sticking.

I am messing with the mixture settings right now to see if that helps but so far no luck.

I have had 3 of these before this one and never saw this before, I am stumped but determined to get it nailed down.

Did you remove the carbs or any fuel lines? If so you may have disturbed some dirt or whatever that is now holding the needle off the seat inside the float bowl. The removal of emissions equipment isn't the cause of your problem.
Steve

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July 18, 201014 yr

comment_325829

Did you cap the vents on the float bowls? You might want to undo that.

Steve

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July 18, 201014 yr

comment_325834

Did you cap the vents on the float bowls? You might want to undo that.
Steve

I didn't notice that you did that you need air to get in, if it creates pressure it will push the float down making the gas pour in. Also I'd check to see if the float is sticking or the valve. Adding the oil should not make a big difference in the mixtures between the carbs. See if that fixes the problem. You might need to adjust the carbs a little, but you should be close so something is not right.

If you wanted to you can remove the other emission control devices and cap the smog system at the air tubes. The anti-backfire devices are not really needed without a smog pump.