my 240Z doesn't run properly until warmed up. is this normal?

[regggggggg]

I have a 1972 240Z. Pretty much stock L24 but i do have 2.25 diameter exhaust piping running from the stock headers and with a Magnaflow muffler.

 

Now be aware that I am pretty new to carbureted engines and I've been told that they do need warming up.

 

But what boggles my mind is that I was at a meet today with another 240Z with pretty much same setup except he was able to just start his car and drive off with no problem. Whenever i try that, my car would struggle and sometimes the engine would die out. Even if i were to just rev my engine while the car is parked, it would make a pop sound and the engine would cut out for a moment but then continue to run.

 

Once my car is at normal running temperature though, it would run perfectly fine. Is there something wrong?

 

any input would help.

Edited August 13, 2011 by regggggggg

[zforce]

I have a 1972 240Z. Pretty much stock L24 but i do have 2.25 diameter exhaust piping running from the stock headers and with a Magnaflow muffler.

 

Now be aware that I am pretty new to carbureted engines and I've been told that they do need warming up.

 

But what boggles my mind is that I was at a meet today with another 240Z with pretty much same setup except he was able to just start his car and drive off with no problem. Whenever i try that, my car would struggle and sometimes the engine would die out. Even if i were to just rev my engine while the car is parked, it would make a pop sound and the engine would cut out for a moment but then continue to run.

 

Once my car is at normal running temperature though, it would run perfectly fine. Is there something wrong?

 

any input would help.

Make sure your nozzles are dropping when you pull the choke lever, also check your mixture, might be slightly lean.

Edited August 13, 2011 by zforce

[Miles]

Somewhere on this site I thought I saw a tutorial on tuning SU carbs. Also, Z Therapy sells a video called "Just SU" which explains the care and feeding of SU carbs. I have a copy if you are interested. Takes you step by step through the tuning process.

 

Could be something as simple as adjusting the mixture settings or making sure that the choke is working. The Classic Z website has a lot of good info on tuning SUs.

Edited August 13, 2011 by Miles