CTZCC.COM
http://forums.ctzcc.com/

240Z tuning
http://forums.ctzcc.com/viewtopic.php?f=4&t=8456
Page 1 of 1

Author:  Bill B [ Tue Sep 16, 2014 9:59 am ]
Post subject:  240Z tuning

Hi, I purchased a 72 240Z with a fresh engine that has not been tuned. I've taken it to two different shop who said they could adjust it to run right. No success. They say it's idling at about 3500 RPM and don't know how to bring it down. Can anyone recommend a shop that can dial this car in. Thanks, Bill

Author:  Frank T [ Tue Sep 16, 2014 11:24 am ]
Post subject:  Re: 240Z tuning

Without reservation or hesitation, please call Vinny Bedini at his New Milford shop: 860.335.182(nine). He has been fixing Zs for more than 40 years and does most of our Club engine, driveline, brake and suspension work.

On a positive note, it won't take long to break your engine in if you leave it idling that way! :lol:

Frank

Author:  Bill B [ Tue Sep 16, 2014 1:27 pm ]
Post subject:  Re: 240Z tuning

Thanks Frank, I'll give him a call. I can't wait to start driving it.

Author:  porkbun [ Tue Sep 16, 2014 9:05 pm ]
Post subject:  Re: 240Z tuning

SU carbs? If you were a little closer(30 mins outside of sturbrige) Id stop by and give it a shot but if you couldnt get a hold of Vinny you could check out the EF Engine fuel section in the factory service manual to figure out hot to setup your carbs http://www.xenons30.com/reference.html

Author:  Frank T [ Tue Sep 16, 2014 9:50 pm ]
Post subject:  Re: 240Z tuning

Shouldn't he make sure it isn't a vacuum leak, or a stuck vacuum piston, or a burred linkage, or tight valve lash, or something else before he starts 'tuning' his SUs?

Mechanics at two shops have tried to 'tune' them and they can't get the idle down. I would suspect it would be something outside the normal 'tuning' routine which is preventing it from settling down to a normal idle.

If they don't work with a lot of old 240s, they probably don't know what the linkage should look like or be adjusted, or where the vacuum chamber pistons should sit, or how the two SUs should be coordinated. This is a freshly rebuilt engine, newly installed. Nothing says it was installed correctly or that the linkage fits right, or that the carbs have been properly installed. I would suspect something fundamental has been overlooked or maladjusted and fix that first, and leave carburetor 'tuning' until the final step.

If he has a vacuum leak or a hung vacuum chamber piston or a short linkage or tight valve lash, all the 'tuning' in the world won't bring the rpm down. They need to resolve the coarse problems first, then finish by fine tuning the carbs last.

Author:  porkbun [ Tue Sep 16, 2014 10:59 pm ]
Post subject:  Re: 240Z tuning

I agree 100% about carbs being last especially since Ive messed with carbs so many times at so many different stages of my refresh. Valve lash is usually my first piece of advice before touching the carbs since I had to tune my SUs every time my old 260 warmed up until I figured out what it was. Since I change carbs every few months (if not weeks!) Ive had vacuum leak issues, nubs on the throttle linkage issues, float issues, stuck piston issues, stuck choke issues etc. I did assume the shops didnt know what they were doing, everything else was set up properly, and the carbs just needed to be tuned. Nice snag since I didnt think that through :lol: :thumbs_up:

Author:  Paul [ Wed Sep 17, 2014 7:33 am ]
Post subject:  Re: 240Z tuning

I can tune those for ya with a blind fold and rubber hose.........but I have a meter as well. I'm in RI.

Author:  Frank T [ Wed Sep 17, 2014 8:32 am ]
Post subject:  Re: 240Z tuning

Bill, our member Paul has his Master Mechanic certification and Zs are his hobby. He drives a very nice S30 and he's actually pretty close to you. We trust him.

(PS ~ he doesn't really blindfold himself while working around moving fan blades and belts. He just knows enough about these cars to work on them in his sleep if he had to).


Frank

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/