I'd like to get some opinions from as many as possible regarding idle rpms. All of you Z enthusiasts out there may have a slightly different theory on correct idle rpms specifically related to the 240 model years. As we all know the manufacturer recomended 650rpms was the the proper setting for idle speed. The manual I believe noted 650 along with the original sticker on the air filter housing. If I'm not mistaken the sticker on the inside of the hood said 750 and about everyone I speak with sets there idle 800-900 to alleviate the "bounce" of the engine at idle. Can I get your thoughts on this and does a higher idle make the car run hotter, use more fuel or is there any downside to setting the idle higher. Not the high idle just standard idle rpms. Look forwared to hearing your opinions.

Burt

cardogman1

Hi Burt!

I set the idle on my car to the 800-900 rpm range, and have not noticed any heating issues. Since more rpms does indicate more firings per cylinder I suppose the car does use SLIGHTLY more gas at idle than if a lower idle rpm is set, but my car doesn't remain at idle long enough for this difference to be noticable in terms of gas mileage. I haven't noticed any downside in my experience.

It'll be interesting to hear what others say about this

Carl

P.S. Money Order is at the Post Office (please let me know when you receive it, if you can) Thanks again!

A lot of this will have to do with the condition of the engine itself.

A completely rebuilt engine ( from top to bottom including carbs and ignition) will probably tolerate a lower idle speed. Then you need to take into account any modifications made to the engine, cam choice, timing etc... An older engine with high miles will probably need a higher idle speed, as will one in less than perfect tune.

Best thing to do is to lower it till the engine starts running rough, then increase it until the engine is idling smoothly and leave it at that.

Thank You Mr. Bambikiller for the feedback and I'll get back to you when I get it carl.

Thank you Mr. 2manyZs Thats good advice . The car was recently tuned with everything done and it does as you know have very low mileage. I distinctively think that none of these cars ever idled comfortably at 650 and based on my informal poll I think I'll raise the idle to at least 800-900 it's just smoother and the shifting won't be such a drag on the clutch.

Be well Burt the cardogman