RPM at idle??

[mrpbody]

I have just installed an Autometer Tach that runs off of the pulses on the alternator. The instructions state that it has to be calibrated at cruise speed or by a shop with the equipment to do so. I'm driving it out of town this weekend and would like to get it close, and then when time permits I will have it calibrated with the proper equipment.



According to the tach my truck idles in park at 400 rpm, and I know this is not accurate. What should it be idleing at?



If it makes any difference, I have a 1st gen, bone stock, with automatic trans.



Thanks,

marty

 

[GeraldGordon]

I think my Idls at like 900 rpm I set my by Going 70 mph in 5 gear at 2. 5 rpms

 

[TKingsbury]

My hot idle in neutral is 750-800 rpm.

Travis. .

 

[BushWakr - RIP]

Adjust your idle till the drivers mirro gets the "wobblies"... that will be darn close to 700 RPM. Set your tach from there... . you'll be close until you can get your hands on an optical tach to fine tune it.



pb... .

 

[Greenleaf]

My idle is a hair shy of 800. When in gear it drops, then the heat makes it drop, then the A/C makes it drop etc. etc. etc.



Scott

 

[paccool]

Mine is set the same as Greenleafs. 800 is where it should be and that is in gear, not neutral.