According to my tach my truck's idling at just a hair under 500...
It's a little rough, but it manages just fine, I'm just a little concerned because the idle is so low that it could cause a problem somewhere?
I have 2.5" pipes, short air intake w/ cone filter & an electric fan...

 

My 85 22re is supposed to idle at 750 and it does. Using a tester.


Also a while back my battery was failing but all I notcied is the idle was too low(before I had a tester) and my electric compass would shut off due to power drop at low idle. Low Charging and having it die like when you put it gear(auto) and low oil pressure are the only downside of low idle I can think of.

My dash tach says 500 when the actual idle is 750.

 

Is this a 22r or RE? Is the poor idle related to temperature? And, how's it running otherwise?

 

Thanks pcmentor, i'll look into another tester

it's a 22re, runs cool, no problems whatsoever

 

I got a Sunpro Model CP-7678 meter that has low/hi tach function, also duty cycle for injectors. I found a used one at auction for $5 plus $8 ship. You can get a brand new one for $35. I also just bought an Actron timing light with RPM for $70 free ship at Amazon.

 

If the idle is too low a few things will be negatively affected:
oil pressure
connecting rod bearings and wristpins
timing.