My LT1 tach used to idel 900ish but after whiteface gauges its 700ish. I heard the stock tach is a couple hundred high anyway so I was wondering if its MORE accurate now. So whats the stock idle? THanks.

 

Is your car an A4 or an M6. The factory programming for idle, engine fully warmed up, is:

M6: 800rpm

A4: 650rpm in neutral, 550rpm in gear.

Remember, the typical stock tach reads 100-200rpm higher than actual rpm, so as noted above, you can only tell the true rpm by looking at the PCM with a scanner.

 

my tach is 250RPM higher than the scanner

 

Alright, I think Ill leave it where it is at 700 warmed up in neutral. Thanks for the info guys!

 

As per a GM OBD1 scanner, my '95 A4 Z28 idles idles at about 675rpms in P when fully-warmed up...And as Injuneer stated, the factory warm idle speed should be 550rpms when in gear...

BTW, like everyone else, my tach seems to read 100-150rpms higher too...

Mike

 

Are the guages just overlays? If they are, when you put them on did you remove the needles?