Engine/Transmission (1994 - 1998) checking your tach

[BWiser]

when you read how to set your idle speed it brings up a tsb saying that your factory tach is off and use a different tach to set the idle where do you hook one up?

 

[KingS]

some say tach is off but I don't know. My tach seems to be dead on in mine at least when I set my idle I used the way the truck sounded once in gear and ac on ect. once it sounded right I locked the idle in place got in the truck when done and the tach read when in gear about 2 to 2. 5 needle widths above the 500 mark which to my eye means my truck and tach are right on but some trucks could be different.

 

[Highfinance97]

I installed A Autometer 5" tach and the two are about 1-200 RPM's apart







Michael

 

[JFaughn]

The crank sensor
You should fill in the info for your truck , easyer to hell .
There are a couple tools for checking RPM with no hook ups , not cheap , starts at $300 + .