I have replaced the throttle body and need to verify engine speed
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1993 GMC Sonoma Question: Where do you connect a tachometer to check the Revolutions Per Minute at an idle
Answer #1G. T. Service Center (4177 Answers) , Stephenville, TX - (254) 638-3236ProfessorG February 21, 2014, 17:45Master
Negative side of the coil.
Replyscarf, February 21, 2014, 18:51Rookie
There are 5 wires running to two separate plugs, which one is negative, and do I pierce the wire?
ReplyProfessorG, February 21, 2014, 19:54Master
The white wire with the pnk/blk, the other white wire is a digital signal for the instrument cluster, if the tach is digital use that one.
Replyscarf, February 21, 2014, 20:47Rookie
Thanks a bunch
ReplyProfessorG, February 21, 2014, 20:49Master
I was tied up earlier, No Worries.
pushrod February 21, 2014, 21:27Master
Engune idle speed is not adjustablle! That screw is only a throttle stop, ecm has control over idle through IAC valve!!