LQ4 Crank Sensor
#1
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Aug 2010
Location: SC
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
LQ4 Crank Sensor
I have a question about crank position sensors on an 03 LQ4.
I am using the engine in a race car running in the "classic category" so that means no FI so I am running an MSD 6ls ignition box with a carburetor. Everything worked fine for the firsst season.
The last time i fired it up the ignition box smoked. The box is back at MSD for repairs but in the mean time i want to make sure everything else is ok.
My Question :
How do you test the crank sensor and cam sensor?
There are three wires going to each. One is power and one is signal. I guess the other is ground. when I put power on the system I have 12 volts at the power wire but also 12 volts on the signal wire. is this normal?
Thanks
Fred
I am using the engine in a race car running in the "classic category" so that means no FI so I am running an MSD 6ls ignition box with a carburetor. Everything worked fine for the firsst season.
The last time i fired it up the ignition box smoked. The box is back at MSD for repairs but in the mean time i want to make sure everything else is ok.
My Question :
How do you test the crank sensor and cam sensor?
There are three wires going to each. One is power and one is signal. I guess the other is ground. when I put power on the system I have 12 volts at the power wire but also 12 volts on the signal wire. is this normal?
Thanks
Fred
#2
Retired Senior Admin
Expert Gearhead
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 28 Likes
on
24 Posts
This test is for testing the ICM, but there are also tests for the crank and cam sensors. This should help you out.
https://www.gmforum.com/trouble-shooting-test-procedures-141/icm-test-299761/
https://www.gmforum.com/trouble-shooting-test-procedures-141/icm-test-299761/
#4
Junior Member
Posts like a Ricer Type-R
Thread Starter
Join Date: Aug 2010
Location: SC
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
bought a new sensor today. hooked it up to the harness and put power on the system. (sensor not installed in block). Found that if it trick the sensor by holding it near anything steel voltage reads 12. move the sensor away from steel and voltage reads 2.5. Stuck old sensor on plug and same results... hmmm. seems old sensor is ok.
I am curious to hear what MSD finds cause there is not a whole lot else that could be wrong. MSD has an easy hook up... power , ground and tach. all other wires are pre-fab in a harness with factory plugs. harness was working ok last year.
Fred
I am curious to hear what MSD finds cause there is not a whole lot else that could be wrong. MSD has an easy hook up... power , ground and tach. all other wires are pre-fab in a harness with factory plugs. harness was working ok last year.
Fred
Thread
Thread Starter
Forum
Replies
Last Post
PStan
Chevrolet
7
03-17-2019 02:26 PM