Location of crank position sensor on 3.1L

[Red_Lumina91]

Can someone tell me where to find the CPS on my 91 Lumina w/3.1L engine? I looked through a Hayes manual and they dont even mention the part.

[Red_Lumina91]

I ask because I have just read a couple of things such as it's ...."Under hood, center, rear engine area, passenger side of exhaust pipe, above oil pan, mounted in engine block"

I also read...."Where is the crank sensor located on a 92 lumina with a 3.1?.... repair manual states it's on lower right side of engine in front of crank pulley but cant find it?" ....It is located on the back side of the engine, you will have to roll the engine forward and remove the alternator and alternator bracket to get clearance once thats done you'll need a mirror to see it, it will be held in place with 1 bolt (removed with 5/16" socket) and have a wiring harness connected to it with 2 wires 1 purple and 1 yellow.

Is this easy to replace... or do I have to roll the engine forward etc, as suggested above?

[kevinb70]

what you are describing is a two CKP sensor system.

One is located behind the crank dampener which is HARD to get to

The other is kind of hard to get to because it's hard to see it. If you are getting random engine shutdowns, check the wire going to the OTHER sensor - the exhaust may have burned thru the insulation and it could be randomly shorting out against the exhaust.

The CKP sensor is located on the side of the engine facing your dash firewall. The sensor is about 8-12 inches below the middle rear spark plug.

Check the side of the engine for the two wires leading down to that area. They'll be in a plastic wire loom so peek inside to see if the colors match. This set of wires will split from the main harness loom somewhere near your intake manifold, and go straight down along the engine - again on the dash firewall side.

Small arms - this sensor can be changed by laying with your chest on the intake manifold and reaching down with your right arm

[Red_Lumina91]

Thanks...I'm going out to the driveway now to take a look.

[Red_Lumina91]

Thanks for the info on locating the CPS. I managed to get at it by turning the passenger side front wheel all the way to the left. I jacked the passenger side of the car high off the ground. Lying under the car with my legs facing the rear, I then was able to fish my left arm in through the steering mechanism and SHOVE it far in between the block and firewall. This was a very tight squeeze. Talking about needing lots of patience. My arm and hand had to bend in ways that I didnt think possible. Once I actually found it...it took all of about an hour and a half to get it out and put the new one back in it's place. I was able to somewhat use my right hand from bellow. It helped guide the 1/4" wratchet that I was holding in my left hand. I used a 5/16" socket with a short extension to remove the single retaining bolt. I wouldnt want to have to replace another CPS anytime soon.