Help with LY6 installed in 2000 F-body Cam Sensor Issue
 

Bought motor as a short block. Changed the relucter wheel to 24x, opened up piston ring gaps and assembled with additional parts. Installed motor and after various issues finally started it up last weekend.

Has the issue where it is hard to start, backfires on cranking and the tach doesn't work. Seemed very similar to the one where you have to switch the outside wires on the cam sensor extension. I was thinking that was odd because I already had this issue back in 2009 when I installed a LS7 block but I switched them back anyway. It did not help. I am getting the P0342 DTC code as well.

I did a search where people said it could be the connection or loose cam retainer plate bolts.

I just hate to have to take apart the front of the motor.

Is there anything else I can try?

Thanks

That code indicates cam position sensor low voltage. Check the ground for that.

Thanks, there is a ground strap on the harness by the alternator that attaches to the engine that I have no place to attach so I didn't. Need to figure out where it is. I figured it might be the engine mount bolt that I may not have used the right bolts in the right places.

That would be awesome if it was that.

Make sure you check all the grounds on the back side of the head on the drivers side. These loose or not on will cause the same issues.

Thanks everyone. I finally attached the ground. I had to switch the motor mount bolt between the passenger side to the drivers side so that i could thread a nut to the top of the bolt. Not the easiest thing to do. Started it twice since I made the change and both times it started right up.

Ramairws6 - I had attached those grounds when I installed the harness but thanks.

Unfortunately, the tach is still an issue. When I am starting the car there seems to be some movement. Also, my efi Live is picking up the rpm signal.

Thanks everyone. I finally attached the ground. I had to switch the motor mount bolt between the passenger side to the drivers side so that i could thread a nut to the top of the bolt. Not the easiest thing to do. Started it twice since I made the change and both times it started right up.

Ramairws6 - I had attached those grounds when I installed the harness but thanks.

Unfortunately, the tach is still an issue. When I am starting the car there seems to be some movement. Also, my efi Live is picking up the rpm signal.

Well, I am still having the issue. It did seem better.

I am now thinking I purchased the wrong cam sprocket. I bought the 4X type rather than the early LS2 1X type.

So I have ordered a new one.

Yeah, 1X is the one you need. Good catch! Hopefully that should solve the issue.

Well I made the cam sprocket change and it didn't seem to fix the problem. I am not sure what is going on now but it looks like I did needed to make the change.


https://cimg4.ibsrv.net/gimg/ls1tech...6be2dcd298.jpg
X4 cam sprocket
https://cimg5.ibsrv.net/gimg/ls1tech...5e230e0130.jpg
X1 cam sprocket

Guess I'll try a new sensor. I wish I had my other motor so I could just try swapping them. My builder has had it forever.

It works! I have two of the short harnesses that go on the front of the timing chain cover. When I had the wrong sprocket (the 4x one) and was having the issues I switched the wires on the harness that I used on my last motor. After I installed the new sprocket, I was thinking that the wire harnesses were different. I decided to take a closer look and changed my old harness wires back and now it's working. Thank god.

I haven't run it too much but the tach is working and it started up without a delay.

Good feeling ain't it. LOL