LQ4 Cam/Crank Waveform

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Nov 13, 2025 | 06:58 PM

JoeRJr

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Staging Lane

Joined: Jul 2018

Posts: 76

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LQ4 Cam/Crank Waveform

I am tuning a truck for a friend. It's a 2000 1500 that has had an LQ9 installed with a Truck Norris Cam in it. I've tuned a good bunch of these without any real trouble, but this one is eating my lunch. I had real trouble getting it to start initially. With Base running airflow doubled and about 25% cranking fuel taken away it'll start. Once you shut it off, you have to disconnect the battery in order to get it to run again. I figured I get the SD and MAF tuning done to see if it helped, but it didn't. It also won't idle with anything less than about 20 degrees of timing. When it tries to start it pops out the exhaust, but that's it. When it does run, it tunes OK, but it sure doesn't make any power. This isn't normal for this cam. Not in my experience. I checked my cam timing with a scope and it looks to be a bit behind. I pulled the cover and the marks line up.
Here's 2 scope images. One from my LQ9 swapped truck,, and one from this truck. They're certainly different, but I don't know if it's in the Normal Range. Has anyone been down this road before? The first image is the problem truck.
Any advice welcome. Any abuse will be graded on a curve. :-)
Joe