I'm still getting M&S lights flashing every few start ups so I clear the code for every drive (4 drives so far of a few min each), Crank position sensor error shows so I'm sure I need to fine tune there but the tach works fine it seems....... "1/6th inch or 1.58mm" spec is given.

I'm a little surprised by this as I have it less than 1mm away when I first installed it. I can slip 2 business cards through the gap just barely. I'll have to bust out the feelers and gauge this. Perhaps I'm too close? Can anyone with some experience give us all the feeler gauge specs that worked for them? I think the manual stated a bigger gap but yesterday I played with a bigger gap and had no luck.

-Greg

 

Glad to hear you got the belt sorted. I’ve never had a problem with routing the other way, but at least it seems like the change was free and did the trick. I’ll keep that in mind if it ever becomes a problem.

I would check the wheel for runout. If it is moving back and forth next to the sensor it will occasionally drop out. I spun the engine over by hand to check and correct. Also check that your RPM isn’t falling too low at idle. Before I reset the idle, it would sometimes idle at 550 or so, which would cause the sensor to record an error, but not actually lose signal.

 

Reset the idle? I'm having an issue right now where the idle will fall very low and the truck will stall when I'm coming to a full stop. I have a new cam installed and the tune on the GM ECU is from a 2004 GTO so I figured that I just need a custom tune to sort this out. I was also thinking of adjusting the idle manually by using the throttle wire and screws. So just curious what route you went to adjust your idle. Thanks for the help!

 

With HPTuners, you can set the idle to a target value. Stock is something like 600rpm most of the time. I set mine for 750rpm. Engine seems a lot happier there. With any cam with a lope, I would set it to 750 minimum. I'd say you should definitely look at a tune if you have a cam. I wouldn't bother playing with the throttle wire / screws - a tuner can set the idle higher with a couple of clicks. If you are stalling when coming to a stop, you probably need to check your VSS settings as well.

 

Guys that have completed the swap: was the extra power/reliability worth the money and time?

 

Ask me after 10k miles haha. I'm confident the reliability will be worth it in the end. Not really an issue with the swap but could sway some from choosing the LM4 over the LM7 as I might have an oil leak on my rear main seal. I went the extra mile and rebuilt my junkyard sourced engine and might have missed something with the rear seal. Very light leak but apparently LM4 engines are quite porous and might need additional RTV sealant around the back seal.

 

I did the same thing.. The harmonic chopper wheel was a little out of round on mine too. I manually spun the engine with a socket and worked to bend the wheel so it was as straight as I could make it in relation to the relocated crank sensor. I also had the M & S flashing lights every few starts, but mine was due to my XYZ switch needing to be cleaned.

 

I didn't tune this but ye's it's falling below 550rpm on various occasions. I'm not sure how much learning this system will do but right now when starting it needs to be given a little throttle input and kept alive for 5 or so seconds. Maybe this is a culprit. I'll check runout too today.

I believe my XYZ switch is working correctly. I'm curious, is the crank position error putting your vehicles into limp mode as well? Or is that XYZ related only? I am getting limp mode with the M&S light which comes on every few starts. Once it comes on it comes on even when the vehicle is not running but ignition is on. My rear wiper does come on so I know the XYZ switch mostly works but perhaps it has momentary issues I wouldn't spot.

 

Nope not even close.

You're asking about a Land Rover in regards to power/reliability/time/money?
Buy a Jeep Wrangler. Or a Toyota 4Runner or....well pretty much anything but a Discovery. LOL

In a year I'll be able to answer better how I feel about this swap. There's nothing logical about owning this vehicle much less putting money into it though.

I too have a leak somewhere from the back, either main seal or the sensor for oil pressure that we tapped. I HOPE it's not main seal...... Mine is enough that I'd consider it to be too much to daily drive. I also have the aluminum LM4 instead of the LM7.

 

That’s interesting about the rear main. I thought the rear main seal covers were the same between all of Gen 3/4 LS engines regardless of the block material. I guess the block along the sealing surface could be more porous. Of course it decided to leak oil once it was in a Land Rover.
The M&S (limp mode) can be caused by a bunch of issues. Crankshaft, XYZ, low battery, etc. Somewhere in the RAVE it lists all the ways — there’s a lot. I think if you can see all the gears in the cluster, like PRND321 when you move the shifter, then the XYZ is good. If you put it into one gear and its blank, then the XYZ has a problem.