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Discussion Starter · #282 ·
Now onto my huge headache. I got the engine all tied up and ready to run. Three fire extinguishers on hand, batteries fully charged, new fluids, sparkplugs, and HPTuners all ready to go. Turn the key and it won't fire??? Checking everything over and noticed I didn't put the spark plug boots back on, they were just tucked into the manifolds, pretty funny actually.

Try again, fires right up nicely and dies after two seconds.....again, same thing....Right off I figured Speartech forgot to turn of the VATS (vehicle anti-theft) or the Start Diagnostics, because that's exactly how it should act if they're on, double checked the tune and it was fine. Confused now, next I figured it must be the Viper remote start/alarm stuff, so here we go, tearing into all the under dash wiring, pulling apart bundles etc. This thing has about 40 wires going into it and the customer support is nil unless you are a professional installer. It's doable but very complicated, I don't suggest it lol. I was sure it was something I did, I retraced every wire looking for a problem and couldn't find anything. I finally got through to a guy in tech support and he assured me that if it fires, there system will NOT shut it down due to liabilities. So on to the next, I hooked up HPTuners and did an in depth scan of everything I could think of, I got a collection of 2 second runs, hard to notice anything but got something.

I'm running a PWM fuel pump (no return lines) and a Fuel Pump Control Module that run off a Fuel Pressure Sensor and it adjusts flow according to demand. Well in Canbus systems you have a 5volt reference, a ground (or low voltage), and a signal wire for the sensor. I noticed that I wasn't getting a signal voltage to the ECM, Eureka!!!! I tested my wiring, and even jumped the wire directly from 5v to signal and it still wasn't getting it in the ECM, this really sucks cause after looking through GM's test procedure it concludes the ECM pin is dead, new ECM required, F!!!!!! I thought if I just disconnect the MAF I could force the engine to run in Open Loop just to see if it was the tune or the ECM. In hindsight this is funny because it wouldn't start this way when I tried it once, later I found out you need to do 2-3 attempts to force it. This was going on for a couple of weeks so I just ordered another one and figured I'd just copy my tune to it. It showed up and what I didn't expect is when you buy new there is no operating system on it, it has to be downloaded and licensed in the vehicle and then I could copy over my tune. Well that would involve towing it down there, paying an unbelievable price for a 10 minute download, and a tow home.

Sorry, this is getting as long as Stairway To Heaven. I decided I would try to get a hold of Mitch at Swaptime to see if he could bench tune it (Speartech can't). He has got to be the most knowledgeable and helpful guy around when it comes to Gen 5 engines, as well as all the other LS's. We got talking and he wanted to see the scans. I hooked everything up and he got on to my computer remotely from Vegas and started searching through it. Now he was stumped lol. He poked around for about 15 minutes when he came across the MAF (Mass Air Flow sensor on the intake tube), they had values tuned in there ranging from 3-5 when they should have been 150-300 kind of range. So the pump would prime, start the truck, and immediately cut fuel because it thinks the air is pretty much blocked and it doesn't want to dump raw fuel into the engine. The guys a gene-us (see what I did there lol). He copied one of the MAF tunes he had, not perfect but close enough and guess what, started right up. Runs a little rough until it's fine tuned but it's running, and oh yeah, when I disconnect the MAF it runs great (just burns more gas).

I have to put in a Plug for Mitch at Swaptime. He puts out tons of videos on You-tube to help people and he is totally developing these swaps to run just as the factory intended. He has helped me numerous times during this build and has always figured out my problems. I'd like to also point out, the only thing I have bought from him is his Muscle Car Module (for tap shift, reverse lights, tow mode, and AC idle up) and in return his help has been priceless. I regret not starting out with him on my wiring harness and tuning and would highly recommend him to anyone planning a swap.

Now I have to figure out how to post a video????
Sean
 

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WOw.. What a ride.. Super happy you got it running! This write up is biblical for those of us Gen V builders. I will definitely reach out to mitch and send him some business.
Were the maf sttings incorrect from speartech? Incorrect meaning, is 150-300 factory? and some how they misprogrammed? I wont be gettimng my harness from them for a while, but would at least mention it to them before they ship it
 

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Discussion Starter · #284 ·
Yeah, they screwed up. They said they ran it on a test engine before shipping but I'm not buying that at all unless they run it with the MAF unplugged, 100% their fault. I bought a new ECM for $300 and they were going to charge me another $500 to program it. If anyone needs a new ECM I can't return it either.

There's a lot of similarities to the LS but there is also a lot to learn about the differences and not much information out there. Everyone seems to want a work around instead of getting it to run as it was meant to. Pretty excited to try it out, talking to Mitch he said the L83 is the same as an LS3 but with a little more torque down low. He's also getting the turbo 4 cylinder going now as well ("the L3B's 310 horsepower and 348 pound-feet of torque").

I think I just finished the last of my wiring but I don't want to jinx it by saying that lol.

Sean
 

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My MAF was doing a similar thing. It ran perfect when I had the air intake mocked up with no turns. As soon as I put a 90 degree turn between the air filter and the MAF, it wouldn't start fully, or it would start and sputter and die in 10 seconds. I went to an LS forum and sure enough, tons of guys had the same problem. They said the MAF reads differently on the convex vs the concave side of the intake. So I switched it to the convex side and BOOM! works perfectly.

I liked your investigation more. I have no idea how to diagnose most of these problems, or even run the tools for diagnosis. I've got a lot of reading to do. So much for me to learn!
 

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Discussion Starter · #286 ·
I only know enough to be dangerous, HPTuners can do more than I'll ever attempt. It is cheaper than buying a good scan tool at $400, if you want to make changes you buy credits for $50 each and license it, mine cost 4 credits. Also if you find a guy like Mitch he can do it remotely over the internet. You download Anydesk and he can take over your computer live in real time. I just use a cheap Windows computer that doesn't have anything else on it so no worries about getting hacked.

Sean
 

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Hey Sean - thanks for sharing your experience, Ive just started a 90 300tdi conversion, I thought i was fitting an L83 and 6L80, turns out the dealer sent me an L84 by mistake. So my flex-plate on the L84 doesn't match the 6L80. did you have the same issue with your flex plate?
 

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Discussion Starter · #290 ·
Just finishing up the dash with leather. I used actual cow hide instead of the automotive stuff, looked too much like vinyl to me. The cubby, tray and speaker bar have proven to be the hardest and most time consuming pieces, had to work from the bottom up in small sections.

Sean
 

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Discussion Starter · #294 ·
It's been hiding out in my moms garage. I decided to sell my house and move close to my sons school, it sold to a friend of a friend before I even listed it. They were expecting a baby so I gave them a quick closing and had to get out of there and I offered to make sure it was as good as new......painting, repairing, touch-ups etc, the offer they gave me was nuts.

I wanted an acreage but the market was getting out of control so I ended up buying a house right around the corner from his school which has been great for him being close to friends etc. The basement was unfinished with 9' ceilings which is great but I had to do electrical, insulation, and drywall in both the garage and basement and then we turned it into a play area. Built a big climbing wall, 1/4 pipes, gymnastics equipment, and now we're building a RC crawler course for the Traxxas trucks lol.

The down side was I went from my shop to a two car garage but buying a house with a third bay was about $300000 more which is nuts, especially given it's only another 8' wider. So I built an 8'x20' shed for cold storage, sold a bunch of stuff and rented out a storage bay. Just have to do the drywall taping and add the furnace and I hope to get the Defender back here to finish up.

I did get to do a short drive around the block when I loaded it up onto the trailer, actually the first time I got to get a look at the front end.

The torque that engine has is quite amazing, I thought I had it in low gear, wow.

Sean

 

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Life , it gets in the way of ...life. So glad you got to drive it up the ramps and see it in the daylight off the lift! Looking super cool. That friggin bumper is Nuts! I finally got back to work and will hopfully get my engine in this winter. I have decided to remove all the DOD stuff. So, cam, lifters and a few other items will get replaced. Only going for simple stage one style cam. not sure Texas speed or Brian Tooley yet. Anyone with thoughts or advice which is company is a better way to go..(2017-L83) Please chime in.
 

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It's been awesome following your build. You have had to make some tough choices, but I'm sure you're doing it all right. Here's wishing you happiness in your current situation, and blessings in the future for you and your family.
 
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