CCLB dually #2

Supercharged111

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Stupid me repined C100. After that didn't work I had a serious derr moment. The interior diesel harness must run that signal over to the PCM and back to the cluster so I just need to loop those together and it'll be done. I'm a retard.
 

Supercharged111

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So there is a lot of wiring in the service manual. To keep things easy to follow, I’ll start out with what you have circled in that last photo. The sun was casting some nasty shadows, let me know if you can’t make anything out.

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So I can see here where to nab the VSS signal that makes its way through the firewall. What I can't see is what to hook it to to get it back to the instrument cluster. In the meantime, I need to unrepin C100. Good thing I didn't put the tools away just yet.
 

Supercharged111

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So, I forgot to grab the manual in my rush out the door on Friday. I’ve come up with a couple possibilities. In the convenience center, C9 is 4000PPM VSS. On the C100 Connector, C4 is VSS on Diesels, D4 for the gas jobs. I think this is where you might need to look.

VSS on the gassers comes straight from the PCM, whereas the diesels have a buffer like the older EFI. Hope this points you in the right direction.

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So the C4/D4 thing ended up being false. The big difference here is that the buffer lives inside the truck, under the PCM. The signals that pass through the firewall do so in the same places. The only real difference is that in a gasser Vortec, they're already conditioned. In a diesel, they're not. So the wire colors are different, but the function is the same. I imagine you'd deal with this swapping an LS into a TBI gasser as well. So after a few hours of chasing my tail, I finally got to try this: jumping the buffer's plug.

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Speedo works like a champ. Tomorrow I'll chop and splice the wires. Similar process for the SCV on the radio. @JSlezak83 the pin out you posted for C100 is incorrect. I googled it and found another posted on this site that was correct and it finally got me where I needed to be. I fact checked it with Mitchell once I suspected bad data was shooting me in the foot. It's all good, more of an FYI.
 

Supercharged111

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So I've ignored this thing since I parked it at my friend's place last November. I was on crutches for 10 weeks and about as soon as I was walking again, we had our 3rd baby. Today after work I swung out to take the truck for a spin and the CEL came on. Finally a clue! It was a P0404 which would explain the audible warm idle misfire and cold tip in hesitation. I wish I would have just unplugged it and retested. I think I'll try that before opening my wallet or cracking any bolts loose. It looks like my good 350 EGR valve won't work? I'm wondering about ohming the thing out too.
 

Supercharged111

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@Schurkey or anyone, do you have a procedure to ohm out the EGR valve? Damn things are $120 new, for that money I could tune it out and give this lump some more pep. I have a friend with a Snapon scanner that should have the bidirectional controls to be able to command it.
 

andy396

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@Schurkey or anyone, do you have a procedure to ohm out the EGR valve? Damn things are $120 new, for that money I could tune it out and give this lump some more pep. I have a friend with a Snapon scanner that should have the bidirectional controls to be able to command it.

HPTuners can command it. Are you positive EFILive can't?
 

Supercharged111

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Well I swapped in my 350 EGR and a 454 one I found in the junkyard and it's acting the same so that's fun. I finally got off my ass and welded some scraps together to get the muffler plumbed in. Here are the bits tacked.

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And welded together but not to the truck. A pie cut filled the gap nicely on the pipe on the right. Shorts and a t shirt don't fly when welding overhead, I forgot to pack pants and long sleeves today. I plan to burn these to the truck tomorrow and move it back over to my hangar now that I own it instead of rent.
 

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Supercharged111

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It's QUIET. I thought my other dually was quiet, but this thing is quiet quiet. No wonder the stock muffler gets such a bad rap for being restricted. I forgot to snap a pic before I got it off the lift today, but it went as quick as it should have clamping and zapping it all shut.
 
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