DBW to DBC

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LateOnTheBrakes

5.3-Swapped 86 CUCV
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I am thinking of converting back to the drive by cable setup for my LS swap. I got the blue/red PCM and cable throttle body when I was at the junkyard, before I learned how to make the drive by wire setup work.

The problem I am having with the DBW setup is it stalls when I am decelerating and push in the clutch with my SM465. I have the Dakota Digital 8K pulse generator and my PCM was programmed to work with 8K on the VSS. It still dies routinely.

What cable are you guys using for the DBC setups? Can you use a Vortec cable with the stock K30 pedal? Any troubleshooting I can do to keep the DBW setup?
 

Madhorn

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I am using the stock DBW set up in my 77. The issue I have is when I have the AC on, the idle dips a bit when pulling up to a light with the clutch in. Then when I shut the AC off the Idle rpm wants to jump Up a bit. Still working on the tune. The idle air flow may need to be increased along with base idle.
 

Madhorn

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The other thing to consider is not all genIII PCMs support that conversation. Check out LT1swap for details.
 

LateOnTheBrakes

5.3-Swapped 86 CUCV
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The other thing to consider is not all genIII PCMs support that conversation. Check out LT1swap for details.

Yeah, I understand. If I make the swap I would probably move to a Holley Terminator X standalone harness and PCM. The harness I modified is ugly as sin, but I wanted to use it at first to verify the engine runs. Now that I'm confident I put it together more or less correctly, I am ready to start investing more in it.
 

eskimomann209

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I used a cable from a c1500 I believe it was an 01. Had to modify the fire wall hole a bit ( Widen it). And use one of those cable stops in the pedal. Also used my stock 73 c10s pedal.
I actually used two stops for good measure.
 

Bextreme04

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I am thinking of converting back to the drive by cable setup for my LS swap. I got the blue/red PCM and cable throttle body when I was at the junkyard, before I learned how to make the drive by wire setup work.

The problem I am having with the DBW setup is it stalls when I am decelerating and push in the clutch with my SM465. I have the Dakota Digital 8K pulse generator and my PCM was programmed to work with 8K on the VSS. It still dies routinely.

What cable are you guys using for the DBC setups? Can you use a Vortec cable with the stock K30 pedal? Any troubleshooting I can do to keep the DBW setup?

Was the vehicle you pulled the PCM out of a manual? It sounds like you don't have the correct trans segment in it. What OS are you running? If you have an android you can buy an OBDX Pro Vt for $60 and then use the LS droid app to do any segment swaps you want for free. You can also use Tunerpro RT to change anything you need.
 

LateOnTheBrakes

5.3-Swapped 86 CUCV
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Oh, I know it doesn't have the right transmission. It was from a 2005 Suburban with a 4L60E. The transmission I have is an SM465. I had the PCM programmed to look for an 8K signal. I have a Dakota Digital 8K signal generator. It is still not working well.
 

Bextreme04

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Oh, I know it doesn't have the right transmission. It was from a 2005 Suburban with a 4L60E. The transmission I have is an SM465. I had the PCM programmed to look for an 8K signal. I have a Dakota Digital 8K signal generator. It is still not working well.

That's your problem then. You need to have the actual manual transmission segment. The VSS signal has nothing to do with it. There are different tables and settings for a manual transmission that requires the correct transmission segment to be there. Switching to DBC wont fix it at all. If you have 4x4, you should also make sure its a segment from a manual 4x4 so you have the right tables for low range. It's not that critical wit ha manual, since you don't have shift points that would need to change, but it will make a drivability difference.
 

LateOnTheBrakes

5.3-Swapped 86 CUCV
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That's not true. They specifically make the signal generator to let your PCM know when the vehicle is actually idling vs when it's moving. The LT1swap guy that removed VATS also set it to get the 8000 pulse signal. I guess I need to call and talk to him. I was hoping some folks here already had a similar issue and knew how to troubleshoot.

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