LS Swap Accelerator Pedal Problem
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From: Red Deer, AB
LS Swap Accelerator Pedal Problem 
Our 1963 GMC with an LS engine installed
Where we started a year and a half ago.
My son and I are doing our first LS swap in a 1963 GMC we picked up from a friend by putting a 5.3L Vortec we pulled from a 2004 Chevy Silverado. We've been working on it for about a year and a half, and a couple of weeks ago, we actually got it to turn over. The problem is that when it starts, it idles above 3000 RPM and climbs up in stages until we shut it off. Using our basic OBII reader, we've traced this back to the accelerator pedal, which doesn't register any change when we press the pedal down.
My son's really excited to see the truck move (although, as you can see from the photos, we won't be going far without body panels or a windshield!) But, this is beyond me. I was hoping someone might have some experience to share ...
Our setup goes like this:
Engine: 5.3L Vortec that came out of a 2004 Silverado
Throttle body: Is drive-by-wire, and came out of the donor truck
ECM: Came from Painless Wiring (because they don't make a wiring harness for our original "blue/green" version)
Tac Module and Pedal Assembly: We've tried two of these: one marked TMDI-160A1 (from a similar year of the donor) and one marked TMDI-160E1 (which we were hoping to use because it's adjustable). Neither one registers anything when plugged in.
If anyone can help us figure this out, we'd be grateful.
Our 1963 GMC with an LS engine installed
Where we started a year and a half ago.
My son and I are doing our first LS swap in a 1963 GMC we picked up from a friend by putting a 5.3L Vortec we pulled from a 2004 Chevy Silverado. We've been working on it for about a year and a half, and a couple of weeks ago, we actually got it to turn over. The problem is that when it starts, it idles above 3000 RPM and climbs up in stages until we shut it off. Using our basic OBII reader, we've traced this back to the accelerator pedal, which doesn't register any change when we press the pedal down.
My son's really excited to see the truck move (although, as you can see from the photos, we won't be going far without body panels or a windshield!) But, this is beyond me. I was hoping someone might have some experience to share ...
Our setup goes like this:
Engine: 5.3L Vortec that came out of a 2004 Silverado
Throttle body: Is drive-by-wire, and came out of the donor truck
ECM: Came from Painless Wiring (because they don't make a wiring harness for our original "blue/green" version)
Tac Module and Pedal Assembly: We've tried two of these: one marked TMDI-160A1 (from a similar year of the donor) and one marked TMDI-160E1 (which we were hoping to use because it's adjustable). Neither one registers anything when plugged in.
If anyone can help us figure this out, we'd be grateful.
Andrew
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Joined: Aug 2010
Posts: 7,323
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From: Ann Arbor, MI
My son and I are doing our first LS swap in a 1963 GMC we picked up from a friend by putting a 5.3L Vortec we pulled from a 2004 Chevy Silverado. We've been working on it for about a year and a half, and a couple of weeks ago, we actually got it to turn over. The problem is that when it starts, it idles above 3000 RPM and climbs up in stages until we shut it off. Using our basic OBII reader, we've traced this back to the accelerator pedal, which doesn't register any change when we press the pedal down.
My son's really excited to see the truck move (although, as you can see from the photos, we won't be going far without body panels or a windshield!) But, this is beyond me. I was hoping someone might have some experience to share ...
Our setup goes like this:
Engine: 5.3L Vortec that came out of a 2004 Silverado
Throttle body: Is drive-by-wire, and came out of the donor truck
ECM: Came from Painless Wiring (because they don't make a wiring harness for our original "blue/green" version)
Tac Module and Pedal Assembly: We've tried two of these: one marked TMDI-160A1 (from a similar year of the donor) and one marked TMDI-160E1 (which we were hoping to use because it's adjustable). Neither one registers anything when plugged in.
If anyone can help us figure this out, we'd be grateful.
My son's really excited to see the truck move (although, as you can see from the photos, we won't be going far without body panels or a windshield!) But, this is beyond me. I was hoping someone might have some experience to share ...
Our setup goes like this:
Engine: 5.3L Vortec that came out of a 2004 Silverado
Throttle body: Is drive-by-wire, and came out of the donor truck
ECM: Came from Painless Wiring (because they don't make a wiring harness for our original "blue/green" version)
Tac Module and Pedal Assembly: We've tried two of these: one marked TMDI-160A1 (from a similar year of the donor) and one marked TMDI-160E1 (which we were hoping to use because it's adjustable). Neither one registers anything when plugged in.
If anyone can help us figure this out, we'd be grateful.
FYI - I have recommended buying DBW Blue/Green wiring harnesses on ebay because they have worked for me on several swaps. The "higher" priced ones around $180 have quality connectors. A member took my suggestion 2 weeks ago, but wasn't entirely happy with the harness; while quality was very good, he made continuity checks before installing it and claimed several mistakes. It also came with newer EV6 injector connectors and I think we needed EV1. Earlier someone reported buying a harness from Jegs ($500?) and it had the coils and/or injectors labeled wrong. (Makes me think its just an Chinese/Ebay harness doubled in price.)
In short, please tell us:
The part and service numbers on the ECM/PCM.
What wiring harness this is.
Part number on the pedal. Try to use the pedal and TAC that came from the donor vehicle.
What codes your OBD2 scanner/reader is giving. If this is just some $40 reader, you may need to upgrade to something better.
