Atlas I6 control

**ericjon262** · 09-25-2013

I recently purchased a 1970 GMC truck, that I would eventually like to swap an Atlas 4.2 I6 from a Envoy into. the only problem I have with the atlas is the DBW throttle control(I like cables!). is there any way around the DBW that allows me to keep the VVT active?

I'd rather this thread not turn into a debate on DBC v. DBW, I don't like DBW, we can leave it at that!

-Eric

**RobertISaar** · 09-26-2013

find a cable throttle that works and get something for standalone VVT control?

i want to say there is an option out there that the megasquirt crowd uses, but i have no idea what it is called.

**Six_Shooter** · 09-26-2013

If it's anything like other DBW systems it should be a pretty straight forward swap, since there are in some systems still a TPS sensor, and the DBW is basically a stand alone system. I don't know if this applies to the Atlas I6 though.

I would just go DBW and be done with it, no need to complicate a swap more than it already will be. I'm actually looking at changing my cable system to DBW, to help clean up the engine bay. :)

**ericjon262** · 09-26-2013

the problem isn't always that simple though, there's another piece to the puzzle outside of a TPS signal. IAC is also controled be the TB in DBW apps, and most of the later PCMs that utilize DBW don't have a IAC motor circuit. I'll do DBW if I have to to keep VVT, but I just personally don't like it. I was hoping someone might be aware of a OBD2 option to keep VVT and ditch DBW, mainly because I have all of the obd2 tuning stuff already, and would rather not have to re-invest in another system.

**Fast355** · 09-26-2013

Originally Posted by ericjon262

the problem isn't always that simple though, there's another piece to the puzzle outside of a TPS signal. IAC is also controled be the TB in DBW apps, and most of the later PCMs that utilize DBW don't have a IAC motor circuit. I'll do DBW if I have to to keep VVT, but I just personally don't like it. I was hoping someone might be aware of a OBD2 option to keep VVT and ditch DBW, mainly because I have all of the obd2 tuning stuff already, and would rather not have to re-invest in another system.

ALL Atlas engines that I know of were DBW. That being said its not the same as say a LS1 where both DBW and DBC were used.

**ericjon262** · 09-26-2013

well, I'm not afraid of running it off of a non-Atlas PCM, and I think just about any V6 PCM could run it, main concern is the VVT...

**EagleMark** · 09-26-2013

Why complicate it? Just run the PCM that came with the DBW and VVT engine and adjust so it feels like DBC...

**ericjon262** · 09-26-2013

lol, I complicate everything...

**ericjon262** · 09-26-2013

This is going to sound totally silly... and it is... but the newer vehicles get, the less control the driver truly has, the throttle is one place I'd rather not give up total control.

say what you want, but that's me. if I have no other option, I'll do DBW, but it'll be close to a last resort.

**ericjon262** · 09-29-2013

I guess before I even think about a swap, I should fix the PO's "wiring"...

**ericjon262** · 09-29-2013

presenting plug number 4

and plug number 6

looks like I have a reason to start on the engine swap.

**ericjon262** · 10-02-2013

well, I'm thinking it'll probably be best to go ahead and convert to DBW, I don't want to, but it's really the only practical solution. anyone have a lead on wiring diagrams for a 2008-09 GMC Envoy 4.2 2wd?

**bobdec** · 10-02-2013

Try here... http://gmtnation.com/f23/need-servic...them-here-371/ login and PW are in the post.. in my 07 Envoy DBW has a pair of sensors on throttle pedal one 0-5V and the other 5-0 volts for redundancy and backup. As stated the TB is used for idle air control (no IAC valve). They seem to have done a good job , idle speed is consistent in N or D and with AC cycling on/off it stays rock solid at the same RPM. In '08 the GM 360 line (Trailblazer, Envoy, etc) went from a PCM to an ECM and a TCM (Transmission control Module). Not sure how they interact together. How do you you plan on managing the 4.2.

**ericjon262** · 10-02-2013

Originally Posted by bobdec

Try here... http://gmtnation.com/f23/need-servic...them-here-371/ login and PW are in the post.. in my 07 Envoy DBW has a pair of sensors on throttle pedal one 0-5V and the other 5-0 volts for redundancy and backup. As stated the TB is used for idle air control (no IAC valve). They seem to have done a good job , idle speed is consistent in N or D and with AC cycling on/off it stays rock solid at the same RPM. In '08 the GM 360 line (Trailblazer, Envoy, etc) went from a PCM to an ECM and a TCM (Transmission control Module). Not sure how they interact together. How do you you plan on managing the 4.2.

Thanks for the link, that is extremely helpful!

**ericjon262** · 10-05-2013

Originally Posted by bobdec

Try here... http://gmtnation.com/f23/need-servic...them-here-371/ login and PW are in the post.. in my 07 Envoy DBW has a pair of sensors on throttle pedal one 0-5V and the other 5-0 volts for redundancy and backup. As stated the TB is used for idle air control (no IAC valve). They seem to have done a good job , idle speed is consistent in N or D and with AC cycling on/off it stays rock solid at the same RPM. In '08 the GM 360 line (Trailblazer, Envoy, etc) went from a PCM to an ECM and a TCM (Transmission control Module). Not sure how they interact together. How do you you plan on managing the 4.2.

just saw the bold text, I'm going to use a stock PCM/ECM/TCM and tune it with tunercat obd2.