ryan95i4 Posted June 23, 2012 Share Posted June 23, 2012 These were near the AFM connection on the harness, just curious what these originally went to cold start injector maybe? Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted June 23, 2012 Share Posted June 23, 2012 (edited) vacuum pump/EGR/A/C(idle kickup) controller. Question to be asked is: Is this device ECCS(ECU) controlled or controlled through external sources? I am curious, because ECCS control means that it can be retained in a swap easily for smog compliance. Edited June 23, 2012 by rayaapp2 Quote Link to comment Share on other sites More sharing options...
ryan95i4 Posted June 23, 2012 Author Share Posted June 23, 2012 Thanks, makes sense since that has been removed from my car Quote Link to comment Share on other sites More sharing options...
rejracer Posted June 24, 2012 Share Posted June 24, 2012 Ray, Both of those devices are controlled by the ECU. I just went through my L28ET swap. My advice, keep both of them, EGR is a good system that does not hurt performance. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted June 25, 2012 Share Posted June 25, 2012 (edited) Ray, Both of those devices are controlled by the ECU. I just went through my L28ET swap. My advice, keep both of them, EGR is a good system that does not hurt performance. MWHAHAHAHA... there was a reason I asked: MPG hike at cruise. I cannot remember if I need the AAC valve still. I kind of doubt it, but I will confirm first. My next issue is figuring out if the Z31 ECCS will also control the EGR system. So Im off to look into that. Edited June 25, 2012 by rayaapp2 Quote Link to comment Share on other sites More sharing options...
rejracer Posted July 3, 2012 Share Posted July 3, 2012 (edited) AAC valve is what controls the idle speed. This system only works when the throttle switch is closed. The other device, the air regulator can be done away with. What do you mean by MPG hike at cruise? EDIT: The other device shown in the pic is the EGR vacuum modulator. I was referring to the other device on the intake manifold that controls air flow into the manifold. Edited July 4, 2012 by rejracer Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted July 5, 2012 Share Posted July 5, 2012 (edited) A working EGR will allow the engine to run more timing at cruising speeds. Edited July 5, 2012 by HowlerMonkey Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted July 6, 2012 Share Posted July 6, 2012 EGR allows leaner AFR's at cruise. Chrysler being the biggest proponent of this implementation in past years off the top of my head. Just one of the reasons why EGR was implemented. I believe there are posts covering this information in depth on this site as well if you want to learn more. In my past turbo swaps I do away with the AAC and EGR but retain the Air Regulator on the stock ECCS system. Though I admit I have not figured out the complete function of the AAC as there seems to be an idle kickup separate for the A/C system. I am curious as to when the AAC is commanded to open and closed. Quote Link to comment Share on other sites More sharing options...
rejracer Posted July 8, 2012 Share Posted July 8, 2012 Ray, The AAC is controlled by the ECU to control the idle speed. To my knowledge it's not a on/off device as it controls idle speed in a variety of conditions. It only operates when the throttle switch on the throttle body senses the throttle plate is closed. The system and how to adjust it is described fairly well in the FSM. According to the FSM the ECU controls idle speed based on CHT, A/C request, Engine RPM, Throttle valve switch and neutral relay (auto only). There is a chart in the FSM describing what each sensor reading does to the idle speed at the ECU's command. The air regulator on the other hand is fully open when cold and the internal heater element causes a bi metal spring to close it as it warms up. If I were to do away with one of the devices it would be the air regulator. I would keep the AAC system. Idle control seems to work well on the car. I am thinking of doing away with the Air regulator, pop off valve, and the blow off valve. That would clean up the plumbing on top of the manifold quite a bit without any significant downside. I will have to plug the air regulator and run it for a few days to see if I like the cold start behavior. As far as the blow off valve, is concerned I would go with a more modern style that vents boost from before the throttle plate to just before the turbo. The stock system is annoying in how long it takes for the engine rpms to fall off after getting into boost. Quote Link to comment Share on other sites More sharing options...
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