Time and time again, the GSL-SE owner finds the need to remove the ACV and air pump to install racing beat headers. That person has become me, and I have a whole host of issues that have occurred since the header install. I have completely removed the air pump and ACV, and put on the appropriate blockoff plates. I installed racing beat headers and presilencer and have replaced the 5th/6th port actuators for electronic ones.

The issues that I am having is that my GSL-SE will start, but it won't idle. It dies immediately after starting, unless I put my foot on the accelerator and keep it alive. I know these are similar symptoms to other owners but I have tried all of the solutions on the forum and still have not found the issue yet. If anyone has any tips or tricks on how to diagnose this, please let me know. All help is appreciated.

 

Your SE won't idle because you've introduced a significant vacuum leak that's allowing air to bypass the Air Flow Meter. The likely cause is your ACV block-offs plate(s) that aren't correct for the SE. Specifically, if not SE block plate, there will be a large slot left uncovered under the ACV mount that allows air into the system. The reason why you can pump the accelerator and get it to idle is that sudden acceleration fools the engine into running momentarily rich, which allows it to run at all.

That said, the SE will run just fine with the ACV installed, a RB Header and the Air Pump either installed - with the drive belt removed - or Air Pump removed entirely. There is no negative interaction between these parts, as long as the ACV is still installed, sealed to the Lower Intake Manifold properly, and not leaking air. The RB exhaust doesn't care about the ACV and works just fine in conjunction with it.

Secondly, you commented that your '6'-ports have been replaced. These also have gaskets which seal the Feedback Sensing Tube air from the exhaust system acupressure to operate the Actuators. If these have been removed, or replaced with some other system, you'll need to be sure they're not a source of air leaks into the intake system. Are you running the correct SE RB header with a Pre-Silencer equipped with the back pressure sensing tube? It should also have an O2 sensor bung which allows the SE ECU to operate in closed-loop mode during certain driving conditions (*steady throttle, 5th gear, and cruise control engaged).

Let us know what you're running, and installation of the ACV will likely fix your idle issue. The rest is simply confirming that you have no other air leaks in the intake system.

 

Hi LongDuck, appreciate the reply.

I believe the entire actuator system is closed loop, meaning that after the exhaust tap, that system is independent of the intake. I removed that entire system, and am running a 12a presilencer on my -SE so that I don't have an exhaust tap. I have an electronic 5th/6th port actuator kit from JAFA engineering, which removes the need for the stock actuators. They were broken on my car and weren't operating properly.

I will actually go change the blockoff plate that I received. I got one from Atkins and RB, but I used the Atkins one because I got their parts about 2 months earlier. This is probably the issue, as I'm using their 81-92 blockoff plate not designed for the -SE. I will also check for leaks in the intake system. The O2 sensor is new and I installed it with the header.

Below are a list of mods to the engine bay that may affect operation:
-Electronic 5th/6th port actuators
-FPD removal
-ACV removal
-Air pump removal

Thank you for your prompt reply and if you have any other suggestions, please feel free to let me know.

 

Hang onto those old parts! More than one driver has shown up here after removing any number of parts and threw them away, only to discover they were needed.

On the blocking plate, when you go to remove it, inspect the edges and look for gaps. There will likely be a slot exposed on the bottom that the ACV uses for air injection into the exhaust. I've been running my stock ACV with a RB 13b header for decades now with zero issues. The ACV isn't a problem if you leave it in place.

I'm curious about your electronic auxiliary port actuators. Have any pics? Experience on when they open and how well they work for controlling intake air stack velocity?

The stock Mazda system for SE uses exhaust back pressure because it's driven by engine load, not by RPM thresholds. This is preferable to get a nice smooth power curve for what little torque there is, which the SE is known to produce.

 

I think I'll just plug the original ACV back in like you suggested - that way I don't have more ambiguous unplugged connectors.

As for the electronic actuators, I can't really speak to the quality of their manufacture or operation. The car has not ran reliably since they were installed. I can send some more pictures over the weekend when I go back home to work on the car. The only reason I went for these is because the original actuators were failing and the entire exhaust was due for a refresh. I wanted to go for these actuators because these seem to have cheap commercially available parts. More information is available on this website: Jafa Engineering

I'll keep the spare parts for now, but if anyone needs a spare air pump or exhaust manifold, feel free to hit me up.

 

Quick update - Figured out all my problems.

I tore down the entire intake and found that I had missed some really stubborn gasket on the lower intake side - My gasket split into a million pieces when I initially took the intake off. I did clean the surface off to what I thought was an acceptable level but I guess I missed a few spots.

The electronic actuators are functioning now and my dad took the car for a drive. We hit 60mph, which is a first for the car in 20+ years. I will link some pictures of the actuators as requested.


Thank you LongDuck for the advice. Even if the ACV plate wasn't the issue, the line of thinking with the unmetered air was ultimately what saved me.