Herbst

I recently tried to hook up my AEM 30-2400 boost solenoid to my self built MS3x following Westfields guide. I've tried using the boost output as well as the idle output with a flyback diode and had the same results. Nothing happens at all in closed loop boost control, and upon entering open loop the car beings running super rich based on the boost duty cycle. Higher duty cycle for the boost controller yields more fuel being dumped in. I've tried different frequencies as well with the same results. The solenoid itself runs fine on the 30-4350 tru boost gauge, and the solenoid has a resistance of 10 ohms. I keep thinking I must have messed up the wiring, but I cant figure out where. So far the car runs great and has no problems running on spring pressure, the only thing I cant get to work right is the boost controller. Its a tial sport external wastegate with a 10lb spring. Any help would be greatly appreciated as I haven't found a similar situation online.

Matt Cramer

First, make sure it turns off and on OK in output test mode.

Herbst

It works great in output test mode. It's only when the car is running that I have issues. I have the jumper from the c side of d1 to the s12 pin on the mainboard. I'm also running it with a flyback diode. I figured I might have had a short between the idle pin and injector pin (ms3x pin10) but upon inspection it looked fine. I just can't figure out why the injectors increase their duty cycle like crazy when I turn on boost control.

Herbst

Here is a datalog when open loop boost control is turned on. One is on low frequency mode while the other is on mid. I can actively hear the solenoid running, and i have the boost duty cycle at 50%

Matt Cramer

Does the injector DC increase only if boost control is turned on in software, or does it change depending on whether the solenoid is receiving power regardless of TunerStudio settings?

Herbst

It increases only if the boost control is on in software. When boost control is off I leave the solenoid hooked up and the car runs fine. I can also turn on boost control and have the boost solenoid disconnected from the 12V switched source and it runs fine. But the moment I reconnect the solenoid, it starts running poorly. When I look at the data log, its like boost control messes up everything. Duty Cycle, PW, and even spark advance all look like the have a ton of noise and have higher values than normal. I was resoldering some wires today trying to find a solution, and I believe I accidentally disconnected the main power to the board, but when I plugged it in, the ecu powered on through the boost output, and even started and ran like normal. And when I unplugged the solenoid, or tried to test the boost output, the ecu would turn off. I could make this happen with both the boost and idle outputs. I resoldered the main power and reconnected it and the car went back to normal, except the boost control is still acting the same way as before. I just dont see how any of this is possible, as I thought the mid current outputs were separate from injector and spark outputs. And it makes no sense to me how I can power the ecu through the idle/boost. I obviously messed something up, but I cant seem to figure it out. This has absolutely frustrated me as the car runs perfectly without the solenoid connected , but the moment I connect the 12V with boost control on, everything goes haywire.

Herbst

I did a couple more test, and with the boost controller at 50% duty, it is drawing 0.5A. And I put a 10 ohmn resistor in series with the solenoid which dropped it to 0.2A, but the car still acts the same. For now I'm just going to run the solenoid off the tru boost gauge until I can figure this out. My gut tells me I wired something wrong or forgot to wire something, I built it with Westfields guide, and the expander board didnt even require a lot of modification so I cant seem to pinpoint the problem. Next time I have it out of the car, I may just remove the idle output completely and just run it off the boost output and see if that helps.