Golka

Yeah the AEM was the previous owners choice, I'm not opposed to going mega squirt if I end up having to but I'm not sure how hard it is to make the switch, and I'm still hanging onto hope that I can figure this out in its current configuration

Golka

Did some digging in the boxes and boxes of parts and binders of receipts and manuals documenting the build that I got from the previous owner, and I came upon the installation and operators manual for the AEM, WOOOT! So I've learned a lot reading that and without messing with the tune at all I hooked up the laptop and began to explore the current tune to get a better understanding of it. The wires all match up with the wiring diagram, all the grounds are good so I think I can rule out any connectivity issues with the EMS. Upon cranking the engine I'm getting good readings from both the CAS and pulse on all four injectors, so the EMS is doing its job and I can assume I still have spark and no fuel as it will start with a spritz of starting fluid then promptly die. I've been assuming the fuel pump is good to go because I can hear it running and feel fuel running through the lines in the engine bay. My question is, say the fuel pump was running but was going bad or somehow had lost pressure, would insufficient fuel pressure cause the injectors not to fire? Fuel pressure regulator is brand new and the fuel pump/filter are all I haven't looked into yet since I've been assuming the problem was elsewhere.

Golka

I've ordered an inline fuel/oil pressure gauge, it'll be nice to have one lying around anyway. I'll update if fuel pressure seems unusual. Does anyone know what it should be at after priming?

Golka

So it's holding 45psi fuel pressure on the feed line when the key is on and fuel pump is running. Pretty sure that means fuel pump is all good. 0 psi when key is off. Back to the drawing board. Only reason I want to believe it's something simple and electrical is because it was running perfectly when I got it and I haven't touched the tune. Don't see how the tune could suddenly be a problem when I haven't changed anything mechanically. I've still got awhile before miata season up here so I'm not giving up yet, but if winter starts drawing to a close I may end up just dropping my tax return and finding someone that can figure it out for me 😑

Braineack

iTrader: (62)

ITS YOUR TUNE. ITS YOUR ECU. ITS THE TUNE ON YOUR ECU. FIX YOUR TUNE. IT'S NOTHING MECHANICAL!!!!!!!!!!!!!!!

Golka

I'm sure you're correct and I apologize for frustrating everyone who's trying to help. Looks like the nearest place I can go is the shop in Minneapolis that originally tuned the ECU when it went in the car. I was just trying to avoid the 17 hour drive there and back in my gas guzzling Tahoe with a miata in tow. I'll be make a call to them tomorrow and try to set something up.
But just so I don't sound dumb, how is it that a tune can be good for years and suddenly cause the car not to start when nothing has changed mechanically?

Schroedinger

Yeah, that sucks- sorry. As Brain said, I don’t think anyone here speaks AEM, Megasquirt is the native language here. Have you tried calling the tuner in MN to see if he’ll check the logs for you?