I believe it’s off by default, but in any case I would leave it be and let the EGO control adjust by a flat % until you feel more comfortable turning on what I call an advanced setting. FYI it’s always been off on mine.
Popping on "tip in"
- Thread starter Mavdaddy
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I believe it’s off by default, but in any case I would leave it be and let the EGO control adjust by a flat % until you feel more comfortable turning on what I call an advanced setting. FYI it’s always been off on mine.
Like Raymond said, don't overcomplicate the stuff. Some of us are long-time geeks and love to play with all the nuances and capabilities that are "outside the box."
You may find that you'll need bigger injectors with 15 lbs of boost on a 408. I'd suggest pulleying it down a bit while you work your way up the scale.
The VE and timing tables in the tune I sent are good through about 16 psi on my motor. I also have them scaled through 6000 rpms, so if you're revving higher, you'll eventually need to work that out, too. The transmission tune I sent will command shifts about 5500 rpms.
You may find that you'll need bigger injectors with 15 lbs of boost on a 408. I'd suggest pulleying it down a bit while you work your way up the scale.
The VE and timing tables in the tune I sent are good through about 16 psi on my motor. I also have them scaled through 6000 rpms, so if you're revving higher, you'll eventually need to work that out, too. The transmission tune I sent will command shifts about 5500 rpms.
Before the cam change, trim upgrade, and intercooler it normally ran about 17 lbs. boost with this pulley combination. Dyno days were the only time I ever got to see AFR and it was pretty fat and happy up to 6500 rpm. I attributed this to the fact that the FMU was pushing fuel pressure to over 85 psi. Now with this new set up the boost is down 2 lbs. Taking into account the fact that boost is a measurement of restriction not actual volume. I would have to assume a bigger cam, more efficient blower, and a cooler IAT adds up to more air/oxygen flowing through the motor. More oxygen needs more fuel. This sound about right?
If so maybe I really do need to consider a bigger injector. If an injector is "rated" at a certain flow rate I am sure that rate is estimated or proven at a specific pressure. Guess I should actually read the data you found for me and see what it says about that. Sorry. I have a tendency to think out loud and rant while I think.
The elevated fuel pressure worked to make the injector act much larger. It works, but it's not the best way to do things. The tuning becomes more convoluted, the injector behavior isn't predictable, etc.
Our injectors are rated to flow a certain amount at ~40 psi of absolute pressure difference between the rail and the tip of the injector. So, with the engine off, fuel pressure is set at ~40 psi (I set mine at 43 psi). When the engine is idling, fuel pressure drops from that set point so that the difference in pressure from the rail to the tip of the injector is still ~40 psi. When manifold pressure increases, say to 10 psi, the rail pressure raises to ~50 psi so that the difference across the injector is still ~40 psi. Thus the flow rate from the rail into the manifold is always controlled only by the change in injector pulsewidth, which is commanded by the ECU.
Using an FMU made sense when we were trying to convince computers that had no idea what boost was to do something they had no capability to do (I ran one for a long time). With these modern ECUs that "know" exactly what's going on, it's far better to tune the behavior rather than trying to force it by mechanical means.
You shouldn't need the boost retard, either.
Converting to sequential helps the injectors out a lot because they don't have to open and close multiple times per revolution, so you don't eat up a lot of duty cycle with the open/close time. So, they may be enough, but they'll be reaching their limit. But the ECU will tell you. One of the fields you can data log is duty cycle, which will make it easy to tell if you need more.
Our injectors are rated to flow a certain amount at ~40 psi of absolute pressure difference between the rail and the tip of the injector. So, with the engine off, fuel pressure is set at ~40 psi (I set mine at 43 psi). When the engine is idling, fuel pressure drops from that set point so that the difference in pressure from the rail to the tip of the injector is still ~40 psi. When manifold pressure increases, say to 10 psi, the rail pressure raises to ~50 psi so that the difference across the injector is still ~40 psi. Thus the flow rate from the rail into the manifold is always controlled only by the change in injector pulsewidth, which is commanded by the ECU.
Using an FMU made sense when we were trying to convince computers that had no idea what boost was to do something they had no capability to do (I ran one for a long time). With these modern ECUs that "know" exactly what's going on, it's far better to tune the behavior rather than trying to force it by mechanical means.
You shouldn't need the boost retard, either.
Converting to sequential helps the injectors out a lot because they don't have to open and close multiple times per revolution, so you don't eat up a lot of duty cycle with the open/close time. So, they may be enough, but they'll be reaching their limit. But the ECU will tell you. One of the fields you can data log is duty cycle, which will make it easy to tell if you need more.
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Wow... I set this thing up with that boost referenced regulator because I was told that was "the way to go". I just figured it was to do on a smaller scale what the FMU has been doing ("make the injector act much larger"). I never really considered that what I was really doing was adjusting fuel pressure the maintain a constant pressure above manifold pressure. This is good stuff. Man... I hate that I never really made that connection in my head. I knew this was the reason for a boost referenced fuel regulator on a blow through carb (over come the pressure increase to maintain fuel flow into the float bowls). Why didn't I see that same logic at work in fuel injection?
Aftermarket EFI is a lot to take in, one item where Megasquirt takes a hit is that there is sooooo much that it can do, however that's a double edged sword. Other EFI systems will give you a very limited interface which seems easier to setup, but might sacrifice features or functionality. Different people see value in different approaches.
Anyway, no need to beat yourself up you're learning! One thing I might suggest, and I am kinda going back on what I said, but the AFR Safety System can be very beneficial to have especially on boosted applications. I've run it on mine since day 1 it is very straight forward and fairly easy to setup. I don't mind helping on that if you want.
Well my worst fear has come true. I followed all of the instructions I can find to read, and the very first step has failed. My laptop will not communicate with the ECU.
I installed the drivers and connected the USB. My laptop detected the connection and installed the Comms port (COM3) as well as the Serial adapter. When I remove the USB and reinsert, it removes and reinstalls the driver, as expected.
When I open Tuner, it does not detect any ECU connected. I've tested all of the available ports and Baud rates. The default should be COM3 and 115200, which is still not communicating.
I've tried multiple USB ports on my laptop and replaced the USB cable, still no luck. I've removed and reinstalled the Tuner application, the drivers, rebooted, etc. I'm wondering if the serial adapter (3-pin) isn't working or if my ECU isn't responding to the external connection.
I installed the drivers and connected the USB. My laptop detected the connection and installed the Comms port (COM3) as well as the Serial adapter. When I remove the USB and reinsert, it removes and reinstalls the driver, as expected.
When I open Tuner, it does not detect any ECU connected. I've tested all of the available ports and Baud rates. The default should be COM3 and 115200, which is still not communicating.
I've tried multiple USB ports on my laptop and replaced the USB cable, still no luck. I've removed and reinstalled the Tuner application, the drivers, rebooted, etc. I'm wondering if the serial adapter (3-pin) isn't working or if my ECU isn't responding to the external connection.
I had same deal with expansion port and cable. Had to use the normal USB with it hanging half out into the engine compartment. I’m thinking the adapter cable is suspect, have a new one coming tomorrow to test.
Was planning to remove the ECU tomorrow and make sure I didn't damage a pin when I plugged it in. Will test with a Standard USB while I have it out. Thanks for your input.
Just heard from Shannon. Apparently they had a batch of bad adaptors and thought they had isolated them. Unfortunately mine got by them. He has one left to send. The problem he says is that the connection in the 2.5mm audio jack is wired wrong. Just wondering if it would be possible to fix the issue by re-pinning the connector at the ECU end.
Yeah, I was thinking the same thing it’s just receive, transmit and sensor ground. Rx or Tx is likely on ground?
Ah yeah, “tip and 2nd ring are reversed internally” from Shannon.
Getting the pins out of that expansion connector is the second most frustrating electrical depin I've ever attempted. It's ridiculous.
I'm guessing it's the USB adapter rather than the serial pigtail. I bought one through them and it didn't work. My serial to USB that I've used for years works fine. I bought a different adapter through Amazon, but haven't tested it yet.
The one in my white truck works just fine.
My tuning laptop needs a charge, and then I'll test the one I got through Amazon.
I'm guessing it's the USB adapter rather than the serial pigtail. I bought one through them and it didn't work. My serial to USB that I've used for years works fine. I bought a different adapter through Amazon, but haven't tested it yet.
The one in my white truck works just fine.
My tuning laptop needs a charge, and then I'll test the one I got through Amazon.
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Megasquirt (really Windows) can be finicky about USB to serial devices I've always used this and not had any issues. If you do not want to spend the money and want to go to Amazon find something with the FTDI chipset.
www.diyautotune.com
USB to Serial Adapter - Trouble Free!!
This USB to Serial Adapter has been tested and works properly with all versions of TunerStudio on multiple brands of laptops and browsers!
www.diyautotune.com
I vote for expansion port pigtail that doesn’t use 2.5mm mic. RJ45 or RJ11 would be cool. I hated the “APC” mic style when I was working in datacenters. I can deal with finding legit FTDI stuff but there’s too many different 2.5mm combos. The APC one probably won’t work - if I remember it had unique rx,tx and tip.Megasquirt (really Windows) can be finicky about USB to serial devices I've always used this and not had any issues. If you do not want to spend the money and want to go to Amazon find something with the FTDI chipset.
USB to Serial Adapter - Trouble Free!!
This USB to Serial Adapter has been tested and works properly with all versions of TunerStudio on multiple brands of laptops and browsers!
I switched the leads and it communicates. Now I am tracing down two dead holes. Trying to figure out how to test fore the injectors.
Test Mode in Tuner Studio! It's under the menu item at the far right called CAN-bus/testmodes. Disconnect your fuel pump relay or fuel pump. Make sure the lines are empty and you can pulse each injector individually. I used a "noid" light when I first wired mine, but if you have help you can simply put your finger on the injector and have someone pulse it.
The one I bought off Amazon didn't work either. But the serial to USB adapter works fine.
You can also use test mode and shut the injectors off one by one and watch for an rpm change.
You can also use test mode and shut the injectors off one by one and watch for an rpm change.
Yeah what Raymond said.
How To Do Injector Output Test:
Go to CANbus/testmodes > Output Test Modes > INJ/SPK
Click "Enable Test Mode" at the top, and click "Disable fuel pump." If the fuel pump is wired so that the ECU does not control it, be sure the fuel pump is not running.
Under "Injector testing" select output interval of 50ms, set "injector testing mode" to one, select injector "A" from the dropdown menu, set a pulsewidth of 10ms, and set total number of injections to a big # like 1000, then click "start".
You will see a countdown on the screen telling you how many injections remain before it stops. Go under the hood, and verify one and only one injector is making noise (for batch fire applications one "batch" of injectors will fire at a time). Now repeat this process selecting channels B-H. Each time, one and only one injector should make noise, and it should follow the firing order (injector B will not be cylinder 2, it will be cylinder #3).
When finished, click "disable test mode" and turn the key off.
Use PiMPx/PiMPxs FAQ (Frequently Asked Questions) | Stinger Performance Engineering (proboards.com)
and try "find" - helped me.