Fuel Pressure Goes To Zero When Car Starts

[2JZNA-T]

But those are just grounds. All the grounds have continuity between one another.

But if the 12v supply line doesn't have continuity between it and the ground. in my opinion that means there is no connection between those two in the circuit.

Meaning even if 12 volts is supplied its not going into the circuit.

But the grounds them selves do have continuity.

I did check the usb and its fine.

[Angelo S38]

Nope ECU ground, Sensor Ground and USB are seperate from the power grounds. So with the device disconnected there is no continuity between the power grounds and the others.

[2JZNA-T]

I was talking about the pins on the ECU between B17 and G18 not the contacts on the USB.

I was talking about the continuity on the pins where the ECU connects to the harness. There is no continuity between the 12v on g18 and b17 (ecu ground )

I even tried to test the resistance between those pins and there is no reading.

The reason i've been focusing on those pins is because those two pins are the ones that supply the main voltage to the EMU. If there is some sort of issue in the circuit with those pins the emu will not get any power.

[Angelo S38]

I'm talking about the same thing, I've measured on mine.
There is continuity between B18, B17 and the outside metal of the USB plug. But not between the pins I just mentioned and the other power grounds.
Between the powergrounds themselves there is continuity.

[2JZNA-T]

Then i have no clue what is wrong, i've already tried buying a new USB cable. Still the same " disconnected "

Made sure the harness has the supplied 12v going through to the emu. I also tried the test where you take some of the extra wires and connect the emu directly to the battery and it still doesn't connect.

I also have tried the program on a total of 3 laptops. So i doubt all three laptops would be damaged or not working. And considering i bought another usb cable i don't see how i could have somehow bought another bad usb cable.

Which leads me to believe its something with the emu itself.

I sent it back to have it tested. If it comes out fine. Then i have alot of frustration ahead.

[Angelo S38]

That's the best step I think, hope you get it sorted soon. Best of luck.

[2JZNA-T]

Yeah they have really helped me with my questions. I just hope there is something that can be sorted out. I can maybe buy a third USB but i find it hard to believe that it would fail. Even the computer shop that i was talking to was saying its very rare for USB's to fail if they are not damaged from cutting or a rip. They were telling me that its unlikely but i can maybe order one more.

[Kisielisodd]

Troubles that bothers you is very strange. Usually no one complains to USB communication.
I was asking about continuity between USB metal housing and sensor ground (B18). There is protection against short circuit and huge potential difference that can happen when laptop is supply from cigaret lighter. We have one ore two cases when protection saved whole ECU.
From discussion, finally, i didn't find out if there is continuous between USB and sensor ground (measured without connected EMU to wiring) .

[2JZNA-T]

I have no clue what it could be.

The emu was getting 12v to its power supply pins, i had went through a different usb cable in an attempt to see if the usb cable with the emu was bad.

I also tried 3 laptops with the program and i doubt all three latops would be faulty or working incorrectly.

[Jadzwin]

The EMU should be checked. Maybe the USB connector is broken.

[2JZNA-T]

Yeah i mailed it back to them last week. Should be there today.

I told them every thing i've tested and exactly what i've been experiencing.

One thing that jumps out at me in the situation is the fact that it suddenly experienced this problem shortly after adjusting the fuel pump to invert the signal.

Which is why i assumed initially that it was a problem with the EMU, because i didn't even have time to press F2 in order to have that written into the data flash memory. I inverted the signal it was working and soon as i was about to click " make permanent " the car shut off and it read disconnected.

Im wondering if there is a issue where the emu was damaged when the car stalled right after i adjusted something and didn't have time to make permanent ?

Another thing is when the emu was hooked up AFTER this all happened i can tell its still operating certain things like the fuel pump and spark. because if i crank it over the car it start for just over 2 seconds then die.

[2JZNA-T]

Update

So ecu masters has confirmed that my emu standalone is in perfectly good working order.

Its bitter sweet news because im happy that its fine. But i know now that im going to have to spend awhile to get my laptop to somehow work.

I've looked on some of the drivers some of you have recommended and downloaded them and still have the same result.

Hopefully i'll get it sorted out soon. I feel like its gotta be the cable that i bought. Maybe it was a faulty one.

I just don't see how three laptops could fail and have the same result.

So im narrowing it down to the cable it self.

Hopefully thats all it is.

[Angelo S38]

Maybe they can send a cable (which has ben verified to work) back to you along with the device so you're sure it isn't the cable?

[2JZNA-T]

They said they were gonna do that. Said everything tested out and is including a cable in the box that is known to work properly.

[2JZNA-T]

Luckly the usb cable they supplied works !! I was able to get the car running. But can't get it to idle on its own.

It needs my foot on the gas in order to maintain a 1000 rpm idle.

If it does idle, it idles extremely rich ( in the 9's ) and barely is capable.

So i figured id try to lower the injector trim down. Starting from a 100% and the lowest i could get it was about 80%. Any lower than that it just wont idle at all.

Any tips on how to make the car idle ?

Thanks

[Wuniek]

Any tips on how to make the car idle ?

you can try correct it by idle ref table and correct frequency of stepper motor ( assuming you already know correct step number )

[2JZNA-T]

Honestly have no clue, as far as i know this is the first plug n play for the 2jzge.

I had to have them re pin certain things on the harness in order for it to work.

And they uploaded a base map but i have had to adjust abit in order to get it all atleast running to the point where it can go through the rpms with out any hesitation or issues.

Im new to tuning but my main goal was to get the car to atleast run to make it driveable to drive it to a tune shop. Considering tune shops are not local or near by, towing it would be extremely costly and i simply cannot afford it. So im trying to just get it running so i can come to a stop without any stalling.

[Jadzwin]

Please contact us on monday at tech(@)ecumaster.com. One of our engineer will connect to your computer and check your settings.

[2JZNA-T]

got the car to idle now, the idle rpm ref was at a 100% i've been slowly stepping it down. And got it to go from barley idling at 9.40 to now about 10.30 afr.it idles alittle more reliably and much more smooth. But i can tell i need to mess with more.

[Jadzwin]

Modify your VE table in the idle area