Author Topic: Vems connection problems  (Read 6111 times)

Offline Mohamed...e30

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Vems connection problems
« on: December 29, 2015, 03:42:12 am »
I am new to vems forums. I usually search and figure out my problem but I can't find any information on a similar problem like this. Thank you all for the help.

To start the engine is an m30 b35 with a custom wiring harness I built, turbo, meth, and vems v3.6. The car was running before I tore it apart to rebuild the motor, new turbo, bov, intercooler and exhaust. The engine hasent run more than a minute because it needs to be broken in properly and tuned.


Today after I finished wiring in the boost controler, meth controler, and the vems round gauge I plugged in the gauge to start getting it all set up
And everything worked fine. I then realized I forgot the ground for the meth controler so I removed the ground for the serial cable and added the ground for meth.

 After that I keyed the car in and the fuel pump ran constantly. I had it set to prime for 3 seconds. I tried starting the car and it wouldn't fire. After I crank the car and let off the key to injectors sometimes keep firing until I turn the key all the way off and then back on. I connected vems to my lap top and it would go to connect and then disconnect and say firmware upgrade might be needed. The problem is I cant get connected to vems to update the software.

I have tried everything from unhooking the battery, to updating the driver for the serial port to usb connector, and checking all power and grounds.

I am completely lost. I've always had problems with vems not connecting but usually works after a couple tries. I have also had a problem where at WOT the serial port will loose connection and then reconnect.

I have also pulled the board out of the car to see if anything has been burnt but I can't see anything noticeable.

I was hoping to get the car broken in and tuned next week because I am finally done and now this happens.

Offline gunni

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Re: Vems connection problems
« Reply #1 on: January 01, 2016, 11:58:37 am »
Where does the ground for your serial go to?

You should try and avoid running analogs with power grounds, do you have a schematic of your wiring or any information?

I also suggest buying a FTDI serial adapter, its far less likely to loose connection on cranking and when there is noise.

Offline Mohamed...e30

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Re: Vems connection problems
« Reply #2 on: January 01, 2016, 10:45:04 pm »
I had ran the ground for the seriel port with the ground for the vems round, ecu ground and meth ground just a temporary to see if the gauge and meth was working. It worked for a few minutes then stopped. I am now getting a message that is saying stuck in boot loader mode. I will try and ground the serial port SEPERATE and try jumping the 2 pins for the serial port. Anything else I could try?
Thanks for the help!!

Offline Mohamed...e30

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Re: Vems connection problems
« Reply #3 on: January 04, 2016, 03:54:34 am »
I separated the ground and jumped pin 2 and 3 for the serial port. Was able to get it into boot loader mode and upload a new firmware. Thanks for the help!