openinverter forum

Last July I finally managed to get an MOT on my conversion (BMW Z4). Happy days you would think. On the journey home the car started to jerk badly and lose drive on and off. This was due, I thought, to a low 12volt battery. It was enough to make me give up my project until recently and yes the car is listed in the classifieds for sale.

Whilst waiting, hopefully, for some interest in the car I started to look at the car to move things along if no one is interested in a purchase. Now the reason for the post.

I have fitted a new zombiverter and used the 2.0a firmware, this was the latest version before the MOT. I also replaced a blown pre-charge resistor. I assume that the pre-charge stays energised even when the VCU is in the run mode and for some reason it was trying to drive the car.

Unfortunately I only have a small amount of jerky movement forward with something like 30% throttle applied. Reverse gear gives no movement but a bit of a high pitched but not too noisy whine/whistle even at full throttle. I have increased the oil pump from 30% to 50% duty cycle in case the oil pressure in the gearbox was a bit low.

Checking the spot values there are no faults showing and all indications are that the inverter is talking to the the VCU. I have removed and stripped out the inverter as far as possible to see, or smell, if anything is blown but there is nothing obvious.

Any suggestions on how to proceed would be gratefully received.

Further to my post, I have reassembled the inverter, jacked up the car and in forward the wheels start to rotate and as I accelerate there is a vibration through the transmission and then a cutting in or out of drive. In reverse there is no drive but a whirring noise. I have drained the gearbox oil and removed the sump, there are no large or small lumps of metal visible.

Is there anyone near the Andover area who has a test setup that I could visit with my gearbox to test it. At this point I am just guessing what the problem is and I don't want to buy the wrong parts to fix it.

Thanks

Regarding the listed problem I have now replaced the gearbox and inverter and the problem still exists. I am worried that the firmware on the VCU is corrupted. There used to be a blank firmware.bin file that Damien uploaded to clear the memory of the VCU and start again. Having searched the forum I found the post where the file used to be but the link to the file does not work anymore.

Does anyone have a copy of the bin file? Or does anyone know another way to clear the memory of the vcu?
Thanks for looking.

The file here works, viewtopic.php?p=33492#p33492
It unzips to a 43.4kB bin file.

Thanks royhen99. I will give this a try on Monday and see where I am.

So, it wasn't corrupted firmware but I have sorted it out. Once again, thanks royhen99

What was the issue?

I think it was a wrong parameter. Set the throtramp to 1 or higher to get drive back. It seems that setting it at the minimum value of 0.09 stops getting drive. I believe that the default parameters for throtramp are being changed.