LCD refresh request for 1.1.x firmware

[BenFenner]

dnb told me to shield my LCD wire, and put a ring magnet around it to help with the LCD character dumping. I've done both, and neither helps any. It may be my grounds, and some day next century I'll get to that, but I'd like to put in a request for the same LCD updating done in the 1.0.x firmware to be put in the 1.1.x firmware. From what I understand of what dnb has told me, the LCD character dump problem is entirely fixed in the 1.0.x releases, but it seems that fix didn't make it to the 1.1.x firmware.

[dnb]

I'm surprised the fix isn't in the 1.1.x because I asked for the fix way back in the days of 1.0.23!

Is it that the display turns to trash or does the ECU go into map edit mode?  I have the latter problem and think it's noise getting in to the PS2 keyboard interface.

[BenFenner]

The LCD gets random characters dumped to it in mostly random places (some places are more common than others).
It seems to be rpm dependent. I can drive for ever on the highway without it messing up, but once idle goes below 1200 or so rpm, it starts messing up. The lower the rpm the worse it gets. And a throttle tip in it can happen more often.

With MegaTune hooked up, it seems to coincide with the ???Missfire??? blinking red warning. I get quite a bit at lower rpms, and it seems to have something to do with the timing of when the LCD messes up.

[dnb]

I really suspect a grounding issue somewhere.  I don't suppose your car will run on the 1.0.73 firmware (the same as mine) to emiminate either the firmware or the car from our enquiries?

The ???Missfire??? indicator is a strange one.  In MT I believe it is caused by sudden changes in RPM,so this could be real (in which case there is a misfire) or it could be a trigger error causing an apparent change in RPM.

[BenFenner]

No, from what I know, I can't run anything but the 1.1.x firmwares on my crazy Nissan.

So the misfire comes from sudden change in rpm aye? I'm not sure if it's trigger errors or real misfires. I thought it might be lean misfiring for a bit so I enriched my idle a little to ~1.00 but haven't seen any change. I think sometimes there is true misfire, and the idle bogs (this is very rare) and the LCD certainly goes mental when that happens.

As a side-note. DanMartin's BMW gets the LCD character dump now (never did before) after installing his new 670 cc injectors. He has terrific grounds and wiring, and runs 1.0.73 firmware. He has a shielded signal to the LCD, but no ring magnet.

[BenFenner]

Could post number 12 in this thread explain my frequent missfires?

http://www.e30tech.com/forum/showthread.php?t=53517

My P.259 channels are toast as well.

The cause of the trigger signal loss was due to the dead "P259" circuit which I simply removed. When it has died it pulls down the +5V to the point where the ADC signal conditioning chip that is fed the trigger signal can't do it's job - never mind the main CPU. The chip has 8 low power outputs (<500 mA) which are suited for grounding relays, but it has been found to have too poor voltage flyback protection on its outputs, that causes it to short-circuit the outputs when driving heavy relays (strong coils) so one must use extra protection diodes to work with them. It could have died because of that, or from poor grounding.

[rob@vems.co.uk]

No, if the p259 is dead then you get no VR, the chip pulls the power to the VR sensor chip and thats your lot.
And you are using Hall so thats nto going to be effected.  I'd sort the dead p259 chip though

Log those misfires and we'll track them down.

Rob

[GintsK]

I have success with hopeless garbage on LCD, when injector PWM is used:

I do 3 things:
1) Put cap parallel to flyback voltage limiter - normaly TVS diode.
2) Make LCD and keyboard wires inside ECU short as possible and route it farther from power transistors.
3) Install 0.1uF cap between supply on LCD PCB

What of those solve problem - don't knew. I perform all things at once. If someone have patience do it in sequence, please keep us posted.

I see additional measure regarding ignition: put cap between ground and coils supply near at coils.
Some manufacturers do so.

Gints.

[BenFenner]

Log those misfires and we'll track them down.

I have to happen to have the laptop in the car, and it has to misbehave, so I'm a bit slow in getting those logs. They are in the making though.