Bitrot

For those of you not faint of heart, who believe the Volvo 480 should have more torque and horsepower, find all you need to know in here.

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Robou
Knows an Aerodeck isn't a 480
Posts: 270
Joined: Sun Jul 08, 2007 11:34 pm

Bitrot

Post by Robou » Thu Aug 25, 2011 7:15 pm

The contents of Eproms have a limited lifespan. Most manufacturers guarantee the reliability of the programmed bits for a period of 10 years.
While programming the gate of transistors holding a 0 bit is charged and in time this charge fades away. This decay is a physical phenomenon, accelerated by high temperature and ultraviolet light, nothing can be done about it. Eproms have been replaced by Eeproms and flashmemory, being less vulnerable.
Every eprom used in the EZ210K with 2 PCB's and the LH2.2 is subject to this so called bitrot. Like a human old age brain disease it is insidious, the ECU doesn't stop working right away. Moreover, in the EZ210K only ¼ of the contents is actually used.

Before programming an eprom with the mod I compare the contents with the original binary in a weak attempt to filter out defective ones not to be used for reprogramming. I got rid of 10% already before I realized what the real culprit was. It should be mentioned I checked the complete contents, not just the used part.

When constant, subtle and incurable problems occur in the motor-management it could be advisable to use an ECU of known good quality to check if the problem is persistent. As a matter of fact any eprom, after a period of about 20 years, should be reprogrammed. This guarantees the contents for another 10 years. Name it preventive maintenance.

Reprogramming is an easy job. Beware, it should be done with the original known good binary, not with a copy from the eprom itself, as it may be partly faded. If an exchange service is called for (anybody?) I'll be happy to provide reprogrammed eproms with the original binaries for orange, purple, red and blue EZ210K's. For the LH2.2 I only have the red and green, but if there's some interest it should be possible to come by the missing ones. I have no intent to run such a service myself, just willing to provide reprogrammed eproms in bulk exchange at no costs, but for postage.
Too old to bother
480 Turbo midst '91

Djsmiler
480 Newbie
Posts: 14
Joined: Sat Dec 03, 2011 10:26 pm
Location: Warwick Warwickshire

Re: Bitrot

Post by Djsmiler » Tue Jan 31, 2012 4:40 pm

robou, could this bitrot business be responsable for an intermittent spark? i.e the car works fine for 2 mins then just dies from loss of spark? i have replaced everything else apart from complete loom and ecu's. i have a purple EZK in mine. I have a thread started about this problem now but if a few people tell me this could be the issue then i may be very interested in this service you speak of.
all the best.
Chris

Robou
Knows an Aerodeck isn't a 480
Posts: 270
Joined: Sun Jul 08, 2007 11:34 pm

Re: Bitrot

Post by Robou » Tue Jan 31, 2012 10:06 pm

Remarkable it took about 6 months for the first reaction, whereas the phenomenon is very much a real-life one as anyone familiar with electronics will know.

The answer to the question is: I don't know. As I said in my post, the only way to find out is by trying an ECU of known good quality or replacing the eprom by a known correct one. In theory it could very well be, the program being addressed to a wrong place in memory or missing an interrupt stopping the ignition, but likely...I just don't know.
The only way to rule this out is by refreshing the eprom. This having done one can start fault finding with common sense.

But seeing your posts in different threads I would say you're playing in another league. Replacing the boost pressure control valve and the recirculation valve, just that, will not bring you anything but problems and probably a blown engine. And it will most certainly not work right with the ECU's, modded or not.

I would be glad to send you a freshly burned eprom but I'm afraid it will not be of any help in your case.
Too old to bother
480 Turbo midst '91

Djsmiler
480 Newbie
Posts: 14
Joined: Sat Dec 03, 2011 10:26 pm
Location: Warwick Warwickshire

Re: Bitrot

Post by Djsmiler » Wed Feb 01, 2012 12:21 am

post removed then. wrong location for thread
Last edited by Djsmiler on Wed Feb 01, 2012 12:34 pm, edited 1 time in total.

Robou
Knows an Aerodeck isn't a 480
Posts: 270
Joined: Sun Jul 08, 2007 11:34 pm

Re: Bitrot

Post by Robou » Wed Feb 01, 2012 10:54 am

This all is not about bitrot. I advise you to make a compilation of your posts in different threads and open a new one. Glasgowjim may advise you in doing so and getting rid of your "polluting" posts and this one (mine) as well. In the meantime I'll ponder about your ignition problem.
Too old to bother
480 Turbo midst '91

Djsmiler
480 Newbie
Posts: 14
Joined: Sat Dec 03, 2011 10:26 pm
Location: Warwick Warwickshire

Re: Bitrot

Post by Djsmiler » Wed Feb 01, 2012 12:35 pm

thank you robou.

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