I have been having trouble reprogramming my stock chips for my 1988 Firebird and I was wondering if they wear out or take a memory? The first few times I erased them and reprogrammed them everything seemed fine but the more I erase them and reprogram them the harder it is to get them to program. It some times takes me 10 tries to get the chip to program after it is erased. The pocket programmer II that I use says the chips are erased but they will either not program or not verify to the buffer. I then have to erase the chip again and start over, sometimes this process will be repeated 10 times before I get the chip to program. Is there something I am doing wrong or are the chips taking a memory that is hard to erase? The chips I am using are the 27C128 style which are UV erasable.

Related to that subject are there any chips that I can substitute for the 27C128 chip that are electrically erasable and programable from my pocket programmer II, I would think an electrically erasable chip would be faster to reprogram.

Thanks for any help.

 

Well, I dont think so, but I guess they could go bad being subjected to a static change. This might happen to one Eprom but not all of them. maybe you are doing something wrong, I would not know what.

I started with 4 Eproms and perhaps programmed 120 times with my Pocket Programming. I never set my Eproms down on a metalic surface and I am not insulated from the carpet. My Eproms will erase in about 10 minutes and I can program them right away.

Sorry I'm not being much help here.

 

I think wiht some small changes or maybe with no changes at all something like a 28C256 EEPROM could be used. Dont quote me on that. Check the pinouts. Grounding one pin should allow you to use the chip in its place.

 

You can use AT29c256's, just double stack the bin.
Much easier than erasing eproms!

 

In some obscure web site they mentioned the last 27128 type eprom chip was manufactured in like 1985.

Might just forget the *E* stuff all together and get some of the EEPROM 256s.

 

Thanks for the help

 

There was a post a while back from Grumpy that said you should wait a little after the key is turned off before removing the chip.
I'm not sure exactly what the technical end of it was about, but the chips would go bad after doing it more than a few times.
I tried to search on it but could find the post. Maybe someone will chime in.
Not sure if it applies to UV types but IIRC, it wasn't good to do and made the chip fail later than sooner so it would be hard to find what happened.

 

The reason is that the ECM stays powered for a few (my 1227165 is about 12) seconds after the key is turned off. This allows things such as MAF burnoff, IAC reset, etc.