c4 driveability

[Carl B.]

In Oct,2015,I purchased an 87 coupe,with 6,883 miles.Beautiful car,unmolested original.The only problem? It would barely run.Rich exhaust,black soot,check engine light etc.Careful diagnosis by a local,respected tech revealed no outstanding issues.While perusing the ZIP products catalog ,I came upon this."The 27C256 Chip or EPROM in your memcal does not have an indefinite life The data or calibration will begin to deteriorate after 15-20 years." They can be reprogrammed,or replaced.I chose a Hypertech street chip.It arrived 2 days after ordering,30 minute install and voila ,ran perfectly,still does,24,000 miles later.

[Thomas S.]

Re: c4 driveability

In Oct,2015,I purchased an 87 coupe,with 6,883 miles.Beautiful car,unmolested original.The only problem? It would barely run.Rich exhaust,black soot,check engine light etc.Careful diagnosis by a local,respected tech revealed no outstanding issues.While perusing the ZIP products catalog ,I came upon this."The 27C256 Chip or EPROM in your memcal does not have an indefinite life The data or calibration will begin to deteriorate after 15-20 years." They can be reprogrammed,or replaced.I chose a Hypertech street chip.It arrived 2 days after ordering,30 minute install and voila ,ran perfectly,still does,24,000 miles later.

[Patrick H.]

Re: c4 driveability

There are also services to have your original chip rebuilt or replaced, if you wished to keep it original.

[Keith M.]

Re: c4 driveability

"The data or calibration will begin to deteriorate after 15-20 years."

Can anyone explain this? I am not expert on these..but pretty much know everything there is to know about computing. How do binary 0s and 1s "deteriorate"?

[Jim L.]

Re: c4 driveability

"The data or calibration will begin to deteriorate after 15-20 years."

Can anyone explain this? I am not expert on these..but pretty much know everything there is to know about computing. How do binary 0s and 1s "deteriorate"?

The 0s don't deteriorate however the 1s start to become lazy and lay down, resembling 0s.

All seriousness aside, I included words to that effect in a technical paper I wrote years ago just to see if anyone even read the darned thing. I never heard a peep from anyone.

[Keith M.]

Re: c4 driveability

The 0s don't deteriorate however the 1s start to become lazy and lay down, resembling 0s.

All seriousness aside, I included words to that effect in a technical paper I wrote years ago just to see if anyone even read the darned thing. I never heard a peep from anyone.

That's one good way to differentiate those who have valuable "signal" vs producing just "noise".