computer / chip /reprogram???????

[LOUVETTE]

can someone explain the chip computer setup to me.....i have no idea.....ive always had older cars 60 and 70's. my 89 l98 is my first......i dont understand how the computer and chip work ....are they the same thing and what about those computer devices that u plug in to change the settings like fan on ect.......cant u just reprogram the stock chip to do these things with one of these computer setups..........instead of replacing the chip or computer??????any help understanding is apreciated..........thanks....lou

 

[-=Jeff=-]

Okay to start with.. those computer devices you mention that plug in and change settings are only ggod on cars that use a PCM instead of the ECM (PCMs came out in 1994 in vettes) so that device (like the Hypertech Programmer) will not work for you.

Your 89 Corvette has a MEMCAL inserted in the Computer (ECM). Since the ECM used in your corvette is also found in several other GM cars the MEMCAL has the Program SPecific for that body style.

On the MEMCAL for the 89 there wis 3 Integrated Circuits (ICs) 2 are used when the car goes into Limp Home Mode. the 3rd is a EPROM (Erasible/Programable Read Only Memory). so basically to change the program you would need to use UV light and re-program the code into the EPROM, of Course first you would read the information out the the EPROM before erasing it.

The Main reason Many Guys will buy an Aftermarket PROM is to retain the Stock as a back-up or when they sell the car. Since it is fairly easy to replace the MEMCAL this is why most companies offer that. So yes you can Re-program the Stock CHIP.. but it is always good to have that stock one left untouched just in case.

Hope this helps.

 

[ddmau]

So Jeff, the near $ 200. I spent on a Jet Performance chip for the '85 was basically a waste because the car has an ECM? I understood an increase in horsepower would result just by plug N' play. Is this a buyer beware deal?

 

[-=Jeff=-]

So Jeff, the near $ 200. I spent on a Jet Performance chip for the '85 was basically a waste because the car has an ECM? I understood an increase in horsepower would result just by plug N' play. Is this a buyer beware deal?

No absolutely not!! I just re-read my post and it is some what confusing.. all I was saying about the Aftermarket PROM is that it is the better solution then reprogramming the Stock PROM so when/ if you would sell the car you would have the Stock PROM to replace in the car and then sell the Aftermarket one separately.

The Aftermarket PROM is the way to go in the MEMCAL type cars..
Infact that is how I sell my PROM. it is a replacement to the stock one

Hopefully this clear things up more.. if not please ask more questions

 

[ddmau]

Yes, thank you...very clear now. Still, one day I'll be contacting you for a custom chip...just don't have the mods now.

 

[WhalePirot]

See This!

I highly recommend this book, written by a once dealer mechanic; now PhD, having taught at GM Institute.

I have the soft cover book, which is packed with information on how ignition systems work, from points to ECMs. It took all the mystery out of my computerized engine.

One source:

http://www.addall.com/Browse/Detail/0929603370.html

Get it somewhere, all you enthusiasts! BUT, good luck finding it.



Did I mention that I highly recommend it?

 

[Ken]

Mike, what is the deal with that site? I tried to find the charges and was going to buy it. I searched for the title to see the comparison pricing I got three returns, all Amazon (yet three different prices), and they all stated:

THIS TITLE IS CURRENTLY NOT AVAILABLE. If you would like to purchase this title, we recommend that y...

It ends there.

_ken :confused

 

[WhalePirot]

what is the deal with that site?

Not sure what that means, unless it's not available, period.

U wanna borrow mine? I want it back, and will hunt down anyone who won't like a mongrel dog. LOL

It has been to Ventura already.

Maybe I need to check with the publisher to see about a reprint.

How many guys are interested?

 

[Ken]

Thanks anyway Mike, but if it's as good as you describe I'd want it for my library.

_ken