DIY PROMDo It Yourself PROM chip burning help. No PROM begging. No PROMs for sale. No commercial exchange. Not a referral service.
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I need to read/burn 1983 LG4 timing curve. Can it be done?
Hi guys, I have a 1983 LG4 CCC Qjet setup on top of a 1987 TPI long block. I already burn my own proms for 6E MAF TPI stuff. Can I read the 1983 LG4 chip with my Moates Burn1? What type of chip do I read it as? Once I have read it, can anyone decipher the timing table? I would like to modify just the timing, I really don't care about anything else. I am retaining all emissions equipment so leaving it functional is good.
__________________ 1989 Trans Am, 1979 Z28 w/ Holley Stealth ram and MAF '165 ECM, 1988 Chevy K1500 w/ L98 and TPI swap, 2003 Mercury Marauder, 2004 Taurus SEL
The existing chip is a N82S181. 2532 is a drop in replacement for the ECM. To read the original I created a jumper between VCC and pin 18 and clipped pin 18 so that it didn't touch the zif socket. It reads as 2732.
Once you read the chip look for 00 10 00 0C at 030 ish. This will be the main spark table. reference the 87 hack for the size and scale of the table. The hack is under $40 at moates fileman.
Thanks! The only experience I have with proms is using Tunerpro, which shields me from actually having to know how to manipulate the hex. What is "VCC" that you reference? When you say you clipped pin 18 you mean it is attached to VCC, whatever that is, but pin 18 does not make contact with pin 18 of my reader?
Once I have manipulated the timing table do I have to change the checksum? If so how do I calculate that and where is it located? Is there a flash burnable chip I can write with my Moates Burn1 that will drop into my ECM? Will I have to add any jumpers or manipulate the pins on this replacement prom?
I will be SOOO THRILLED if I can write my own timing table for this piece of crap CCC setup.
Here's a link I found for the pinout of that chip. N82S181.pdf - 8K-Bit TTL Bipolar PROM
VCC is the power at pin 24 if its the "N" style BTW.
Curious to delve into my LG-4 too. (got too many projects right now though)
I do have an ADS for my 85' that I made but never got working due to the command codes. I've got something simply stupid wrong in there like the payload offset or something, just never had time to figure it out yet. I'll shoot it over to you if you could try it out and give me some feedback if you get it to work.
John
What I did was remove the Eprom socket from the ECM I was destroying and soldered a wire between pin 24 and pin 18 right up near the plastic part. Then I cut off pin 18 on the socket so that the pin would not be affected by the reader.
These computers have no checksum. They originally come with BPROMs that cant change.
I also use tunerpro. Set the checksum loaction to 3FE. Sum is not important but some versions on tunerpro want to be able to calculate it.
Use 2532 chips.
Consider getting a 1228079 ECM. The hack for this one is available and the code is more sophisticated with respect to timing.
