First off - I am VERY new to the PROM tuning world. I just got my Pocket programmer a few days ago and have yet to purchase TunerCat so be gentle.

This is about the chip in my Dad's 86 LPE 383 Vette with a 165 ECM. This started because I wanted to find out what TDF I was going to need because this car was modded by LPE to remove the Cold Start Injector so I did not know if it was going to be 32,32b or 6e or whatever. I was also curious to see what LPE had thrown in there for values.

I looked at TunerCat's website and found their neat little checksum utility that tells the ProgramID byte.

The problem is that after I read the data from the chip with the PP2 software and opened it with Checksum it said the ID was AAh and that the checksum was invalid. What is AAh - not one of Tuner's supported IDs.

To make sure I was doing things right I did the same thing with a junkyard 7730 chip (spare for a different car) and it showed up with A1h (Buick/Pontiac 3.1 V6 - I got it from a V6 Cavalier so this sounds OK) and the checksum is fine.

What is happening here? Is there something funky with the LPE chip?

Thanks for the help!

Dale

 

The checksum will change every time a value is changed in the chip. This is the ECM's "sanity check" to make sure the chip isn't corrupt. My guess is that it's fine.

Would you be able to email me the .BIN file if it's not to much trouble? I'm always curious what kind of changes all those bigger places make. Email is quiktrp@netzero.net.

Thanks, and good luck with your burning

 

$AA is what can be used to "disable" the checksum.

The program is likely $32 or 32b and what you want to change it to is $6E.

HTH

:edit
Had the Mask ID's switched!!!

 

AA essentially means "no checksum." You'll see that occasionally with modified bins, especially the older stuff. Nowadays, we have all these cool editing programs that automatically compute the correct checksum for you, so that practice has become pretty much obsolete.

If the cold start injector was removed, there's a pretty good chance it's a 6E.

 

What Dave said. And to be clear, without the CS injector, even if it isn't $6E, you should have no trouble using a $6E bin. Its highly recommended. The only thing you *may* need to do to go with $6E (if it hasn't been done) is disable VATS. Its on bit to flip.

If you like, send me the original bin and I'll tell you whether its $6E or $32 (or $32A).

M

 

Lingenfelter was privy to inside stuff from GM, so don't be surprised if you can't read it, or if some of it just doesn't make any sense. It might be normal, just no guarantee.

 

Thanks for all the help!

Question 1: If I go with the 6E (sounds like the most advanced) why would I have to disable VATS? The 86 has VATS - or did they change the way it works by 89?

Question 2: Can I still (easily) get the tune off the chip to use elsewhere if it is not 6E? I would hate to start over - I don't think I have the brains for that at this point.

I'm in over my head and haven't even started yet


You guys are great!

 

I am going to go out on a limb and say it is probably not 6E.

I downloaded a copy of TunerPro with the 6E and many of the numbers don't make sense. There are 0.00s in the middle of the MAF tables, the fuel cut-off RPM is 47 RPM, etc.

How could I check to see wha it really is - assuming it is not set up like Grumpy said it might.

Thanks

 

Check it against a plain $32 ECU and a $32B ECU as well and see if the numbers begin to make sense. If not, you're probably out of luck in terms of editing that particular bin.

Regarding the VATS issue, I didn't realize '86 had VATS, but if it does you certainly will not need to disable it in the $6E bin. Bonus!

 

I just took a look at the bin. Its $32. I emailed 86Chicken the appropriate ECU to edit this bin.

 

I got the 32.ecu file and the data appears to make sense to me.

Thanks for the help! I really appreciate it!

BTW: I downloaded a copy of TunerPro and it seems like it will work great for everything I need it to do - a really nice program.

Now I just need to search and learn how all this stuff works.

Thanks again!