1228746 ecm w/vats

[jknightandkarr]

Question on the 1228746 ecm. I have an 89 trans-am with the vats 5.0 tbi and wondered if 1)anyone had disassembed that ecm before and 2)If anyone could help me id the components on the ecm circuit board? I know where the 68hc11 chip(s) are but theres a total of 3 chips all same pin count but not really know what the rest of the componentsare other then capacitors, resistors, diodesthat sorta stuff. Thanks

Joe

[sturgillbd]

See here http://www.exatorq.com/ludis_obd1/schematics.html
and here http://www.exatorq.com/ludis_obd1/c3pinouts.html

[jknightandkarr]

Cool. Thank you very much! Now just need the computer's ecm program. I have the one listed on this site, hoped that someone might know a source for the vats version.

Joe

[sturgillbd]

VATS was enabled on the F bodies like Camaro and Firebird. It wasn't enabled on caprices. If you have a chip programmer, you can pull your chip and read it. You just have to be careful in removing the EPROM from the plastic carrier. I have one for a 1991 Camaro with 305 and 5 speed manual. It was a Hypertech chip. Both 8746 ecm's I own have Hypertec chips. I don't have any original bins.

[jknightandkarr]

That i dont have. Where can i get one at?

Joe

[sturgillbd]

Ebay, http://www.ebay.com/itm/SIVAVA-Wille...-/251934829226 You must have a parallel port on your PC to use this one. I use this to program and erase winbond EEPROMs that you find on ebay and other places

Moates.net https://www.moates.net/burn2-chip-programmer-p-197.html Works great for flashing and erasing genuine SST27SF512 chips. Will program but not erase the winbond "fakes" that are on E-bay. Get your chips from Moates, MCUmall or Xenocron.

These are the two I own. There are plenty of other programmer/readers out there. The BURN2 is the easiest to use with TunerPro. TunerPro has built in support for Moates hardware. If you plan on tuning this vehicle, you may want to read http://www.gearhead-efi.com/Fuel-Inj...ght=7747+flash This thread is about modifying a 7747 but the 8746 is the same as far as the socket install. You have to be extremely careful when you remove the old socket. If you damage any of the traces in removing the original socket, it can be a pain to repair. Read the above thread thread carefully. It will save you some grief. There are several tuning threads on this site. I advise you to read and try to understand the process before you even attempt tuning. There is a wealth of information on thirdgen.org in DIY Prom http://www.thirdgen.org/forums/diy-prom/

Hope this helps,
Brian

[jknightandkarr]

Thank you. Do you happen to know how i can pull the program itself from the ecm. I have the ecm program from an 89 Caprice but wanted the vats ecm program so i can try and plan a custom ecm project for my car.

Joe

[Six_Shooter]

sturgillbd just explained what you need to do what you're asking.

You need a programmer to read the EPROM.

The programming will be very similar between the F-body and the Caprice and all of the same abilities will be in both vehicle's programs. The VATS is a simple flag that gets enabled or disabled.

[jknightandkarr]

Ok so the programs are the same just the only diff is the vats flag n obviously the cal chip?

Joe

[sturgillbd]

Here is a non-stock 305 with TBI and 5 speed manual bin from a 1991 Camaro. Open it in TunerPro with the $61V2.XDF.

http://www.gearhead-efi.com/Fuel-Inj...101-61-1228746 See post #6 for more bin files. There is a thread dedicated to the 8746 ecm here: http://www.gearhead-efi.com/Fuel-Inj...Information-61

[jknightandkarr]

Actually i think i already have the cal chip dta for my car original set up. Thanks.

Joe