WTB: 7747 ECM that accepts the 27SF512 Chip

[Mitch R]

So I did Dave W's conversion with the ZIF chip on my '87 R10. Burned a new stock chip as well as a new tuned chip. And it ran great...for about 10 minutes. Then the SES light started flickering and I could only keep it running by giving it throttle at all times. I was trying to back the camper between my garage and the neighbors fence. Super fun! So obviously I screwed something up and while I could see about getting another ECM and trying again, I figured I'd see if anyone had one that they no longer needed. Thanks!

[stew86MCSS396]

Normally I'll key on engine off and observe for a rock steady SES light on. If it's flashing rapidly as you say, this indicates no communication with the PROM. I'd double check your solder connections. You make no mention of which 5 pins you added the jumper to. There's no mention of how you burned the bin onto the PROM. One can only assume you stacked the bin or used offsets. Are you able to remove the stock PROM from the carrier and drop it onto your zif with the same results?
http://www.gmtuners.com/eprom/epromcarrier.jpg

[dave w]

So I did Dave W's conversion with the ZIF chip on my '87 R10. Burned a new stock chip as well as a new tuned chip. And it ran great...for about 10 minutes. Then the SES light started flickering and I could only keep it running by giving it throttle at all times. I was trying to back the camper between my garage and the neighbors fence. Super fun! So obviously I screwed something up and while I could see about getting another ECM and trying again, I figured I'd see if anyone had one that they no longer needed. Thanks!

I have a known good and tested ZIF Modified 1227747 available.

If your interested, please send me a private message (PM) for details.

Chip offset information attached.

dave w

19035

[Mitch R]

Hi Dave, I'll send you a message shortly.

I'm going to confirm continuity in the appropriate places tonight after work, but the ZIF installation didn't exactly go smoothly. I have some soldering and circuit board experience, but hardly an expert. One of the circuit board traces came partially off with the original socket so I had to repair it by running a little wire to the appropriate ribbon cable pin at the end of the daughter board. I triple checked continuity everywhere and ensured every place had continuity where it should and none where it shouldn't but still something must've gone wrong. In hindsight, I shoud've just stuck the modified ZIF into the original socket, but I liked the cleanliness of Dave's design with the ZIF being attached directly to the board. I used a Burn 2 & TurnerPro and believe that I set the offsets correctly. It ran correctly at first, no SES light. I have tuned OBD II stuff before, but this is my first with OBD I.