Hey guys, I'm having massive problems with my first shot at PROM burning.

I desoldered the GM EPROM(aujp 1615)in the memcal and soldered in a ZIF. I put the AUJP chip in the ZIF and the car started and ran normally. I then took the aujp.bin and changed the VSS switch that I thought would allow the ECM to recognize the signal from the cable driven VSS on my '89 IROC. I plugged the newly burned chip into the ZIF and the idle was very funky, choppy even for the LT4 hot cam. So I plugged the AUJP chip back in and the idle remained, but after fiddling with the PROM in the ZIF the idle returned to normal. I double checked for continuity thru the ZIF to the pins and everything is cool. However now the car refuses to start, I smell the fuel but no spark, even with the GM chip. I was unable to get Diacom to link and the ECM won't flash a 12 code for me so I swapped ECMs with no change. Just a solid SES light and the fans run. Can anybody help me out here, what have I missed? The car started and idled (although poorly) with both chips now nothing. Did I zap something?

 

I know this is a lame attempt at diagnosing this but have you tried to unhook the battery for a few minutes ? Maybe you burned the ECM fuse somehow ? Look at the one on your fuseblock and also the one next to the battery... Sorry that's all I can think of. :/

 

Thanks for the tip Blade, I checked it out and everything is cool, the ECM is getting juice. I was able to get a diagnostic code 12 so the ECM is alright, apparently the prom and/or whole memcal is toast? I can't figure out why the GM chip would work fine one minute and not the next. Static discharge? Has anybody else had this much trouble burning PROMS? Isn't it at least possible for the car to run with a bad/missing EPROM, via the limp-home mode?

Also, when I burn an EPROM and then immediately d/l the .bin for viewing in TunerCat it says the .bin is not of the right type ($8D)what gives? I was trying to verify that the .bin i was burning into the PROM didn't change. What have I missed???

Thanks in advance,
Drew

 

So I plugged the AUJP chip back in and the idle remained, but after fiddling with the PROM in the ZIF the idle returned to normal.

Might want to go over all the solder joints again. I think someoneelse had trouble with soldering in a zif socket. Reheating the joints fixed the problem.

Also, when I burn an EPROM and then immediately d/l the .bin for viewing in TunerCat it says the .bin is not of the right type ($8D)what gives? I was trying to verify that the .bin i was burning into the PROM didn't change. What have I missed???

Something is corrupting the data. After you burn the eprom run a Verify device to buffer in you burner software. Sevral times. Run Checksums for device and buffer, they should match.