OK, here's the story...I recently swapped my L03 305 for a 350 H.O., so I pulled out my EPROM and changed my AXKW bin to an ANLU bin as an initial stab at a new program. I was sure to disconnect the battery before I touched the ECM, too. But.......now the engine won't fire and I'm getting a code 51 (ECM or PROM failure).

SO, I disconnected the battery again to clear the codes, made sure that the ECM connectors were plugged in properly, reconnected the battery and tried to fire the motor again.....nothin'. It turns over, but that's it.

I had someone watch the injectors to see if they were spraying any fuel at all as I cranked it and they weren't doing anything. Guess that explains why it won't crank...but what's up???? (yes, there is fuel in the tank by the way ). The strange thing is that the plugs now appear to be fouled and wreak of fuel...it was apparently getting fuel at some point for that to happen, so that's kindof a head-scratcher. Of course, the fouled plugs would definitely prevent the engine from firing on their own, but I know I have other problems as indicated by the code 51 trouble code. One more thing...I got a code 12 three times when I started checking my codes, which I thought indicated that the ECM was functioning properly.

Can anyone help me out here? Do I just need to burn the EPROM again, or is my ECM toast?

 

Anybody got any ideas?

 

Code 12 will always be shown before any stored trouble codes, so in essence the ECM is functioning properly.

Recheck to make sure the PROM is seated fully, and not installed backwards, I know "It's impossible to do that", apparently not, when you force it, I have read about a few people doing that.

I'm not sure on this, but maybe a PROM ECM compatibility problem?

 

Try the original chip, and see what happens. It won't run well, but it should at least run.

And if it sets a 51 then it would be likely that it's the ecm, not the chip.

 

Thanks for the replies.

I'll recheck the PROM, but I did make certain that I had the notch facing toward the inside of the ECM, which I believe is correct. As for incompatibility, I think that the ANLU bin is supposed to be compatible, but who knows...maybe the bin was corrupt or something. I downloaded it from the diy_efi ftp site...anyone got an original, unmodified ANLU bin that I could use?

As for the original chip, unfortunately, I had to erase it and burn the new bin on it because the 27C32 chips I bought from Jameco were not compatible with my EPROM burner (National brand, I think...anyone know of a company that carries a different brand?). As for the ECM, I was hoping that my code 12 indicated that the ECM was functioning properly, like Raven said. I know that anything is possible, though. I'll try pressing the chip in further, reset the codes, and see if I'm still getting a code 51. Let's hope for the best...I'm SO ready to take this thing out on the street!

 

I just want to make certain I understood you on this. I went and looked at an old memcal with the prom still soldiered in it and see that the notch faces out from the memcal. I just wanted to make sure yours is facing the same way. If not thats your problems.

 

I guess a MEMCAL ECM for a TPI car is different from a TBI ECM...check out this web site:

http://www.tbichips.com/chipinstall.htm

My chip was in exactly the same position (notch facing in) as the picture on that web site, so I'm pretty confident that it is correct...thanks for the input, though.

 

One more thing...I forgot I had a pic of the chip before I removed it. As you can see, the notch was facing toward the inside.

Man, you really had me freaked out there for a minute...

 

Sorry about that didnt realize it was different for tbi. I looked on a maf and a sd tpi memcal is why. Trying to rule out all possibilities. I soldiered a prom carrier in my memcal once and even though it looked nice and all the connections looked good they werent. It wasnt till I took a continuity tester to every pin and found out that I had bad connections did I solve my problem. I would check to see if every pin is making contact by testing as your eyes can fool you so it seems.

 

Just to completly eliminate any PROM issues...

You had to remove the chip itself from the carrier, Correct? Are you sure you placed the PROM back in teh carrier in teh right direction?

Just thinking of other possible scenarios.

 

Well, I pulled the PROM out and verified that the notches were both facing the same direction. In the process, I noticed that some of the pins didn't appear to be properly seated in the plastic holder and I just KNEW I had found my problem. I put the pins in place, relpaced the chip, reconnected the battery, fired it up......nothin'. It is still throwing a code 51 and I don't believe the injectors are spraying any fuel.

Does anyone know how I could use a voltmeter or something to verify that my ECM is OK, the EPROM is OK, and that the EPROM is getting a good connection to the ECM? Man, this is so frustrating...I've got a brand new engine/tranny combo and I can't even try it out. Thank goodness I have a spare car to drive for now!