JTB91RS

I did some digging, but didn't notice anything on this subject (though I apologize if it has been asked before). I was wondering if all V8 memcals for a particular ECM are the same besides the BIN on the PROM.

I have a newly rebuilt LO5 350 with a 280XFI cam, flowtech shorties, and a TPI setup converted to SD that I am putting in my '91 RS, and I am looking for a MemCal that I can use. I know the V6 one that is currently in the 7730 won't work (loses ESC and Limp), but will any V8 7730 memcal from a 305 or 350 work if I adjust the bin, or should I be looking for a memcal with a particular broadcast code? Also, are there other ECMs that can interchange memcals with the 7730?

jwscab

all memcals are usually slightly different. especially with regards to:

ecm used
engine displacement
broadcast code(binary file programmed).

the memcal can contain: a prom; limp home mode resistors;knock circuitry.

if you are burning your own chip, it doesn't really matter what is contained in the prom portion of the memcal, but it is a very good idea to match the memcal with the correct ECM. less so, the engine calibration.

you should start with the latest file for the prom(latest factory tweaks) unless you are looking for a specific type of file (boost, etc).

the best bet is to use the closest engine size, ecm type, and latest broadcast code.

for your use, you should use a memcal for the 7730, which will have the knock circuitry, the prom, and limp home mode resistors. You should also use the memcal for a 350, which will match the cubes to the LMH resistors, and knock circuitry for a 4" bore.

there are alot of little details that would allow you to possibly use other memcals, but you really should start with the right thing to prevent this from being a problem as you get the engine up and running. one less problem to solve.

3.8TransAM

Use the 350 memcal.

General rule of thumb is use the closest factory applicable to your application for all the reasons stated above.

Some people have had success in retrofitting the limp home mode for their particular engines/memcals as well.(ie. Meaning they recalibrated it themselves) but still used the closest factory app in the first place.

later
Jeremy

JTB91RS

Thank you both for the quick replies. I am actually trying to get an AUJP memcal, as I think it would be the closest match to my setup, but they seem to be hard to find in junkyards around here, and GM now wants $160 for a new one (I think they are crazy ). I was hoping to broaden my search a bit since I am going to have to burn a custom PROM anyways. I might have found an AUJP, but if that falls through, I will continue to search for a 350 with a 7730 and hope for the best there (just so long as Limp and ESC are correct for a 7730 350, and only the PROM needs to be changed, I will be happy).

Thanks again,

John

Binder

Does anyone make a socket adapter to fit these things so we could burn them? I assume they're one time use so you would need a sourse for blank chips too.

JTB91RS

The PROM that GM puts in the memcal is a one time use as far as I know, so you will need to replace the PROM on the memcal unless you piggy-back, in which case you don't have to touch the memcal besides to plug it in to the new adapter. You can find chips and adapters here: http://www.moates.net/

I would recommend you get something like the G1 adapter so you don't have to hack up the memcal.

Binder

Are we talking about the same thing? The small "limp home mode" 16 pin chip? Just for the heck of it I put one in my burner and read it. Don't know what series chip it is but set for 2732A- 12.5 volts it seems to read it fine. Tuner pro shows it to have 4096 bytes. Seems to me if I had a sourse for blank chips I could burn new ones or what am I missing?

JTB91RS

My mistake completely. I thought that you were referring to either the main PROM or the memcal itself.

I am not really sure about the Limp Home chips. You should be able to replace it with a new PROM and a reprogrammed BIN, but from a quick search, it looks like 16 pin PROMs are obsolete (though I may be mistaken here).

Unfortunately, I have not yet come across any info on how to do this, nor any kits or adapters specifically for this. I believe that you are correct to assume that the chips would not be re-writable, so you would need a replacement if you wanted to make any changes. Best bet for replacing one would be to re-pin a newer EPROM to the old 16 pin socket, and restrict the addressing if the new chip is over 4k. I am willing to bet that it can be done, though finding pinouts of the old chip will likely be difficult, and I have no idea where to even begin looking for info on how to edit the BIN for it.

RBob

iTrader: (1)

The '7730 MEMCAL has 2 of the small 16 pin limp-mode 'chips.' These chips are actually a network of resistors. Used to program the redundent fuel device (RFD) for limp mode. On the DFI & ECM board sticky's is a picture of a '7730 MEMCAL.

As for the PROM in the MEMCAL, the new ones from GM are coming through with non-eraseable devices. Could erase them with x-rays, but there isn't a window for UV erasure. The MEMCALs that came in the cars have the EPROM devices in them.

RBob.

midniteplowboyy

iTrader: (1)

I think there crazy also. I bought one from my local parts store about a year ago for around $55.00, for an AC/Delco AUJP P/N-16151348 memcal.

HaulnA$$

Rbob, do you have any info on these x-ray erasable devices. I could'nt find any real good info and I have access to x-ray equipment and would like to experiment with these devices. You can PM me if you like. TIA

RBob

iTrader: (1)

The device should be a standard EPROM in a plastic package. Much cheaper. I can not recall where I read about it, but someone was dosing them to erase them. A net search brought up an astract here that contains some info:

http://ieeexplore.ieee.org/xpl/freea...rnumber=817033

"We have investigated the possibility of the use of X-rays to erase CMOS programmable digital ICs. In the experiment, microcontroller IC Z86 (Zilog) and 87C196KR (Intel) chips, were used. The repetitive pulsed electron accelerator URT-0.5 was used as an X-ray generator. It produced 7.6 Gy per minute (50 pps) at 5 cm from the anode on the axis, where the chips were placed. The maximum dose rate was 6.36 kGy/sec. The absorbed dose was measured using LiF-detectors. Tested chips with special program in their memory were irradiated until the information had been erased. A periodic control of the chip memory during the irradiation was performed. It has been found experimentally that CMOS PROM become free after irradiation with a dose of about 380 Gy, if it was wrapped up with 10-μm thick Al foil. The foil only connected chip pins. It is possible to make this erasure procedure with the same chip more than twice. Irradiation erased chips were successfully tested in the working device."

Not sure why the Al foil, it may have been for static discharges.

RBob.

HaulnA$$

Holy cow, I guess I can forget about playing around with trying to erase EPROMS with x-rays. It takes a huge 380 Gy dose to erase one. With the medical x-ray equipment I work on it would take a constant exposure at the maximum continuous rate for almost three days or the equivalent of about 2,500 chest x-rays. If you were to try it with an airport baggage screener, it would take about two weeks. Oh well.

DZcode

I purchased a new (350ci) memcal last year at http://theautopartsstore.com/
1 AC DELCO 16151348 ENGINE COMPUTER PROM/POWER CHIP
Total $59.51.

DZcode