Well I got my chips, my programmer, tuner cat, and turbo-link monitoring software for my 8746 ECU

1. I broke the plastic chip holder getting the chip out to read in my programmer.

2. Created BIN of original chip.

3. Used Tuner Cat to change some simple things. Removed VATS (before I have trouble with it). Changed rev limiter. Disabled EGR Diagnostics so my SES wouldn't come on all the time and thats it. Burned chip which wasn't easy. Didn't like my laptop. But finally got a successful burn.

4. Put new chip in plastic holder and rubber banded holder back together. Inserted chip. Plugged computer back into harness. Turned ignition on.

5. SES light flashes VERY fast and computer appears to be in limp mode.

6. Inserted original chip and get the same thing.

What do I do now?

 

Sounds like 2 things (maybe more). First when you broke the Plastic clip, how are you making sure that all the Eprom pins are connectiong with the ECM? Second You may have the eprom in backwards. Notch in Plastic peice towards netres and notch in chip towards notch in clip.

Also the 8746 doesn't have a rev limiter.

-Lars

 

I have my notches lined up. The pins are in the little grooves on the plastic piece. If I can get another prom how do I get the chip out without breaking the thing.

 

getting the chip out can be a little tricky you just have to have time, patience and good de-soldering skills

I have done few for people and after some practice you will get it

once all of the solder is removed the chip pretty much falls out

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1986 IROC 350 5spd
just installed a TPI from a 1988 IROC, 24# lt1 injectors,165 ECM MAF, custom sub frame
www.members.home.com/v8power/
GOT TOURQUE ?

 

Soldering? My original chip is socketed. I just don't know how to get that clip off without breaking it.

 

The TBI proms can be a real pain. Definatly not something I like taking in and out, but just be patient. Another tip is to bent ALL of the pins on the prom, SLIGHTLY inwards, that way when you insert it back into the socket it will have some resistance going in and should help lock it in. The little black plastic holder does wonders huh?

I would highly recommend getting a new holder(from a junkyard probly, they are out of production now..)
Or try to "rig" something up to help keep the prom in its correct place..


Brendan

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1987 IROC-Z L98,SR,EB 6085's,LPE 219/219 Cam, Crane 1.6RR, EB TPI Base, 58mm TB, Stock T5, 30lb SVO, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, Aluminum DS, 94 Disk Rear, Adjustable Prop Valve, Precision 3.73 Gears, Weld in Sub-Frame Connectors, Hotchkis LCA's, KYB Shocks/Struts, Poly Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm, Big stereo, 730SD Conversion.

To see the ROC, Check out the webpage Here

 

I hated the darn plastic piece the first day I took out my eprom. Next day I ordered a few zif sockets and now I just plug and play. I'm working on making it super low profile so I can fit my cover back on and then I can have a tech article about it. It's relatively easy since you don't HAVE to solder each of the zif pins onto the board. Just like 4 at each end holds it real good.
Definatly sounds like the eprom is in wrong. Why are you having so many problems programming the eproms? I have yet to have a bad burn except on one which I left in the "cooker" for too long, came out nice and toasty and didn't want to do ANYTHING.

 

Jon, the classic "more is not necessarily better"? Especially when it comes to erasing an eprom.

What needs to be figured out, is how to use a Flash Prom instead for those 747s and 746s. Maybe a ROMless ECM?

 

What would the eeprom number be for a 27c256 eprom?Will the pocket programmer erase an eeprom?

 

The AT29C256 is Flash Prom that is a direct replacement for the 27C256 (used by SD cars), and if you write to the top half, you can also use it for 27C128s (used by MAF cars). And it can be reprogrammed with the Pocket Programmer and doesn't need to be erased by a UV Eraser.

It's only a buck more than a comparable 27C256, avoids having to use a UV Eraser and can be re-written to many more times than an regular eprom like the 27C256 - though a Flash Prom still has a limited number of re-writes.

 

Jon, If I buy another 8746 ECU, how much would you charge to put a Zif socket in for me. My soldering skills are matched only by my chip burning skills. This way I can still have the original that I can put in after I am done playing with the programming. As easy as this was to screw up I can't keep doing this every time I want to make a change. Since it may take me 50+ chips to get it the way I want. Probably 400 chips once I drop my AFR 350 in there. ZIF is the only way to go.

 

I don't think you hurt the ECM you probably are not getting good contact on all the pins is all, I've done it several times.
Just make sure you use another good holder and be careful not to bend any pins.
The rapid flashing means just that, not a good contact.

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Chronologically challenged. But still kicking!
'92 CAMARO RS
305 TBI 5/spd (now TPI)
B4C Alt.
Cam change:TRW 198/210 ,450/.460 114 LSA
Stock TBI manifolds
'85 IROC Ex.
14.94-92.00 mph
SPDC base and "350" Vortec coming soon!
'69 camaro-BB/Lenco,1050 dominators, /Pump Gas/no drugs 8.97-150+/3200lbs.
SoCal Thirdgen F-Bodies

 

I found it impossible to find one of these clips. None of the junkyards around here will even sell me a chip without buying the whole ECM.

 

http://car-part.com
not carparts.com, not carpart.com
They have a listing of a BUNCH of places, mostly all used or remanufactured.

 

Yeah I just got my ECM from a junkyard listing on that site $25 + shipping.