twinturboy

I have a question regarding the stock 93 ecu. I was previously using a pettit modified ecu, but recently, due to some wiring problems, it has shorted out a few circuits inside. I have fixed the wiring problem, but the ecu does not work anymore. It does not give a check engine light with the ignition switch, and does not give any codes. Also the car does not start with this ecu. I have a stock ecu that works perfectly, and was wondering if it was possible to upgrade it using parts from the pettit ecu. Is there a rom chip that I can take out and put in the stock ecu, which contains the upgraded fuel maps? Can anyone tell me specifically how the pettit ecu is upgraded, and the differences between it and a stock ecu. I would appreciate any help. Thanks.
Aneel
93 touring
orlando, fl

FormerPorscheGuy

If the chip in your pettit ecu is fried then there is nothing that you can do except through it away. I hate to be the bringer of bad news but there is nothing you can do about it except by a new one.

DaleClark

iTrader: (55)

I do believe the Pettit ECU has a daughterboard inside that's added to a stock ECU - that has all the code and the like.

Have you verified the ECU is actually blown? That's pretty uncommon - normally you'll pop a fuse before any damage is done to the ECU. They're quite hardy.

Might also call Pettit and see what they'd charge to swap the guts from that ECU to a good, stock ECU.

Again, I would double-check the ECU is actually the culprit. They're VERY hardy.

Dale

twinturboy

I'm pretty sure the ecu is damaged. My passenger-front wheel was rubbing against the front harness under the fender liner, cut about 10 diff wires and shorted them all out. Funny how no fuses blew though. Before finding this out, the pettit ecu was damaged, along with the spare stock ecu I had. I found the damaged harness, repaired it and still both ecu's didnt work. I recently bought another stock ecu for 60 bucks which works, and plugged it in and everything is back to normal. Now I was wondering if I could just take out the chips from the pettit ecu, assuming they are still good, and put them in my stock ecu. As long as I knew exactly what needs to be done, I have no problem soldering in new chips, etc. I will have to take apart both ecu's and see what the difference is. I just need to know what exactly I need to take out of the pettit ecu and put in the stock ecu. Thanks.
Aneel

twinturboy

I dont think the rom chips would be damaged very easily. Even if some of the circuits fried inside the ecu, the rom should still be good i'm assuming.

DaleClark

iTrader: (55)

I've seen pictures a long time ago of the "guts" of a modded ECU - they put a daughterboard in there that has the new ROM program.

Dunno how easy it is to swap - hopefully it just plugs into a socket. I've heard of ECU's where the ROMs were soldered in - they had to be removed, and replaced with a socket. If so, that gets kind of involved. If it simply plugs in to a socket, that's a piece of cake.

Anyhow, it's well worth taking the two apart and seeing what you find out. If it looks like there's no way in hell to swap it, I'd just call Pettit and see what they would charge to swap it over.

Good luck!
Dale

bureau_c

Unfortunately, they're soldered in the stock ECUs...part of the mod that Pettit performs is socketing the microp and the external EPROM. The daughter board goes where the microp used to sit.

I hosed a stock ECU trying to do this...the damned microp was wedged so tightly in there that I haven't been able to get it out without destroying everything. I don't know if mine was unusually bad, or if Pettit's desolderers know or have something that I don't.

To address another comment...I don't know how hardy those ECUs are. I have a stack of dead ones right next to me that I tried (and failed) to resurrect.

jds

Matt RC-Racing

Twinturboy.
Send me a email off list.. I may be able to help you.