My buddy just picked up a chipped P28 ECU, but something is seriously wrong with it when you jump it to read the chip. A check engine light is on and the car won't rev past 4K. I took it apart, it doesn't have any of the extra capacitors on it, but I've heard they are optional. I have successfully chipped my own computer, but not quite sure what to do with this one. I'm hoping that someone can steer me in the right direction. I've been told to desolder the socket and gate and install new ones, but I have no idea how to desolder those 20+ pin connectors, limited to what I have in my tool box, and there's not a lot of electrical stuff in it. Please help.

Eric

 

Bad chip, bad connection somewhere. Its most likely something very very simple.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoredRec &raquo;</TD></TR><TR><TD CLASS="quote">My buddy just picked up a chipped P28 ECU, but something is seriously wrong with it when you jump it to read the chip. A check engine light is on and the car won't rev past 4K. I took it apart, it doesn't have any of the extra capacitors on it, but I've heard they are optional. I have successfully chipped my own computer, but not quite sure what to do with this one. I'm hoping that someone can steer me in the right direction. I've been told to desolder the socket and gate and install new ones, but I have no idea how to desolder those 20+ pin connectors, limited to what I have in my tool box, and there's not a lot of electrical stuff in it. Please help.

Eric</TD></TR></TABLE>

When that happens, it could be one or a combo of these problems:
- eprom had a bad burn
- eprom is installed incorrectly
- eprom is not making complete contact with the socket somewhere
- the socket was soldered in shitty
- there's capacitors missing that are needed and or J1 isn't jumped.

can you snap & post some clear digital pictures of this problamatic ecu? mainly a top view of the ecu with the cover removed exposing the motherboard. It would help to diagnose the problem...

 

I don't believe it's the chip, it works fine in my car. I'll try adding the missing capacitors and see if that helps. I would take a picture of it, but I just sent my camera off to get warranteed, the screen is all screwed up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoredRec &raquo;</TD></TR><TR><TD CLASS="quote">I don't believe it's the chip, it works fine in my car. I'll try adding the missing capacitors and see if that helps. I would take a picture of it, but I just sent my camera off to get warranteed, the screen is all screwed up.</TD></TR></TABLE>

well then, if the P28 works fine in your car, but crappy in your friends car, somethings definitely up with your friends wiring or ignition system....perhaps something isn't plugged in all the way (distributor perhaps)...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Katman &raquo;</TD></TR><TR><TD CLASS="quote">

well then, if the P28 works fine in your car, but crappy in your friends car, somethings definitely up with your friends wiring or ignition system....perhaps something isn't plugged in all the way (distributor perhaps)...</TD></TR></TABLE>

No, I meant the chip is good. Just added the capacitors, didn't help. I don't know if this is normal since I'm still new to chipping computers, but the car will run jumped without a chip in it. Any advice on desoldering?

EDIT:
Ok, don't know if this is gonna give me problems, but apparently this computer he got is a p28-a52...an automatic ecu. Is this an issue, or can I just rearrange the components on his ecu to emulate the ones on mine?


Modified by BoredRec at 5:23 PM 9/27/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoredRec &raquo;</TD></TR><TR><TD CLASS="quote">

No, I meant the chip is good. Just added the capacitors, didn't help. I don't know if this is normal since I'm still new to chipping computers, but the car will run jumped without a chip in it. Any advice on desoldering?

EDIT:
Ok, don't know if this is gonna give me problems, but apparently this computer he got is a p28-a52...an automatic ecu. Is this an issue, or can I just rearrange the components on his ecu to emulate the ones on mine?

</TD></TR></TABLE>

As long as the program thats burned onto the eprom chip is a 5speed program, it doesnt matter if the P28 is Auto or not, the program on the chip will dictate the 5spd or Auto factor. You technically don't need to change around anything else besides putting a 5speed chip on the P28 for it to be a 5speed P28...