ls vtec integra obd1, chipped p28 ecu, i chipped myself..

i started it, and it ran, but only revved to about 4k rpms. with a solid cel. so i cut the j1 jumper, and the car runs ok, but idles at 2k rpms.. and now after i cut j1, there is no CEL.

i dont get it.

 

the same exact thing happen to me; 4k rpm, solid cel, but I didn't cut the jumper please tell me what that would do?

 

cutting the jumper will bring the ecu back into stock mode. by passing the external rom.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Acura_I-RS &raquo;</TD></TR><TR><TD CLASS="quote">ls vtec integra obd1, chipped p28 ecu, i chipped myself..

i started it, and it ran, but only revved to about 4k rpms. with a solid cel. so i cut the j1 jumper, and the car runs ok, but idles at 2k rpms.. and now after i cut j1, there is no CEL.

i dont get it.</TD></TR></TABLE>

There are five possibilities:

1. The chip was installed backwards and that killed it.
2. The .bin file on the chip is corrupt.
3. There is a problem with your soldering
4. Your 74HC373 latch is bad.
5. If you are using a 28 pin socket, it is possible that not all of the ROM chip pins are making contact.

 

well, i did desolder the 74HC373 latch and resolder it into the new ecu, i tried making a new bin, made sure the chip was in right every time, as far as i can tell, soldering looks good.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Acura_I-RS &raquo;</TD></TR><TR><TD CLASS="quote">well, i did desolder the 74HC373 latch and resolder it into the new ecu, </TD></TR></TABLE>

That might have overheated it. Do you have a Radio-Shack near by? They should have a 74HCT373 on the shelf. Can you check your solder joints with a DMM?

 

radio shack didnt have the chip there.. i already checked.. thats why i reused it...

 

I'd go get another hc373, it is likely you burnt it desoldering it.

 

what exactly is the function of that chip?

 

ok, i got another 74HC373 chip, is there anythign else i shoudl do when changing this chip out then?

 

Just take to old one out and solder the new one in, be sure not to tear any traces. I think its just a gate, and tells the ecu where to get data on the eprom, not sure though.