i have a question i had an auto p28 and i went to convert to obd1 and when i wanted to check if it starts it didnt...it didnt get spark or the fuel pump wasnt priming so...i took everything out and wanted to restart...but i opened the ecu and above the auto/manual resisters there is no rom...theres just a space where the rom should go...and the numbers 27256 are there.....is this normal?? When i opened the ecu this is what it looked like




Modified by hotimportcrx at 8:03 PM 7/23/2005


Modified by hotimportcrx at 8:04 PM 7/23/2005

 

I doubt that is normel, looks like someone Socketed it, and someone took the socket\chip. and rid the p28.

 

 

PM DrDisco69 he maybe able to help you.

 

that ecu was never socketed. that is how a stock obd-1 ecu looks. you have to put a socket where 27256 is and a chip in the 74hc373 socket. that ecu appears to me to be in new from the factory condition. it hasnt been chipped or anything. it should work just fine.

 

whut exactly are you trying to do?

if u want to use the p28 sohc rom, its built in. convert it to manual? you can do that too.

but to run a new rom altogether, u need to add everything thats outlined in that lot.

 

pgmfi.org

Has really good knowledge on these sort of things.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fobtions &raquo;</TD></TR><TR><TD CLASS="quote">whut exactly are you trying to do?

if u want to use the p28 sohc rom, its built in. convert it to manual? you can do that too.

but to run a new rom altogether, u need to add everything thats outlined in that lot. </TD></TR></TABLE>

im trying to figure out y my car wont start ....no fuel or sprak...and im trying to see if a stock ecu is suppose to look like this inside..thinking maybe the ecu is bad...

 

No, the other people are right. Most OBD0 ecus used an external rom, but almost all the OBD1 ecus used an internal rom. All the maps and things were stored in another chip on the board. The whole deal with chipping the OBD1 is that you add the rom and all the circuitry to make the ecu use the external rom instead of the internal one.

Read up on http://www.pgmfi.org if you want to know more. As far as the car not starting, you still may have a bad ecu, but even with a bad ecu, the car will usually start under limp mode. I would focus on other things, like the sensors in the distributor, fuses, etc. Good luck!

 

found out the problem car was getting no spark and no fuel because the main relay went and the distributor was bad....thanks anyway for the help.

 

FYI, some OBD1 ECU's came "chipped" from the factory, they must have decided the program needed an update.

 

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

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">I would focus on other things, like the sensors in the distributor</TD></TR></TABLE>

I am teh win...