Difference between P08 and P28

[FR33K]

Im currently running an OBD1 b16a engine with a PO8 ECU.

Im doin a bit of research so I make sure i get the right ECU to suit this engine.

Now ive been offered a virgin P28 ECU and i was wondering if this is the correct one ?

As after doing a bit of research ive discovered that (and please correct me if im wrong):

P28 = single cam vtec - U.S. model.(can be chipped to work with a B16a)

P08 = single cam - jdm models (same as the p28, also can be chipped to work)

therefore, buying a P28 ECU for my b16a would be a waste of money ?? when i should just get my ECU chipped ? (i havent checked if it has been yet)

and the only other difference is that using a P08 ECU on an OBD1 b16a - it needs to be chipped to run the 4 wire O2 sensor ??

which leaves me with another question.. if my ECU isnt chipped... how could it be running the o2 sensor (unless its a single wire o2) - something ill have to figure out when the weather cools down !!

The other difference between the 2 is that po8 has no knock sensor ? and p28 does ?

I guess the bottom line is - what STANDARD ECU should I be getting to suite my engine..

sorry for the long list of questions *confused* :thumbsup::thumbsup:

[ECU-MAN]

neither ecu is the correct ecu for the B16A, however they can both be made to run the B16A happily with the correct modification or ROM. they both dont support knock. the P08 and P28 will need to be modded to handle the 4 wire O2

dont waist your time/money looking for another ecu

btw the correct ecu would be P30

[FR33K]

so u think i should just chip mine rather than sell and purchase a p30 ?

coz its knocking like crazy now.. espeically on a hot day with the a/c on..

i know this isnt a wtb thread but generally how much would i be looking at for a p30 ?

[FR33K]

and also, if my ECU hasnt been chipped... engine light should come on for malfunction of o2 sensor ? (which it isnt)

[ECU-MAN]

all depends on what the setup is
if your running a stock p28 or p08 on a b16a then yes it will knock as the fuel and timing maps are ment for a different engine.



do you know if your ecu is stock ?

[ECU-MAN]

and also, if my ECU hasnt been chipped... engine light should come on for malfunction of o2 sensor ? (which it isnt)

not true

the stock p08 will look for a one wire o2, it will see the signal coming from the 4 wire o2.

4 wire o2 still pumps out a signal if you dont hook up the heater

[FR33K]

thanks for your help - i guess opening up my ECU would be a good start :)

just wanted to try and get an idea of what it is and what it should be.

[ECU-MAN]

if you can open the ecu and take a picture of the component side.

post it up and then I can tell you what your next step should be.

[AsH_]

i have a b16a with a p08...

my ecu fried so i am getting another p08...

is there a disadvantage of running the p08?

[FR33K]

as ECU MAn stated - it would be fine if it was chipped with the correct ignition and fuel maps. however, as a standard ECU it is tuned for a D-series SOHC Vtec engine i.e. not for b16a

you also have to check which o2 sensor you have (1 wire or 4 wire)

[ECU-MAN]

if its an OBDI or OBDII B16A it will have a 4 wire o2, only OBD0 B16A had 1 wire O2 ( and they had two of them )

[FR33K]

ok we are finally getting somewhere...

opened up the ECU and it has been socketed and chipped.

chips says its a Mugen ITR p30 5000 Vtec/8400 rev limit.

now looking at these 2 sites.. its not matching either "mugen" chip so i dont know where it came from. i guess it has been customised.

http://www.jdmshit.com/ecu/index.html
http://ag-engineering.net/ecu_list_obd1.htm

either way, since it has been socketed, anyone know where i can get a standard b16a chip so i can replace it - or any other chip they recommend ? and are chips interchangeable between PO8, P28, and P30 ?

heres the pic..

http://img.photobucket.com/albums/v110/FR33K/chip.jpg

[Edgeauto]

At least your not running the D series maps. You will still need to post a high res picture of your ECU to see it has 4 wire O2 sensor support.

[FR33K]

here we go.. what exactly are we looking for ?

its the largest photobucket would let me upload so you might need to save pic n zoom in..

http://img.photobucket.com/albums/v110/FR33K/ecu.jpg

[Edgeauto]

You will need to take a pic of the other side of the board too. That is also a AT ECU.

[FR33K]

ok.. a shot of the back is shown below. cant really see any other areas of the ECU that have been tampered with - other than the big chip.

so since this is an auto ecu, basically i should scrap it and buy a MT p30 ??

OR can this one be converted somehow?

http://img.photobucket.com/albums/v110/FR33K/scu2.jpg

[Edgeauto]

Looks like it can support a 4 wire O2 sensor. It can be converted to MT easily but is that rust on the board. PM ECU-MAN he should be able to help you out.

[FR33K]

ok thanks ill wait for him to respond.

In regards to the rust.. is there something "safe" that i could clean it with ?

[ECU-MAN]

yes that ecu needs to be converted to MT have the o2 heater support added and a chip for b16a.

that rust is not a good thing.

PM me if you need help getting this ecu ready for your engine.

[ProECU]

If you have access to a soldering iron you can do the conversion yourself easily. Will take you 15minutes and less than $30 to do.
If you get charged more than that look elsewhere.

O2:
simply add a SMT version of the 2N4401 (general purpose NPN switching transistor) to location Q15 on the underside of the PCB. Part is available from Jaycar or similar for a few bucks.

Auto to Manual:
remove rp17 remove rp18 add a jumper to rp18