here's the situation.
i bought a 94 ex (coupe) with a non-original d16z6 motor and tranny installed.
i see a red wire connected to the vtec solinoid going into the interior.
i then go look at the ecu and see P72!!!!!!!!!!!!!!
is it even possible to run p72 ecu with z6??
dont they have to rewire some wires to run a p72??
my speedo dont work? is it cause the ecu??
is vtec working?? i think it does...but im new to civics...

 

the red wire going from the solenoid is the vtec wire. the harness your using must not be a vtec harness. running a P72 should be okay, not to sure on that one. speedo might not be working cause of the speed sensor, check it out. i think the plugs are the same from a P30 to a P72 so it might not be the ECU. correct me if im wrong everyone. im still learning myself. good luck!

 

I'm really confused, the EX coupes came with D16Z6s right from the factory, so I don't know why someone ran their own wiring for vtec. You want a P28 ECU for a Z6, the P72 is for a B18C1 (GS-R/JDM SiR-G), it will run rich with that ECU. It wont have any affect on the speed sensor though.

 

yea,
he had a gsr swap in the process when he sold me the car....i think he took the p28...
is it possible he got the p72 chipped to run d16z6 specs???
is it possible he hardwired the vtec to the p72??
okay, and last but not least....can the ex harness fit the p72??
im a noobie

 

obd1 civic and integra harnesses have the same connectors at the ecu..
you could pop the cover off the p72 and see if its chipped or not..
its possible he ran the vtec wire straight to the ecu..
maybe he used a nonvtec harness? i couldnt tell you for sure tho..

i have a p28 for sale.. or ill trade you for that p72 if its not chipped..

 

That potentially explains a lot

Possible yes, just unlikely. It definately can be done, but its not common and you'll throw a knock sensor code unless you tell whoevers chipping it to disable the knock sensor (the Z6 doesn't have a knock sensor and the stock p72 will look for it)

Yes
Yes, all OBD1 Honda ECUs use the same plugs and pinouts. Meaning that any civic, integra, accord, prelude ECU will plug in.

 

i'll note you if its not chipped

 

i see
thanks guys, this is a lot of help.
ONE MORE QUESTION!!!
if he hardwired vtec to the harness,
which wires do you need to cut into???
i see two red wires, and one is connected but the there's another red wire that is just hanging there...i think it came loose....do you guys have any clue what it might be??

 

your vtec may not work if your speedo isnt working..
one of vtec's requirements is vehicle speed..

you can refer to this page: http://technet.ff-squad.com/wiring.obd1.htm
it had the obd1 pin outs..

 

Well provided the original harness is still there should never have been any cutting and splicing, it should just be a plug and play setup. Take a couple of pics of the harness and post them, it would help a lot, one at the shock tower, and one at the vtec solenoid.

 

aight, we'll see what i can do

 

pics taken, will post soon

 

back of ecu

 

vtec solinoid

 

okay, then out of the firewall, there is two wires (i am holding one, the other one you can see) that is cut off and taped....what are they for??

and the other two red wire you see, one is the one connecting the vtech solinoid. the other is the starter ( i think)...

 

this picture is just to shows the wired vtec routing to the inside of the car..
the other red wire is a wired starter wire ( i think)


this picture is just to show that one of the red wires are not hooked up to the ecu....
which one is it?? can you guess from which one is already connected?? if so, which ecu wire hooks up the non connected wire??
and another noob question...what is those two blue clips for??

 

help!?!?!

 

help guys, i thinnk that blue clip means its a 6generation harnes...
i somehow heard that its supposed to be grey if its the 5g harness..

 

looks to me like they for some reason took the vtec harness out, or just didn't have one like they should've had with the EX.. It looks like they tried to wire some wires in for the vtec which they didn't even have to do since you have an ex all they had to do is run 2 wires from the shock tower plugs to the vtec solenoid and vtec oil pressure switch. And also, geebs is correct about your vtec isn't going to work if your speedometer isn't working, honda did this so that you can't just sit and rev your car up and have vtec come in and such.. check your speed sensor and make sure yours isn't messed up or see if it is.

 

The Vehicle harness is an EX harnes, the vtec wiring is still there, its just hacked up at the ECU. It looks like a non vtec engine harness was used though. Either fix the factory wiring at the ECU and get an EX/Si engine harness (ideal solution) or wire the vtec solenoid to pin A4 and the vtec pressure switch to D6.

 

wow badass wiring job

 

true, i'd fix the wiring on the ecu harness asap..

 

It worries me that someone who would wire VTEC like that was going to do a GSR swap.

 

lol true that man..

 

ok ok.....
so, to make it simple........can i just get an original ex harness WITH an p28 ecu
and hook it up???? and get a new speed sensor????
do you think that will solve the problem??

also, if possible, can you tell me what the spliced wires are???
i know the color of one is ORANGE, but what does the orange one do??