Obd1 Swap To Obd2 Some Questions
 

ok so i was moving right along with my 97 interior install when i realized that my car nolonger will start. it just cranks with all the 1997 electronics in it, w.t.f. so i started checking around and i found that the 1997 obd2 system has a crank sensor and the 1995 obd1 system dont.

ok now im getting frustrated with this whole thing, when i change the front wiring that means that i rewired the whole car from front to rear!!

what a pain this is. i seen someone else on here did the same conversion and i was wondering how it went?

did you also have to change all this wiring? please let me know what else i have to do as im tired of ordering from out of state for all these parts.

now i wont have this wiring till thursday again, maybe by nextweek monday it will finally run again and be about finished.

Re: Obd1 Swap To Obd2 Some Questions
 

no takers here?

Re: Obd1 Swap To Obd2 Some Questions
 

Did you change the engine harness? If so, Why? I would think you would leave the engine harness alone and just change the dash harness. :confused:

I've never done it, though so I'm just guessing. An OBDII car has many different sensors under the hood that an OBDI car doesnt have. You cannot just plug an OBDII engine harness into your OBDI car.

Re: Obd1 Swap To Obd2 Some Questions
 

the problem is that i have to change the engine wiring harness, i didnt do that yet and then the whole car will be obd2.

man this sucks, this was alot of work

Re: Obd1 Swap To Obd2 Some Questions
 

Why would you even want to switch? Only get easier diagnostics, its not worth the trouble though.

Re: Obd1 Swap To Obd2 Some Questions
 

Why do you "have to change the engine wiring harness"?

Re: Obd1 Swap To Obd2 Some Questions
 

i switched because the dash in my car was from a 1997, and the outside looks like a 2001 camaro ss. the dash would not work unless i put the 1997 wiring harness in there and the 1997 cars were obd2.

since i already had all the 2001 interior it was actually cheaper for me to make that all work instead of buying all new 1995 interior, plus it looks so much better.

and the only reason that the engine harness is different is because the obd2 cars have a crank sensor and the obd1 cars dont, therfore when i crank my car over i get no fuel or no spark because the computer is looking for that crank sensor that isn`t there.

when i get the rest of the wiring harness and install it my car should, ( better ) start right up.

and also theres something else in the computer of that 97ss that i got all the parts from but it actually has 345hp instaed of the 305hp.

i cant hardly wait any longer to get those parts, i should have them sometime this week hopefully.

dont worry, i have been taking all the install pics and will post em on my car domain as soon as i get this project finished :D

Re: Obd1 Swap To Obd2 Some Questions
 

So then I assume you are going to install a crank sensor. How do you plan on doing that?

Re: Obd1 Swap To Obd2 Some Questions
 

what do you mean how do i plan on doing that? it should juz bolt right in place right? then the new harness will have the plug and wiring to plug it all in.

Re: Obd1 Swap To Obd2 Some Questions
 

NOPE! TO install a crank sensor, you will have to change the timming chain, timing cover, and Opti to the 95-97 style.

I'm a little confused, did you change to an OBD II computer yet? If not, it should run. Also, an OBD II car will run without the crank sensor. It's only there for misfire detection. The OBD II cars also have rear O2 sensors and a different Knock sensor.

Did you change the steering column? If so are you using the original ignition lock for your car? If not the Pass Key system is seeing the wrong key and not letting the engine start. In this instance, I beleive it cuts the fuel pump. Check to see if you have fuel pressure or spark while the engine is cranking.

While I haven't done this conversion, I have looked into it. So far I haven't found anything in the dash to require switching to OBD II.

Good Luck

Re: Obd1 Swap To Obd2 Some Questions
 

sounds like you have your hands full there. Good luck

Re: Obd1 Swap To Obd2 Some Questions
 

well i have changed the whole wiring harness from the firewall to the rear taillights and everything works except the engine itself.

see my car is a 1995 car and even with the original pcm the car still doesnt start. i used the 1997 bcm wich has the anti theft module built right in and i had to use the vin number to get the right vats code and the key fob, before this the car wouldnt even crank over, now it cranks and the security light is off but it wont start with either pcm.

now i did notice that all the wires are different on the dash wiring plug that goes to the pcm, so the only thing i can think of is the harness is pinned wrong.

it would be easier for me to get the harness from the parts car because i know then that it has to start, it doesnt have a choice because the 1997 car ran very well and that harness is all i need to complete the swap.

as far as the o2 sensors, i probably wont hook those up and the crank sensor, i guess im gonna have to buy a timing cover and the hardware to install that crank sensor on my engine, now the knock sensors im gonna have to change also.

anything else you can think of? please let me know what you think.

Re: Obd1 Swap To Obd2 Some Questions
 

Check this page it has a lot of good info..
Note the timing covers, crank key, timing gear pics, and other info:
http://www.malcams.com/legacy/misc/autorebuild.htm
If you have a vented opti [you say that you do, even tho engine is supposedly from a 94 F body] then the opti and timing chain should be OK, as the cam should be drilled and have the longer pin, and the timing set should be OK already..
That motor has aluminum heads right? I see the iron head [caprices etc] motors had vented opti's in 94..
The 96-7 timing cover has the CPS in it so you need that cover GM 12552427.. and the balancer hub is different for a 96-7, GM 12550097 [shorter?] You need the slotted wheel for the CPS also.. maybe someone with a 96-7 can provide more info about that for you I never worked on one, but do know the crank key and the timing cover are different..
Like posted above, I believe it should run with out a CPS?[not positive, but I have read that also]
I have a 94, and the PCV hose is a horseshoe shape that goes right back into the intake manifold by the PCV on the drivers side.. 95 and later it goes to the front at the throttle body.. [might help you identify the year of engine]

Re: Obd1 Swap To Obd2 Some Questions
 

ok, i was looking at my registration and my car is a 1994, sorry about that.

i contacted the original owners of the car and also the guy that did the swap and they both say that the engine is the original one. now by looking, the engine looks like it has never been removed.

the title for this car also shows 72000 original miles as did the old instrument cluster.

im still a little confused about the odb1 to obd2 pcm though, the pcm,s are completely different so i dont see how they could interchange with each other wothout changing the wiring.

another thing i was gonna look at was possibly after i install the new engine harness instead of the cps sensor setup, i was gonna contact msd and see if they have a system that will elminate that cps so i dont have to change the timing cover and such.

thank you guys sssooooo much for all your input here, i really need it, i am so close but still far enough away from getting this thing done but i think it will be really sweet when she`s finished.

how can i tell if it has a vented opti or not?

i know that we all love to read the threads, but if it would be easier to explain this, feel free to call my cell anytime, my name is jim and my number is
734-377-8436.

thanks again.

Re: Obd1 Swap To Obd2 Some Questions
 

The PCMs are not that different. The physical connectors and most of the wiring is identical. You don't need to rewire anything in the engine compartment. You don't need to put in a crank sensor. The F-body does not use it for any spark control, just misfire detection. Your engine will run without one. Your 1994 engine will not have an EVAP vacuum switch or rear O2s. Those are the only other device differences in the PCMs. You could use either PCM and it should run fine. There are people that swap back and forth from OBD-I to II for testing purposes and do nothing else than swap the PCM itself. You might get some trouble codes with the OBD-II PCM on an OBD-I engine, but you should be able to get most things programmed out, if needed.