OBD2 to OBD1 LT1

[Rocko350]

put the motor and the rans in to begin with. Can you tune or are you able to tune the 96 computer? f not. Put the 94 ecm into the car. Repin harness and install the 94 knock sensors. The obd2 port under the dash will need to get changed to the obd1 connector so you can tune and datalog and diag if needed the new engine controller if needed. Tach ouptu is easy. The tach low res periods are adjustable in the obd1 computer. Obviously the crank sensor pigtail isn't used. neither is the AIR. the 96 has a fuel tank pressure sensor the 94/95s dont have. Un pin those from the ecm. Use www.shbox.com for wiring references. Reuse the 96 harness, coil, ignition module. Have a set of the injectors cleaned and flowed. There are plenty of people tha have done this before you. Look also on www.impalassforum.com

[NomakeWan]

Why not convert to a 95 pcm? would be less wiring, if any.

That's...exactly what he's doing. The PCM is the same; it's the program that's different.

95 PCM uses the dual signal of the knock sensor?

No. Only the OBDII PCM does, which is why it's a different part number.

put the motor and the rans in to begin with. Can you tune or are you able to tune the 96 computer? f not. Put the 94 ecm into the car. Repin harness and install the 94 knock sensors. The obd2 port under the dash will need to get changed to the obd1 connector so you can tune and datalog and diag if needed the new engine controller if needed. Tach ouptu is easy. The tach low res periods are adjustable in the obd1 computer. Obviously the crank sensor pigtail isn't used. neither is the AIR. the 96 has a fuel tank pressure sensor the 94/95s dont have. Un pin those from the ecm. Use www.shbox.com for wiring references. Reuse the 96 harness, coil, ignition module. Have a set of the injectors cleaned and flowed. There are plenty of people tha have done this before you. Look also on www.impalassforum.com

Why the 94 computer specifically? Either the 94 or 95 computer will work just fine. The computer is the same--it's the program that's different. Also tuning the '96 is a major PITA, which is probably exactly why he's doing this swap. At some point in the future it won't be that way, but for now, it is.

[Rocko350]

That's...exactly what he's doing. The PCM is the same; it's the program that's different.


Pcms are not the same. Im kinda tired of explaining this.



Why the 94 computer specifically? Either the 94 or 95 computer will work just fine. The computer is the same--it's the program that's different. Also tuning the '96 is a major PITA, which is probably exactly why he's doing this swap. At some point in the future it won't be that way, but for now, it is.

reread first post. It is what he has to install.

[NomakeWan]

reread first post. It is what he has to install.

I suggest you take your own advice. It states any OBDI PCM (because they’re the same), with a program from a ‘95 to handle the PWM TCC.

The only difference in OBDI PCMs is between Corvette and non-Corvette (the Corvette ones added additional silicon related to OBDII testing). The year does not matter, and since he doesn’t care about the OBDII stuff, neither does Corvette vs non-Corvette.

[Rocko350]

I suggest you take your own advice. It states any OBDI PCM (because they’re the same), with a program from a ‘95 to handle the PWM TCC.

The only difference in OBDI PCMs is between Corvette and non-Corvette (the Corvette ones added additional silicon related to OBDII testing). The year does not matter, and since he doesn’t care about the OBDII stuff, neither does Corvette vs non-Corvette.

Why would he need the pwm trans control?

[NomakeWan]

Why would he need the pwm trans control?

You're right, he wouldn't--it's only an issue on the auto trans. So actually he can do whatever, good point. Even less of a reason to be picky about 94/95.