93 swap obd2 motor

[Joker Z28]

A friend of mine who is too lazy to join the forum has a problem/question.


He has a 93 Z28 A4 which motor was getting ready to die.

He bough a motor from a 97 Z28 M6 with 72K miles which was running fine.

In the middle of the procces as both motors were out on engine stands he wanted to move over all of his stuff cause he had new opti, water pump, belt ect. ect. but because of the 2 different optisparks his wiring harness doesnt fit the 97 motor. He is on the way to pick up from the guy the computer and wiring harness, he will sell the computer because it was an M6 and wouldn't work I guess but he going to have a 97 motor with 97 wiring harness. What kind of problems would that cause if its with a 93 computer?

[mapolley07]

IIRC, the M6 PCM *SHOULD* work because in '93 the A4 was the 4L60, not the 4L60E, meaning it was not controlled by the computer at all. The M6 PCM should not be a problem with a '93 transmission.

A full swap from OBD1 to OBD2 will be necessary including all the sensors, the OBDII connector, extra 02 sensors, PCM, etc. Honestly, I would try to make the '93 opti and sensors, harness, etc. work with the 97 motor by removing or not using the OBD2 sensors and electronics. I think it can be done, but don't trust me on that.

I have never messed with an LT1 for the record. I own a '95 3.4 'bird and just have been amassing research and knowledge for a future V6 to LT1 swap. Someone correct my info if wrong.

[Chris]

Are you sure he didnt join because someone was asking this exact same stuff.

He cant use his opti on the 97 motor. He will needthe 97 harness and computer keep it all and use it.

[mapolley07]

Are you sure he didnt join because someone was asking this exact same stuff.

He cant use his opti on the 97 motor. He will needthe 97 harness and computer keep it all and use it.

Okay, like I said, I don't know much about the LT1, just learning right now. What about the 97 motor makes and earlier opti not fit? I wasn't aware of any differences in optis other than vented vs. nonvented

[Chris]

Not trying to give ya shit just seemed odd 2 people would have the same problem lol.

Your opti uses a spline that is keyed to the opti. the Vented ones use a long Dowel pin that drives it. I think the wiring connectors may be different as well.

[Chris]

Bookmark this webpage. Almost any information you will ever need on lt1s its a lifesaver

http://shbox.com


http://shbox.com/1/93-94_opti.jpg
http://shbox.com/1/opti_back.jpg

[Fastbird]

He will needthe 97 harness and computer keep it all and use it.

No he won't.

Drop the 97 motor in. He can NOT use his opti on the 97, that is a fact. If you examine the opti harness though, you'll see that the late style harness will mate with the 93 wiring harness in the car, you just have to trim one alignment tab off the end that plugs into the cars harness. I know because my car has this. Use the 93 manifolds because they're designed to work with the 93's Secondary AIR setup that doesn't have and EGR port on them. Leave the crank position sensor in the motor as a plug. Use the 93 Throttle Body because the 97 has a different style IAC connector. The water pump, will swap over fine.

The only way he's going to be able to use his opti on teh 97 motor is to swap cams, timing chains, timing covers over to his 93 motor's stuff. More trouble than it's worth, and the 97 vented design is a bit better anyway.

If you guys get stuck let me know and I can probably help further.

[Chris]

From what I understood is that they wanted to swap to obd2 as well

[Fastbird]

From what I understood is that they wanted to swap to obd2 as well

I could see that. What I got from the op was that he simply wants to put the OBD II motor into the 93. If he wants to do the OBDII route then you are exactly right.

[Chris]

It didnt even click to just use the old stuff. I converted thats proly why I saw it that way.

Im sorry if I confused you guys

[Joker Z28]

^Yes Chris he ended up joining after word.

I am tired of hearing all the problems hes running into doing the swap. PITA

Fast bird is there a number we can reach you at if you dont mind talking on the phone? You can PM me if you like.