533i Eng harnesses

E28 technical advice asked and given! Troubleshooting, modifications and more.
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Quadrajet
Posts: 14
Joined: Jan 24, 2010 12:31 PM
Location: Oak Harbor, WA

533i Eng harnesses

Post by Quadrajet »

So I am swapping motors in two 533s. The motor from an 83(03/83) going into an 84(08/84) . I checked realoem and as far as I can see it says the harnesses have the same part number from 9/82.
But I noticed the wiring harness from the 84 car has a barometric sensor that mounts to the firewall just above the motor. The 83 wiring harness doesn't have a barometric sensor, that I've been able to locate. Fortunately I have both cars, and I looked on the 83 I cannot find one.
Do I need to swap over the wiring harness?

brownsw44
Posts: 47
Joined: Jan 15, 2015 8:04 PM
Location: Rochester, NY

Re: 533i Eng harnesses

Post by brownsw44 »

I'd say no, unless you think you need the functionality of the sensor where you live.

I've had a number of cars with the wiring for the sensor, but no sensor, and ones with the sensor. I could never discern a difference in driveability.

However, when you make that run up route 20 it might be useful :D

Quadrajet
Posts: 14
Joined: Jan 24, 2010 12:31 PM
Location: Oak Harbor, WA

Re: 533i Eng harnesses

Post by Quadrajet »

Thank you for the reply brownsw44! I take it you've been out this way?
I decided to swap the harnesses, as I have friends in Idaho and eastern WA that I visit every now and again. I'm sure it will read "sea level" 99.92% of the mileage I'll put on it.

ScottKendall
Posts: 43
Joined: Jul 07, 2015 10:01 PM
Location: Kentucky

Re: 533i Eng harnesses

Post by ScottKendall »

I'm going to say something I hope is helpful. The engines are the same and I assume you have the 83 harness and the 84 harness. It also sounds like you have both ECUs, you have both cars??? minus things or complete? So just use the ECU that doesn't need the sensor. Either harness is the same except for the sensor wire that you won't need.

Quadrajet
Posts: 14
Joined: Jan 24, 2010 12:31 PM
Location: Oak Harbor, WA

Re: 533i Eng harnesses

Post by Quadrajet »

I have both, strangely enough both ECUs have the same part number. I've already gone ahead and swapped over the wiring harness. Besides the Baro sensor, the ground point for the FI was in a different spot. Other than that, it was pretty much all the same. What a pain to get that clip off the cold start valve connector!

I took the opportunity to clean all the ground lugs and put a little smear of grease on them. Might as well while access is good.

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