ECU/ DME for a M30 Swap - interesting info

[revitoff10]

Hello,

I have a 87 325is that has a cracked head (200k miles on it). I just got an m30 engine, trans, driveshaft, and ECU out of a 90 535i. I do not have the enigine harness out of the 535i, the guy just cut the heck out of it to get the enigine out quick. Anyways, in my quest to figure out whether I can use the m20 harness and just plug the 535i ecu in, here is what I found. I thought this my help others.

I ran the BMW Vin Decoder on the 535i vin that is also on the ECU. I used this website http://www.bmw-z1.com/VIN/VINdecode-e.cgi Came back as a 90, manual, m30. Per the e30.de website it is a 1.3 motronic from an 89-92 535i or 735i

The ECU in my 87 325is - per the E30.de website, my bosch part # 0 261 200 179 is a 1.3 motronic for an 87-91 325i. The vin number on the ECU does not match the vin on the car. The previous owner had put a dinan chip in the car (not sure if you send in you ECU or not). Not sure if this had anything to do with the vin on the ECU not matching the car. BUT, the car ran for a year + for me, and who knows how long with the previous owner with the ECU in the car. Plus according to the e30.de website and others this is an ECU part number for a 325i. BUT, here is the interesting thing - when I run the vin decoder on the vin # on the ECU - it came back as a 12/86 build date for an E28 manual 535i.

Anyways, I thought this may help explain why some people have sucessfully used the 325i ecu to run their m30 engine. We will not complete the swap for a couple of more months, so I can't say for sure that either/both ECUs will run the car, but I'm guessing it will.

Hope this helps someone,

Veronica

[E30SPDFRK]

Interesting stuff, I'm looking forward to seeing if it works. e28's were a earlier version of motronic, right?

Also, welcome to the forum! It's nice to see girls working on cars as well.

[Jb325is]

That is interesting because e28 m30's never had the 179 ecu. Crazy stuff!

[euroshark]

I'm pretty sure the decoder is incorrect. M30 powered E28s never came with Motronic 1.3. 1.3 gets it's reference signal from a toothed wheel on the front of the engine whereas 1.0 and 1.1 get the signal from the flywheel. Injectors, temp sensors and AFMs are different between the two as well, therefore an M30 E28 with the Motronic 1.1 harness could not even start on a 179 ECU, let alone run. The only E28s that had 1.3 are the late 528e "super eta", and that might have run the 179 ECU, but that still doesn't explain why the decoder thinks it's from an '86 535i.

The reason M30 swapped E30 guys have been able to use that ECU is because the later E30s ran Motronic 1.3 as standard.

A

[revitoff10]

Well,

The decoder may be wrong. It's certainly possible. For the most part is seems to be ok - I've checked it for a couple of cars and the decoder seemd right. The last 7 on the vin on the ecu is 1716242. The sticker has certainly been on the ECU for awhile, it's got that aged, slightly dirty look and does not seem likes it's been tampered with. Anyways, the ecu bosch # is a 1.3 for a 325i, so who knows. But if it works I'll have an extra ECU from a manual car for an M30 that someone might be able to use. Does anyone know how to decode the first part of a BMW vin? I can't seem to find anything with all the codes for some of the earlier sections.

The car has certainly has things replaced over the years. We just took the drive shaft out and it's definately not the original. Has a remanufactured sticker on it and is marked for a 635 - but who knows. It is a two piece, but it has a spline with a collar that screws on to keep it in place on the back section of the two piece. There is no nut by the u joints in the center to undo. Putting in a new center line bushing would be simple on it. The drive shaft from the 535i and on my E39 have the impossible nut to get off in between the u joints in the center of the two pieces. I don't know why someone would need to replace the drive shaft, but the car has a lot of things done to it. Makes me wonder, but the frame is straight and that's all I need right now.

[JoeMadoo]

1.3 gets it's reference signal from a toothed wheel on the front of the engine whereas 1.0 and 1.1 get the signal from the flywheel.

Pretty sure M1.1 and 1.3 are interchangeable. I ran motronic 1.1 on my m30 for a while until i found a 1.3, but they both use the front sensor.

I would recomend using an e32/e34 harnesss just for simplicity and aestetics.

[revitoff10]

I hear ya, but don't have one at the moment. We'll see what I can find cheap before I get to that point. I won't be at the stage until March/April at the rate I'm going.

[itsbrokeagain]

Im starting to look into M30 swaps..good deal for the money.


Hard part is finding a good 535 or E32 lying around...cant find one that isnt M50 or an auto...lol

[SpecM]

I'm pretty sure the decoder is incorrect. M30 powered E28s never came with Motronic 1.3. 1.3 gets it's reference signal from a toothed wheel on the front of the engine whereas 1.0 and 1.1 get the signal from the flywheel. Injectors, temp sensors and AFMs are different between the two as well, therefore an M30 E28 with the Motronic 1.1 harness could not even start on a 179 ECU, let alone run. The only E28s that had 1.3 are the late 528e "super eta", and that might have run the 179 ECU, but that still doesn't explain why the decoder thinks it's from an '86 535i.

eh... I hate to dissagee with you, but Motronic 1.1 is very much like 1.3, minus the advanced self-diag. Motronic 1.0 gets its reference from the flywheel, 1.1 gets it like 1.3 does. And super-etas had Motronic 1.1.

[euroshark]

Interesting... I must have my Motronic versions mixed up then. What in the world is the version that uses the standard 059 ECU and flywheel sensor? I have always seen that referred to as 1.1 since 1.0 should be the much older system used in early etas, early euro 3.4s, and the 533/633/733.

The 059 ECU reads off of the flywheel sensors and to my knowledge that's the best / latest ECU used in the M30 powered E28s. They may have had a sensor on the front of the engine but it was only used for diagnostics. E24s on the other hand got the later electronics without the flywheel sensors in the middle of 1987...

[Spinning Tires]

It seemed to me that the easiest way was to use the stock e30 harness (provided you have an 87-91) just extend the injector harness. That way it hooks up to the car easily. You may have to extend the MAF meter wire too but im not sure i didn get that far yet. Then use a motor and computer from an e32 or e34. my donar was an e28 so i had to buy and oil pan, oil pump, computer, and i still need a balancer with the refrence marks on it. also i believe the e34 and e32 have an oil filter housing with oil cooler ports on it.

[duodvlhntr]

Motronic 1.1 and 1.3 are similar. 1.0 is the one that runs off the flywheel. 1.1 and 1.3 run off the toothed wheel at the front of the engine. However, you are right euroshark when you say that the 1.0 had a sensor in the fron that is used only for diagnostic purposes. Also, the 87 has the correct wiring harness for the M30. Plug it in and go! Virtually, anyway. Lengthen a couple wires and you should be fine. Unless all the info I've ever gotten from this place is wrong...