Motronic, mo' problems

[Snork]

Hey everyone. I've been doing a fairly non-standard project on my car the past week, and already posted on bimmerforums, but they were a bit more interested in shadow lining trim and wide grilles (with some exceptions), so here goes...
My 92 525i has 260k when i bought it this summer. My friend and I rebuilt the engine and suspension (credit goes mostly to him).
Now what we didn't anticipate is that the engine was a replacement with VANOS, but the harness and computer were from a non-vanos engine (presumably the old one). But it worked okay so i left it alone for a while, until I failed my emissions miserably. Now, I am switching the computer and wiring harness and have obviously had some problems. The harness, computer and MAF are from an automatic 95 325is. Now, it had an asc unit, which i've left out, but it also has an extra plug leading into the relay box, which looks like a 5 pin plastic thing. also some ground cables do not reach the mounting points on the shock tower.
Does anyone have experience with this? What should I watch out for? Am I in danger of frying the DME if i don't plug the harness in correctly?
Any help and tips on this wouild be greatly appreciated.

[ArtemLepilov]

In short:

We have a 413 DME from an automatic E36 325 from 1994-5
We have a harness from a 1995 E34 525i with VANOS
We have a 1992 BMW E34 car body w. everything else pretty much and a manual transmission
And we have a motor from a 1993+ BMW E34 525 - which is an M50TU

All of the aforementioned has to work together somehow...

Few problems we ran into:

Crankshaft pos sensor doesnt seem to have a right connector (they are both males, and I worked around it by splicing two female connectors and connecting them together, but I dont know if thats enough or whether I was supposed to be doing that in the first place.)

The harness has an extra plug and wires where the connector plugs into the DME, one of them is an 8-pin connector, and the other is 6 random wires with "pin-connectors"

Basically, we are hoping the thing runs after we put it all together and are trying to sort out all these little differences as to try and minimize the random variables for it not to start.

Thanks yall... Artem

[ArtemLepilov]

Guys, please reply - I have no idea and am lost, The motor in the car was a 1993+ already, so its not our fault that we are trying to do this whole nightmare project. The harness in the car was from the old motor and so was the DME. I wasnt able to tell it until we took the motor apart, so I couldnt prevent the purchase. It was a nice project, and the car has everything else working perfectly. It has 265k miles on it.

[Ferret]

Guys, please reply - I have no idea and am lost, The motor in the car was a 1993+ already, so its not our fault that we are trying to do this whole nightmare project. The harness in the car was from the old motor and so was the DME. I wasnt able to tell it until we took the motor apart, so I couldnt prevent the purchase. It was a nice project, and the car has everything else working perfectly. It has 265k miles on it.

If it's emissions are buggered because the cams are out of time, you might want to rip out the vanos kit completely. You can fit non vanos cams and timing sprockets and they'll fit inside the vanos head without the vanos timing electronics

This way you can lock timing and the emissions should be good - what fault codes are lodged in the ECU?

[ArtemLepilov]

The problem is a bit of both - emissions and wiring. We had an M50 non-vanos motor we could have used instead. All we really have to get working is this stupid wiring.

The thing about the motor is its freshly rebuilt, so we really dont want to tear into it anymore. The ECU has no fault codes, the check engine light isnt on.

Everything is fine except for the emissions and sluggishness of the car.

[Ferret]

The problem is a bit of both - emissions and wiring. We had an M50 non-vanos motor we could have used instead. All we really have to get working is this stupid wiring.

The thing about the motor is its freshly rebuilt, so we really dont want to tear into it anymore. The ECU has no fault codes, the check engine light isnt on.

Everything is fine except for the emissions and sluggishness of the car.

If it's just sluggish I think your cams are probably locked into the defualt high speed setting - there's lots of stories about the later M52 engines doing this when they defualt on their programming. You're going to have to do a complete engine bay rewire at this rate - but it shouldnt be too hard if you find it a decent donor car. The engine wiring looms handily disconnect into easy to manage chunks

[Snork]

Well, we are rewiriing the engine bay, that's why we have the new harness. As to the sluggishness of the car, i can't say, because i have nothing to compare it to, it's no more sluggish than Artem's old 525i. The main thing is the eye-watering exhaust and emissions failure. I'm just worried im going to fry the computer if i wire something improperly. Should the new dme automatically calibrate the timing?