Need Help Finding Computer For 1991 M50 Motor!!!

[beck74]

I am looking for a computer for a M50 motor. I switched out my bad M52 out of my 94 and replaced with a 91 M50. So now I need a computer for the M50 motor. When I started the car with the M52 computer some wires started smoking. Does anyone know where I can buy a main computer for a 1991 M50 motor?

[smcgowan]

What's the bosch number on the side of the unit?

example below...

[Jon K]

Gonna be a 403 I think

[Kai@e34.de]

yes, should be 403 or 405. and btw., your '94 engine is a M50TU, not M52.

hope you also have switched the engine wiring loom, air mass sensor and so on?

[MarkD]

You can use a 405, 403 or 402. The 402 was the last version and then the M50tu used the 413. Why did you even try to run that motor with a 413 ECU? It's completely different, it has VANOS and knock sensors which the earlier M50 does not have.

As Kai mentioned, you need to change the harness also. It would have been much simpler to drop in another m50tu or even an m52.

MarkD

[winfred]

a vanos brain and harness running a non vanos motor should not automaticly smoke, properly hooked up theres a chance it may even run ok (with a obvious vanos solenoid code, unless he swapped in the cams and mounted the servo) i am guessing something wasn't hooked up right under the intake, had a car come a couple years ago that a boat mechanic?! had installed a motor in for the guy that he bought from us that had popped 4 computers one after the other (douchbag ya think he would of learned) turns out he had some sensors crossed up and the computer was back feeding itself and frying various things, computers among them

[beck74]

Thats the problem. I do not have the old ECU from the M50 motor. I just have the M52 ECU. Do you know how I can find out what number I need for the M50.

[beck74]

what do u mean 403 or 405? Do you mean I have to replace the entire wiring harness?

[beck74]

What do you mean 403? Is this number on the ECU itself?

[beck74]

You can use a 405, 403 or 402. The 402 was the last version and then the M50tu used the 413. Why did you even try to run that motor with a 413 ECU? It's completely different, it has VANOS and knock sensors which the earlier M50 does not have.

As Kai mentioned, you need to change the harness also. It would have been much simpler to drop in another m50tu or even an m52.

MarkD

I did not know it would be this difficult. What do you mean by the numbers? Does this mean all the wires have to be replaced? Even the ones that go to the lights and so on?