89 325ix starts then dies

[RWD BLOWS]

I am looking through various relays right now trying to find the right ones to purchase. The main relay was pretty simple the replacement is white, 5 prong with the right circuitry inside the relay, however which ones should i buy to replace the 02 heater and the FP relay?

[Kershaw]

Any 4 prong relay with that blade configuration will work.

[RWD BLOWS]

Okay I will verify before placing the order.

[The Dark Side of Will]

Any 4 prong relay with that blade configuration will work.

Not so fast, killer.
I haven't looked at E30's specifically, but BMW sometimes does strange things with relays. The E23 main relay has the NC/NO pins reversed. If you replace it with a standard relay, the DME is powered with the key off and turned off with the key on.

[nando]

yeah, some relays are triggered with a 12v signal, others are triggered with ground.

The green relay will work for both the FP and O2 heater, the white one is the main relay:

http://www.realoem.com/bmw/enUS/showparts?id=1503-USA-10-1990-E30-BMW-325ix&diagId=12_1515

[RWD BLOWS]

After some investigation it seems that the previous owner grounded a terminal on the fuel pump relay so that when you turn the key to the ON position the fuel pump primes. I have disconnected that wire and I get no operation of the fuel pump until I try to crank the engine. The only problem is the car still doesnt start. I'm waiting on new relays to come but I have a feeling that they aren't the problem. I was able to find some spare to test some stuff out and I found a White master relay but the car will not actually stay running. Also the DME makes a buzzing sort of sound when I turn the key to the on position so I'm not sure if that means its turning "on" or not.

[kronus]

the DME is definitely not supposed to buzz. sounds fried.

[RWD BLOWS]

the DME is definitely not supposed to buzz. sounds fried.

Should it make a noise at all?

[kronus]

nope. nothing in it moves.

[RWD BLOWS]

Okay I just double checked and it's definitely making a constant buzzing sound when the ignition is turned on.

[nando]

The PO pobably fried it with those hack job wire repairs..

[RWD BLOWS]

The PO pobably fried it with those hack job wire repairs..

Probably so, I have found so many things that just aren't right. I will order a new DME and update as soon as I can put it in. I am going to disconnect the battery and unplug all the harness connectors and start checking continuity and ground to make sure there isnt a short in the wiring harness which caused the DME to go bad. I would hate to buy another one just to fry it.

[The Dark Side of Will]

It's ironic how often cars work better before people fix them.

[kronus]

it's not unexpected, though. these are somewhat complex cars, and when they're fixed by people who don't approach it with the mindset of making it work the way it's supposed to, they end up putting botches on top of other botches until it's impossible to understand what it was even supposed to do in the first place. my DD e30 is like that, and I'm still finding crazy stuff in it.

props to OP for taking that on - it sounds like you're trying to put it right.

[RWD BLOWS]

I am pretty particular about how and what I do on things. I have an engineering background. These cars especially the ix's are going to be harder and harder to find. I want it to be as clean as it can be.