318Ti to 325Ti convertion

[mooseheadm5]

Use a bently manual or BMW wiring diagram and check that the DME has all the powers and grounds that it needs. campair indicated that this is where his problem was, but the dealer did not tell him exactly what. Start there (make sure you use the DME pinout for the 325 not the 318) and report back.
-Paul

[campaiar]

I looked at my service bill and it indicates that the DME and EWS units were not receiving + & - power on the correct pins. I'd start there.

Have you checked for spark and fuel pressue? I had neither when I first tried to start mine.

[andrei]

Originally Posted by campaiar

I looked at my service bill and it indicates that the DME and EWS units were not receiving + & - power on the correct pins. I'd start there.

Have you checked for spark and fuel pressue? I had neither when I first tried to start mine.

I don't have any spark or fuel. I am going tommorow morning to my local bmw dealer to sort things out since I don't have proper OBD I bmw testing equipment.

[mooseheadm5]

OBD1 testing equipment may not help. Like I said, see if you can figure out the wiring by comparing the wiring diagrams for your car vs the donor car. Pay aprticular attention to the X20 connector (round plug for the engine harness) and see if any of the connections there are not right. BMW is very good about keeping the wiring colors the same for all cars, even when they move the pins around in the connector (like crank signal is black/yellow.) They may have even intentionally done this to prevent what you are doing right now. Before you give up and take it to the dealer, try peeling back the boots on both sides of the X20 connector (next to the fuse box) and seeing if there are any wires that don't match, or match from one side to the next but are in different locations. Good luck.
-Paul

[andrei]

In this picture it seems there are two wires from the engine wireing harness that go to + and only one for ground. This is one mistake I made because I only put the + one the largest red cable and the rest on ground. So it seems that tommorow morning I will try to connect these the right way and like mooseheadm5 said try to look at the x20 connector.

One more thing: From what you guys say even if I have OBD I and EWS1 I still don't need to reallign those at the bmw dealer? Is it enaugh if the wireing harness is made to be compatible with the cars harness?

[mooseheadm5]

You should not need EWS allignment. If the donor ECU does not have EWS and your ti does, then all you have to do to keep the EWS from talking to the computer is cut the wire that the EWS output is on. I was told by Turner Motorsport that it was pin7 on the X20, but looking at the wiring diagram, it says EWS to the DME is on pin 20 and is a 0.5mm black wire. Maybe they were wrong (!) Try looking at that too. i did not have that issue because I removed EWS from my car entirely (you can try this by temporarily unplugging the EWS module and joining the large green/black wire with the black/yellow wire with a jumper, this will give you cranking signal without EWS.)

[Rich]

http://www.318ti.org/forum/showpost....1&postcount=27
here is an X20 connector comparison I made for my car when it came to checking the engine loom/car loom connection. My car was running OBD II for both the original M43B16 and the M52B28. This was a simple swap over of the ESW to the donor engine units and replacing the chip in the key to the donor chip. As mentioned before Pin7 in X20 connector is the signal from the ESW unit to the ECU. This sends a coded signal to the ECU, if the signal is not received the start/fuel pump will not run.

So long as you have everything switched over from the donor there should be no need to have any calibration done.

[andrei]

But the donor car is a 1991 one and has no EWS. My car is 1994 and I think it has EWS I. Is there anything besides the engine harness and DME that I can use from the donor car to start the engine?

[andrei]

If I swap part 3 from here with part 3 from here shouldn't my car start?

[mooseheadm5]

No. That is the transmitter module that the antenna ring plugs into. The EWS controller is what can make the car not start. However, if the DME does not have EWS, and you remove the EWS controller and join those two wires I talked about so you get crank signal, the EWS can definitely not prevent the car from starting. That is part 1 on the diagram and if you have it, it is behind the glove box. It is the box at the bottom in the center and is marked EWS. Check both cars, but I think EWS was introduced in 94 in Europe, so the 325 should not have it.
The pictures I took didn't come out too well, but take a look. The two bundles of wires with the red bands are power and the smaller one is ground in the picture you show. Mine shows one solid red wire, and you can;t see the end, but the other wire bundle has a red band on it. The last wire is bolted to the car below the diagnostic connector. It is all black and is a ground wire. I mentioned something about pin 20 on the X20 connector being related to EWS. It is, but it is only a tach signal to the EWS controller and does not matter. Pin 7 is the important wire related to EWS. If you donor DME does not have EWS (which I am 99.999% sure about) and you cut the green wire to pin 7, then you have taken EWS out of the picture for your no start problem. Your problem must then be in the wiring to the DME for power or ground, as all the engine control signals go through the harness, which is matched to the computer.

[andrei]

There are 3 wires that need to be connected to either +(hot) or -(ground). I have connected the big red wire to +(hot) and the other 2 to ground because they were black. I did not have a wire with a red label on it. It seems that I have the same wiring as you have except that my second wire is not labeled with any red band.
Should I try to connect this one to power (+)? I am a bit scared as I don't know what could happen if I was wrong and my wiring was different from yours and mine hase two ground wires and one power.
I will post a picture with these wires.

[andrei]

By the way mooseheadm5 what year is the engine you used? Is it VANOS or NON-VANOS? I think you mentioned sommewhere in your thread that it was a 1995 but I just whant to be clear on this. I think that nonVANOS engines like mine have a little bit different wiring that VANOS engines so that is why I might think that mine doesn't have the second power wire. I think I need to see a picture from campairs engine bay and see how he hase his wiring because his engine is a non VANOS 1992 like mine is.

[mooseheadm5]

Yes, my engine is 95 with Vanos. If you peel back the cover of the wires you can tell which is ground and which is power because all B+ constant power wires are red and all ground wires are brown. As far as I can tell, the X20 connector has the same pinout for Vanos and non-Vanos. Hope that helps.

[andrei]

I going tommorow to try to connect that second wire to +. Hope everything goes well.

[mooseheadm5]

Here is a tip when you do that. Disconnect the computer first, then connect the wires. That way, you can turn on the car and check the ECU plug for proper power and ground and you won't have to worry about hurting anything.

THIS IS FROM A US SPEC 92 325i, closest I can get, should be identical:

Constant power from junction block B+ (My battery is still up front, so my power comes straight from there.) Pin 26 - this same connection powers the ECM relay which in turn powers the injectors, terminal 86 on the fuel pump relay and terminals 86 and 30 on the O2 sensor relay. It also powers PIN 54 on the ECU. The ECU grounds the ECM relay. If you have no power to these my guess is that this is the connection that is missing. Supposedly, there is a second splice that powers terminal 30 at the fuel pump relay, so check to see if you have power at terminal 30 of the fuel pump relay at all times (key on or off.)

Gound at pins 6 and 34.

Switched ignition power at pin 56 (only has power when you turn on the key.)

I think your issue is that there are two power wires for the harness. I think one goes from the battery to the starter/alternator/fuse box and the other bundle does all of the engine power. The third ground wire bundle does all ECU grounds. It is a little confusing, as the lug at the end of the second bundle of + wires and the ground wires is the same size and can easily be bolted to the same spot or even switched, as was probably the case with campair's car.

-Paul

Do you know how to read the BMW wiring diagrams? If you do, I have US spec diagrams I can send you from a 92 325i and a 95 318ti in .pdf format if you think it will help. Pm me your email address.