m50b25 vanos fuel but no spark

[drakesmith]

As dan said and I have before. .

You have wired up a earth that should be a earth to be a live. Ecu earth is my bet. On the m52 loom side of it.

There is diagrams on the wiki on here for the plug setups.

Do they correspond to your wiring?

Have you wired it up for a diagnosis to work? Fault codes?

[Eeken98]

But now i have the grounds and positive connections right on the engine harness so it has to be something with the body to engine wires or have both ecu died
I dont have a diagnostic plug on the harness
The problem why it came 12 volt out of ground points was because of wrong connected wire frome engine to body harness

[Brianmoooore]

the wires that comes out of the body on the e30 are not the same as any wiring diagram

This is because you are using the E30 C101 body loom wire colours, while most connection diagrams/tables refer the the colours of the old E30 engine loom to the C101 plug.
All the diagrams refer to the fuel pump wire as green/purple, which it is in the engine loom, but on the E30 body loom, it's purple/red between the C101 socket and fuse 11, before reverting back to green/purple for the rest of the run to the pump.

If the brown and/or brown/orange earth wires from the engine loom are connected to earth/battery negative, the plain reds are connected to battery positive and the main engine to body earth strap is in place, then all you need to get the engine to run is to apply ignition switched 12 volts from pin 13 to the green in the engine loom, which turns on the ECU and feeds the ignition coils, 12 volts starter signal from pin 18 to the black/yellow in the engine loom for the starter motor solenoid, and to feed the fuel pump supply from the green/purple in the engine loom to pin 13, so that the fuel pump runs when instructed to do so by the ECU.
It's that simple. All other wires in the C101 are for instrumentation or minor details.

[Eeken98]

the wires that comes out of the body on the e30 are not the same as any wiring diagram

This is because you are using the E30 C101 body loom wire colours, while most connection diagrams/tables refer the the colours of the old E30 engine loom to the C101 plug.
All the diagrams refer to the fuel pump wire as green/purple, which it is in the engine loom, but on the E30 body loom, it's purple/red between the C101 socket and fuse 11, before reverting back to green/purple for the rest of the run to the pump.

If the brown and/or brown/orange earth wires from the engine loom are connected to earth/battery negative, the plain reds are connected to battery positive and the main engine to body earth strap is in place, then all you need to get the engine to run is to apply ignition switched 12 volts from pin 13 to the green in the engine loom, which turns on the ECU and feeds the ignition coils, 12 volts starter signal from pin 18 to the black/yellow in the engine loom for the starter motor solenoid, and to feed the fuel pump supply from the green/purple in the engine loom to pin 13, so that the fuel pump runs when instructed to do so by the ECU.
It's that simple. All other wires in the C101 are for instrumentation or minor details.

so you mean that its two wires that has to be connected to pin 13 in the body connector?

[Brianmoooore]

My notes (from a M50Tu into an E30 conversion that I did about thirteen years ago) state that a medium plain green wire and a thin plain green wire from the M50 loom both need to be connected to pin 13 of the E30 C101.

[DanThe]

Two green to Pin 7 which is Ignition to coils and ECU
Pin 13 is fuel pump feed which is Green/Purple on your engine loom and Purple/Red on the fusebox side

[Brianmoooore]

Oooops! I'm not really helping when I post basic mistakes like that. I think the loss of 10,000 brain cells a day is finally beginning to take effect.
Dan is right, of course, as are my notes. Pin 7 is the ignition feed, with two green wires in the M50 engine loom, and 13 is the pump feed.

[DanThe]

Make sure you dont connect the EWS signal wire which is also a thin green to Pin 7

[Eeken98]

But now i have another problem i only got 1 thick green wire all the other are 2 colored wires

[Eeken98]

But now i have another problem i only got 1 thick green wire all the other are 2 colored wires

[DanThe]

[Eeken98]

is it me being stupid now or?

[pianist]

Now i have removed the all wires that goes to the transmission plugg and joined all the wires that goes to the ecu plug from transmission plug to 12volt and nothing did change

Is this the right thing to do? I mean did you know these all wires have to be connected to 12v+ or did you just guess? I'm only asking cause this is a sure way to fry your ecu just by connecting random wires to live or ground and see what will happen.

[Eeken98]

Now i have removed the all wires that goes to the transmission plugg and joined all the wires that goes to the ecu plug from transmission plug to 12volt and nothing did change

Is this the right thing to do? I mean did you know these all wires have to be connected to 12v+ or did you just guess? I'm only asking cause this is a sure way to fry your ecu just by connecting random wires to live or ground and see what will happen.

I did only join the wire that i have read i should join so

[Eeken98]

do anybody know if the second wire that needs to go to pin 7 can be a diffrent color?

[Eeken98]

Dont anybody know?

[Brianmoooore]

It won't be a different colour. The colours of wires in the looms aren't random, but are chosen according to a code. Ignition switched, unfused wires are plain green.
The M50 looms I've had experience with have had two separate green wires to the plug, but designs change, and BMW probably use looms made by more than one manufacturer, so your loom may have an internal splice joining the wires somewhere.
All that matters is that the wire connects to pin 3 of each ignition coil plug and pin 56 of the ECU plug. Use a meter to check for continuity between the green wire and each of these pins.

[Eeken98]

Okey now i have spark and fuel finally but the the battery die so when its re charged it mayby starts

[Speedtouch]

Good luck, fingers crossed for you!

[Cyant1fical]

Hope this works for you, this is one of the plans for me when I do my engine swap, how did you find it?

[Eeken98]

i disconnected all wires that was going from engine harness to body harness and only wired pin 18, 13 and 7 so it had to be a wrong wire that messed all up that was wired to the body harness

[Eeken98]

i didnt get it to start so i started look for problems i have looked at the timing it is a little bit off but it runned like that before so i also did a compression test on all 6 cylinders and it was not good on 1. cylinder i got 9bar little low but i did go on 2-4 was good and then 5 was only 5 bar and 6 didnt even move the compression tester so i think its the piston rings or could it be the valve gaskets? I have changed the head gasket before i lifted it in to the e30. but it comes oil in the cylinders so i think its piston rings then this project is not going so well

[drakesmith]

Thats not gd. I have never heard of a M50/M52 to jump the timing. These engines are quite good at not jumping.

You sure you haven't bent valves ??

[Eeken98]

Thats not gd. I have never heard of a M50/M52 to jump the timing. These engines are quite good at not jumping.

You sure you haven't bent valves ??

I need to check it but i think its best to pull the engine not many bolts to undo to pull it out just my luck that every think is fu### up when i try something

[Speedtouch]

Hehe, we've all been there when attempting major modifications such as engine swaps.

I'm sure you'll get there eventually...

[drakesmith]

Thats not gd. I have never heard of a M50/M52 to jump the timing. These engines are quite good at not jumping.

You sure you haven't bent valves ??

I need to check it but i think its best to pull the engine not many bolts to undo to pull it out just my luck that every think is fu### up when i try something

You have checked it. No compression normally is a sign of bent valves 100%

[Eeken98]

Thats not gd. I have never heard of a M50/M52 to jump the timing. These engines are quite good at not jumping.

You sure you haven't bent valves ??

I need to check it but i think its best to pull the engine not many bolts to undo to pull it out just my luck that every think is fu### up when i try something

You have checked it. No compression normally is a sign of bent valves 100%

So the valves can be bad in the other cylinder to were its bad compression? And is it that problem that makes oil come in the cylinders?

[Eeken98]

Thats not gd. I have never heard of a M50/M52 to jump the timing. These engines are quite good at not jumping.

You sure you haven't bent valves ??

I need to check it but i think its best to pull the engine not many bolts to undo to pull it out just my luck that every think is fu### up when i try something

You have checked it. No compression normally is a sign of bent valves 100%

So the valves can be bad in the other cylinder to were its bad compression? And is it that problem that makes oil come in the cylinders?

[Speedtouch]

That would normally be down to either a failed head gasket or extremely worn valve guides.

[Eeken98]

That would normally be down to either a failed head gasket or extremely worn valve guides.

Okey i have new head gasket so. But im gonna have to pull the head and look at the valves but how do i make the timing right its a little bit of the cams should be 45° to at tdc but they are not that. Do you know what to do?

[Speedtouch]

I've only ever worked on one twin cam head, which was a Renault Clio RS 182, but you ideally need to use a tool (either bought or made) to lock the cams at the correct position prior to fitting the timing chain/belt and torqueing up the head.

[Eeken98]

I've only ever worked on one twin cam head, which was a Renault Clio RS 182, but you ideally need to use a tool (either bought or made) to lock the cams at the correct position prior to fitting the timing chain/belt and torqueing up the head.

Yes i have that tool

[Eeken98]

Now the head is off an the valves on the cylinders that had bad compression is leaking alot but how do i fix? does it help to just buy new valves or?

[Speedtouch]

If you suspect the valve stems are bent (thus causing lack of seal in the valve seat, and low compression), then they will have to be replaced.

Find out what caused them to bend in the first place!

If they aren't bent, then remove them and replace the valve guides and/or valve stem seals (if fitted), then grind them into the seats with valve grinding paste and suction stick.

Ensure valve guides are spotlessly clean and oiled prior to refitting the valves.

[Eeken98]

If you suspect the valve stems are bent (thus causing lack of seal in the valve seat, and low compression), then they will have to be replaced.

Find out what caused them to bend in the first place!

If they aren't bent, then remove them and replace the valve guides and/or valve stem seals (if fitted), then grind them into the seats with valve grinding paste and suction stick.

Ensure valve guides are spotlessly clean and oiled prior to refitting the valves.

no valves was bent. But do i need to replace the valve guides or can i just grind them down?