Hi all this question must of been asked and asked.
But i have done an engine swap!!
From a 318i 1990 to a 325i 1985. The pins in the c101 dont mach up ok i can move the pins. But the problem is the fuel pump won't run unless i loop a live to it in the c101 connector. Plus my rev counter is not working. everything in both cars worked perfect before the swap.
There is also a c104 3pin connector by the ecu white,green and blue wire i have to connect the green wire back to the c101 into a live to get the coil to work and the car starts.
But as i have said there must be away to get fuel pump working with out just feeding it a live?
Thanks for any help.
Hotfoot
Engine swap
Moderator: martauto
-
Brianmoooore
- E30 Zone Team Member
- Posts: 49359
- Joined: Mon Jan 10, 2005 11:00 pm
I take it that's a '85 engine (and matching gearbox) into a '90 car.
The best solution would be to ditch the primitive engine management of the '85 2.5 engine, and to replace it with a post '87 six cylinder engine loom and ECU. If the six cylinder was a two litre, then the 'chip' inside the ECU would need to be replaced by a 2.5 one, such as supplied by "Speedtouch' on here. This later loom wouldn't have a C104, and the C101 would plug straight in with all pins correct.
If you do go down this route, it's essential that you check pin 20 of the car side of the C101 and check that there isn't a thin brown wire connected to it. If there is, it should be cut away and insulated.
I think you'll find that the blue wire to the C104 is black, and this needs to connect to pin 9 of the C101, which is the rev. counter wire. The white C104 wire is the 'fuel rate signal' and this goes to the white/black wire on pin 8 of the C101.
Alternatively, the other half of the C104 in the car that the engine came from can be spliced into the wires from the C101 in the loom to the instrument cluster, where they pass above the ECU.
Do you realise that the fuel pump only runs when the engine is turning, not when the ignition is turned on? If the fuel pump doesn't run when the engine is cranked, are you sure that you are getting sparks at the plugs?
The best solution would be to ditch the primitive engine management of the '85 2.5 engine, and to replace it with a post '87 six cylinder engine loom and ECU. If the six cylinder was a two litre, then the 'chip' inside the ECU would need to be replaced by a 2.5 one, such as supplied by "Speedtouch' on here. This later loom wouldn't have a C104, and the C101 would plug straight in with all pins correct.
If you do go down this route, it's essential that you check pin 20 of the car side of the C101 and check that there isn't a thin brown wire connected to it. If there is, it should be cut away and insulated.
I think you'll find that the blue wire to the C104 is black, and this needs to connect to pin 9 of the C101, which is the rev. counter wire. The white C104 wire is the 'fuel rate signal' and this goes to the white/black wire on pin 8 of the C101.
Alternatively, the other half of the C104 in the car that the engine came from can be spliced into the wires from the C101 in the loom to the instrument cluster, where they pass above the ECU.
Do you realise that the fuel pump only runs when the engine is turning, not when the ignition is turned on? If the fuel pump doesn't run when the engine is cranked, are you sure that you are getting sparks at the plugs?