quick 2.7i wiring question

[squidmaster]

TL;DNR: Forgot to swap over to the toothed pulley.

got it to crank and turn over, however I suppose I'm not getting fuel.

87e with 88 or 89i top end, full harness, and ecu. I had an entire engine to delve into so I don't believe I'm missing anything.

I get fuel, crank; everything but spark.

[squidmaster]

no spark apparently.

[squidmaster]

bwn, bwn/org are ground for ignition system, right?

[jlevie]

For the engine to run the following conditions must be met:

Power on DME pins:
27 Start Input
18 Un-switched Power input
37 Power Input from Main Relay

Ground on DME pins 2, 14, 19, 24

Timing data from the CPS on DME pins 47 & 48 from a rotating engine

To have spark power must be present at the coil positive and ground pulses
from the DME's pin 1 must reach the coil negative. Power to the coil is
controlled by the ignition switch via C101. When checking for spark, use the
output lead from the coil to eliminate the distributor, rotor and plug wires.

To have injector firing power must be present at each injector and ground
pulses from the DME's pin 16 (Bank1) and pin 17 (Bank2) must reach the
respective injector bank. Note that the injectors are wired as two banks of
three. With cylinder 1,3,5 being bank 1 and 2,4,6 being bank 2. Power to the
injectors is controlled by the main relay. Injector firing is best checked
with a noid light.

The fuel pump relay must have power on pin 86 (relay coil) from the main relay
output (pin 87) and power on pin 30. The DME will ground pin 85 to turn on the
relay and power the pump(s) via pin 87. Of the above, only the fuel pump power
is fused. So if the there's power at pin 87, but not at the pump, check fuse
11.

The main relay and DME pin 18 receive power from the smaller of the two wires
that connect to the battery's positive terminal. That wire incorporates an
in-line fuse. When the DME is presented with a start signal, it grounds the
main relay pin 85 and furnishes power to the fuel pump relay, injectors, and
DME.

Troubleshooting:

Disconnect the battery and the DME cable. Then:

1) Disconnect the coil negative and check continuity from that connector to
DME pin 1. Also verify that from DME pin 1 to ground is an open circuit.

2) Check the resistance across DME 47 & 48, which should be 500-560 ohms. If
the CPS is dismounted, the resistance can be seen to change from about 500 to
540-560 ohms when a ferrous object is brought to the face of the
sensor. Neither pin should be grounded.

3) Check for continuity from DME 36 to main relay 85 and from DME 3 to fuel
pump relay 85.

Reconnect the coil, remount the CPS (air gap should be 1mm), plug the
relays back in, reconnect the DME, and connect the battery. Then do the
following checks:

1) With the key off, verify that power is present at DME pin 18 and main relay
86 & 30.

2) With the key on, verify that power is present at DME pin 27 and pin
18. Power to pin 18 is from the main relay and there should be power to the
injectors and fuel pump relay.

3) With the key on, verify that no voltage is present at the DME grounds (2,
14, 19, 24).

4) Verify that power is present at the coil positive and at fuel pump relay
pin 30. Those get switched power from the ignition switch via C101.

The engine will start and run (if poorly) with only those connections to the
DME in place. The other signals from Cylinder ID, AFM, temp sensor, etc., are
necessary for proper operation. But they won't prevent the engine from firing.

IMPORTANT:

A power check means seeing a voltage within about a tenth of a volt of what
you measure across the battery terminals, which should be at least 12.6v on a
charged battery.

A continuity check means seeing less that 1 ohm of resistance.

An open circuit means seeing a resistance of at least 100k ohms.

A good quality auto-ranging digital multimeter will make these tests much
easier.

[e30trooper]

the two browns are grounds, the red wire goes on the positive terminal on the side firewall.
If you need any help , pmme. I finished my full motronic 1.3 swap on a 86 325e few weeks back

[squidmaster]

I only have an old, shitty VM but it stopped working today. can't even get it to read power directly from the battery terminal (even though the car has power)

windows work
everything works but just lacks spark.

How I tested for spark (maybe I'm also doing this wrong):
Pull one plug, add spare spark plug, ground spark plug, and try to turn it over. I don't get any spark that way.

So, I'm stuck here, alone, with no way to test voltage, and a car that won't run (no way to get new tools). I'm fucked, right? Just give up and don't go to work tomorrow, right?

[ForcedFirebird]

the two browns are grounds, the red wire goes on the positive terminal on the side firewall.
If you need any help , pmme. I finished my full motronic 1.3 swap on a 86 325e few weeks back

Correct.

I only have an old, shitty VM but it stopped working today. can't even get it to read power directly from the battery terminal (even though the car has power)

windows work
everything works but just lacks spark.

How I tested for spark (maybe I'm also doing this wrong):
Pull one plug, add spare spark plug, ground spark plug, and try to turn it over. I don't get any spark that way.

So, I'm stuck here, alone, with no way to test voltage, and a car that won't run (no way to get new tools). I'm fucked, right? Just give up and don't go to work tomorrow, right?

Make sure you don't have the cylinder identification and crank position sensors mixed up on the harness. They have identical plugs and snap into the round diagnostic connector bracket at the front of the intake manifold.

This and having the fuel lines reversed are the most common no-start issues with this swap.

[ForcedFirebird]

For the engine to run the following conditions must be met:

Power on DME pins:
27 Start Input
18 Un-switched Power input
37 Power Input from Main Relay

Ground on DME pins 2, 14, 19, 24

Timing data from the CPS on DME pins 47 & 48 from a rotating engine

To have spark power must be present at the coil positive and ground pulses
from the DME's pin 1 must reach the coil negative. Power to the coil is
controlled by the ignition switch via C101. When checking for spark, use the
output lead from the coil to eliminate the distributor, rotor and plug wires.

To have injector firing power must be present at each injector and ground
pulses from the DME's pin 16 (Bank1) and pin 17 (Bank2) must reach the
respective injector bank. Note that the injectors are wired as two banks of
three. With cylinder 1,3,5 being bank 1 and 2,4,6 being bank 2. Power to the
injectors is controlled by the main relay. Injector firing is best checked
with a noid light.

The fuel pump relay must have power on pin 86 (relay coil) from the main relay
output (pin 87) and power on pin 30. The DME will ground pin 85 to turn on the
relay and power the pump(s) via pin 87. Of the above, only the fuel pump power
is fused. So if the there's power at pin 87, but not at the pump, check fuse
11.

The main relay and DME pin 18 receive power from the smaller of the two wires
that connect to the battery's positive terminal. That wire incorporates an
in-line fuse. When the DME is presented with a start signal, it grounds the
main relay pin 85 and furnishes power to the fuel pump relay, injectors, and
DME.

Troubleshooting:

Disconnect the battery and the DME cable. Then:

1) Disconnect the coil negative and check continuity from that connector to
DME pin 1. Also verify that from DME pin 1 to ground is an open circuit.

2) Check the resistance across DME 47 & 48, which should be 500-560 ohms. If
the CPS is dismounted, the resistance can be seen to change from about 500 to
540-560 ohms when a ferrous object is brought to the face of the
sensor. Neither pin should be grounded.

3) Check for continuity from DME 36 to main relay 85 and from DME 3 to fuel
pump relay 85.

Reconnect the coil, remount the CPS (air gap should be 1mm), plug the
relays back in, reconnect the DME, and connect the battery. Then do the
following checks:

1) With the key off, verify that power is present at DME pin 18 and main relay
86 & 30.

2) With the key on, verify that power is present at DME pin 27 and pin
18. Power to pin 18 is from the main relay and there should be power to the
injectors and fuel pump relay.

3) With the key on, verify that no voltage is present at the DME grounds (2,
14, 19, 24).

4) Verify that power is present at the coil positive and at fuel pump relay
pin 30. Those get switched power from the ignition switch via C101.

The engine will start and run (if poorly) with only those connections to the
DME in place. The other signals from Cylinder ID, AFM, temp sensor, etc., are
necessary for proper operation. But they won't prevent the engine from firing.

IMPORTANT:

A power check means seeing a voltage within about a tenth of a volt of what
you measure across the battery terminals, which should be at least 12.6v on a
charged battery.

A continuity check means seeing less that 1 ohm of resistance.

An open circuit means seeing a resistance of at least 100k ohms.

A good quality auto-ranging digital multimeter will make these tests much
easier.

Jim, I have used this method often, ever since you told it to me in the post.

Quick question, though, do you have this memorized, or do you copy/paste it? lol.

You always have good advice!

[squidmaster]

I have no connections coming off the round diag at all. there aren't even any sockets.
I get fuel, just no spark.

any pictures of what you're talking about?

[squidmaster]

I know, his advice was great, and work would brilliantly... if only I had a VM

[ForcedFirebird]

Follow the crank position sensor on the front of your crank to where it connects to the harness. Then follow the sensor on the #6 spark plug wire to where it connects to the harness. Both of these plugs are identical and are often switched causing a no-spark situation.

[squidmaster]

I tested the coil to make sure, and it works. I also threw another cps and distributor on to make sure, and still same issue. No spark.
Fuel is pumping fine. Just no spark.

What even.

The donor engine was taken out of a car the day I picked it up, and I saw it running (just fine) before it was taken out. So I'm really at a loss here.

[ForcedFirebird]

http://www.strictlyeta.net/technical/328i_6.html

[ForcedFirebird]

Follow the crank position sensor on the front of your crank to where it connects to the harness. Then follow the sensor on the #6 spark plug wire to where it connects to the harness. Both of these plugs are identical and are often switched causing a no-spark situation.

I tested the coil to make sure, and it works. I also threw another cps and distributor on to make sure, and still same issue. No spark.
Fuel is pumping fine. Just no spark.

What even.

The donor engine was taken out of a car the day I picked it up, and I saw it running (just fine) before it was taken out. So I'm really at a loss here.

If the CPS is plugged in the wrong part of the harness, it will not fire!


Go check these two plugs. It actually is very quick to just switch them and try firing it up. If it doesn't fire, you have another issue.

[squidmaster]

Hold up, I took some pictures.