No spark, coil has power.

[Wardie]

ECU had a software issue. Had it Looked at. Works.

[Wardie]

Having the ECU looked at today. I ran through this list and everything checked out just fine:
Note: The readings about the Ohms on CPS has to be false. I've checked two running M20s and they had about 1,200-1,400 readings on them.


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.

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 to 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 540-540 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 0.040"), 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 batter 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.

[e30^2]

Tooth logger looks fine.
I don't know how to check for spark in megasquirt, whodwho looked at a log and said it was being sent.
I didn't wire it up and I dont know where the drivers are.
Wire to coil checks out.

Losing my mind, it almost seems like a grounding issue. I have both of them in the battery tray in the engine OEM spot for Early models.

Im running out of ideas.

Log file: http://www.filedropper.com/2014-11-15191919

Any update? Were you able to figure out the problem?

[Wardie]

Tooth logger looks fine.
I don't know how to check for spark in megasquirt, whodwho looked at a log and said it was being sent.
I didn't wire it up and I dont know where the drivers are.
Wire to coil checks out.

Losing my mind, it almost seems like a grounding issue. I have both of them in the battery tray in the engine OEM spot for Early models.

Im running out of ideas.

Log file: http://www.filedropper.com/2014-11-15191919

[Wardie]

Thing is I didn't even know megasquirt had that. Nor do I know how to get to it. No need to get aggressive my friend. A simple hey you know you can do this by doing that?

[Jaxx_]

After I check the CPS I'm going to open up the board and check connections as it seems to be the last possible thing I haven't checked.

I just don't understand replacing parts when you have megasquirt able to tell you if it is working or not... It's seriously a RS232 port and a few clicks away. But if you want to get your hands dirty and potentially do work for nothing, go ahead I suppose.

[Wardie]

It's a three post cps in the front of the engine. It's a 2.7l stoker so I have the toothed wheel and 325i sensor. It should be reading 500-550. If it doesn't work I can return it. Doesn't hurt seeing that it's likely the cause at least in my understanding.

After I check the CPS I'm going to open up the board and check connections as it seems to be the last possible thing I haven't checked.

I will run though that list tonight. I greatly appreciate it my man.

[Jaxx_]

Seems like the coil is fine and the CPs. Need to test if the dist cap is sending the voltage to the spark plugs.

WHAT? lol pls stop.

Its CPS. Ohm readings is almost 2x amount out of tolerance. I will know tomorrow, getting a new one.

It registers sending signals out.

It doesn't make sense that you are getting timing("sending signals out") but yet the CPS is bad. Replacing a working CPS won't fix your problem. By the way, if it is a 2 wire CPS, it will read differently depending on the metal that is in front of it... hence the reason for a toothed wheel on the engine.

If you are watching megasquirt on your laptop and it says that it is firing the coil, then you need to inspect the coil drivers of the megasquirt board and the route out to the coil. It is clearly an issue there if the coil has power but isn't sparking.

Why don't you inspect the tooth log for megasquirt and make sure you actually are getting timing... then you can move on from there.

Let's go over your check list:

Check timing via tooth logger
Confirm megasquirt software is registering spark in software
Confirm coil drivers are grounding
Confirm coil drivers are attached to wire harness
Confirm wire harness goes to coil

You'll find your issue somewhere in those 5.

[e30^2]

Its CPS. Ohm readings is almost 2x amount out of tolerance. I will know tomorrow, getting a new one.

Are you running MS on an E engine or did you swap the engine?

[Wardie]

Its CPS. Ohm readings is almost 2x amount out of tolerance. I will know tomorrow, getting a new one.

[DesertBMW]

What about it? It registers sending signals out. Alot of wiring has changed in the car so could be anything.

That is why I said it is Megasquirt for you, it is custom system, could be coil driver, dwell time, pull up resistors. It all depends how you build it up. It is hard for us to just speculate on it.

[e30^2]

Seems like the coil is fine and the CPs. Need to test if the dist cap is sending the voltage to the spark plugs.

[Wardie]

Yes, I tested spark at plugs, wires, and coil. Nothing.

Its either the CPS or ECU.

[e30^2]

So, did a few tests with a multimeter.
Power on coil to Strut = 12v
Ground to strut = 12 v
Ground to strut while cranking = constant 12v
Continuity from coil ground to pin 1 ecu is about .879 or so.

So if I am understanding the tests the ecu isn't putting out any sort of ground to the coil when firing.

Sooo yeah? Am I right? Thoughts?

Edit: Running around the ECU pins, Ohm readings on 47&48 are about 867 And when I swap the crank and spark plugs at the front I get 1,050+

CPS is brand new, maybe got a shit one?

Did you test for spark at the spark plug?

[Wardie]

So, did a few tests with a multimeter.
Power on coil to Strut = 12v
Ground to strut = 12 v
Ground to strut while cranking = constant 12v
Continuity from coil ground to pin 1 ecu is about .879 or so.

So if I am understanding the tests the ecu isn't putting out any sort of ground to the coil when firing.

Sooo yeah? Am I right? Thoughts?

Edit: Running around the ECU pins, Ohm readings on 47&48 are about 867 And when I swap the crank and spark plugs at the front I get 1,050+

CPS is brand new, maybe got a shit one?