no spark?

[ZombiE30]

I did that too!
"holy shit, everything is broken! oh....wrong table"

Anyway, did everything else check out ok?
Have you checked for fuel?

If you have fuel pressure and the injectors are opening and closing (listen for clicking individually with a stethoscope) and everything else is good, I may recommend finding some way to heat the ECU to about 90 degrees and seeing if it starts then.
That will test if it's bad/worn out transistors causing your no-spark issue.

[!kid]

i still have yet to check for fuel i will do this on the weekend when i have day light to work in. i get off work during the week just as the sun go's down. also my battery went to shit i get 12.4 volts but it wont turn the engine over. i grabbed the battery from my sisters car and it turns over fine but still no spark.

its only about 56F at night when i am trying to start it do you really think that heating it could help ? i guess ill give it a try tomarrow

[ZombiE30]

ONLY 56??

Anyway, yes it is a possibility, though I assumed you were in a location with actual weather.
Mine wont start under 32. It's possible your wont start under a balmy 58.

In any case, yes, check the fuel.

Also, when your car doesn't turn over, turn on all the headlights and every damn thing. Then try to start it and see what happens. If the headlights dim, then you've got a bad connection/short/problem on the main load side of the circuit. If the headlights stay bright but the engine wont turn, then you've got a problem on the control circuit (smaller one that tells the starter when to engage).

[!kid]

iam sure the battery is no bueno. its 3 years old and ive over charged it twice with in the last week. iam going to have it tested if i can find the time.

[!kid]

i took the fuel line off the back of the pressure regulator and set it in a bottle then cranked the motor ....no fuel came out ... there is about a little over two gallons in the tank and the fuel light is not on. also i put a hair dryer to the ECU got it nice and warm still no spark.

[!kid]

ok so i put power to the fuel pump and i got fuel to come out iam starting to think my ECU has died on me.

[!kid]

rust ...on the inside of the ECU is that bad hahahah ill post a pic ASAP

[!kid]

[!kid]

so i went to my local junk yard and got another ECU. took it out of a 1989 325i auto trans. i have a 87 325i that had an auto trans.


i still do not have fuel or spark

my 87 ECU 0 261 200 153 CA1E

89 325i ECU 0 261 200 525 also has sticker CA5E

is there any reason the ECU would not work for my car ?
can i use an ECU from any car with a M20b25 ?

[handysmurf59]

have you tested the pulse sensor resistance? Having a similar problem with my 87 325iC. No spark, but cranks fine.

[!kid]

yeah i have and it was with in spec

[!kid]

my rusty ECU on the left and the one i got from the pick a part on the right
dont belive i got the correct one they are way different or am i wrong should it work?

[jlevie]

The 525 DME will work fine. You have some other problem. No spark or fuel pump operation says that:

The DME isn't getting timing data from the engine (bad CPS)
The DME isn't getting power (bad main relay or fusible link)
The DME is bad

Since a different DME had no affect, the last possibility can be ignored. That leaves DME power or the CPS as the culprits. I've posted it before, but below is a trouble shooting guide that should help.

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 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 & 47, 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.

[!kid]

2) Check the resistance across DME 47 & 47, 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.



is this a typo ?

i think you ment 48 and 47

[!kid]

so i just did all the checks and two of them came out no good

with key on i have no voltage at DME pin 27

and key on i have ground at DME pin 2,14,19,24