E30 Zone

Just had the AA out,drove home and reversed back into drive way and the engine cut out.The guy diagnosed that there’s no spark and the fuel pump only runs when it’s linked directly to the battery.Any ideas please.

Just spoke to my macanic,there’s voltage coming out the coil but still no spark,also the air gap on the CPS is too wide.he’s also checking all the readings coming out of the ECU from a BMW technical website.

Crank sensor. Check wiring by water pump pulley.

Just changed it,exactly the same

Check for 12 volts at the + terminal of the coil with the ignition on by connecting a 12 volt lamp between the terminal and a good body earth (top of RH suspension turret.) Check that it stays lit when the engine is cranked.
Turn the ignition on, and pull out the DME relay (white one under the cover near the air filter). Does it click as you pull it out, and click again when you push it back in?

The relay is clicking in and out,I couldn’t do the lamp test.

That confirms that the ignition switch is at least working in position 2, and that the ignition signal is reaching the ECU, and at least turning part of it on. It also confirms that no conventionally installed immobiliser is causing the problem.
Any missing voltage at the coil, would only affect the sparks and not the fuel pump.
We had a similar case recently, where the problem eventually turned out to be with an aftermarket CPS. This was replaced by a second one of the same make, and the engine still wouldn't run until a genuine one was fitted., so what CPS have you fitted?

It’s one I’ve had hanging around for a while,I can’t remember where I got it from.can I test the one I took off.

You can measure the resistance between two of the terminals, which should be around 540 ohms (IIRC). Open circuit indicates a duff sensor, but a correct resistance reading unfortunately doesn't confirm a good one. A few shorted turns will damp the output, but not show on a resistance check.
We never did get to the bottom of exactly what the problem was with the aftermarket sensors. The sensor is only a coil of fine wire wound around a magnet, and the output signal is by no means critical.

I’ve just tested the one I took of the car tonight and between pin 1 and 2 600 oms

Seems a bit high for a genuine sensor, but as I've said in my post above, you can prove it's dud, but not prove it's good.
Try replacing the DME relay with two wire links, connecting 30 and both 87s of the socket together, and try to start the car. This will check out the DME relay.
Don't leave the links in place after the test.

Hi Brian,many thanks for your help to start with, quick update I’ve just tried the obove linking out the relay exactly the same,just cranks over.so if this isn’t getting confusing I’ve now tried 2 cps and 2 relays and checked fuse 11 with a volt meter and it reads fine,unless I’ve got all nacked stuff,other than that any other ideas.

There isn't a lot left except the ECU itself. Extremely rare for them to fail, but not impossible.

Brianmoooore wrote: ↑

Wed Feb 03, 2021 9:31 pm

That confirms that the ignition switch is at least working in position 2, and that the ignition signal is reaching the ECU, and at least turning part of it on. It also confirms that no conventionally installed immobiliser is causing the problem.
Any missing voltage at the coil, would only affect the sparks and not the fuel pump.
We had a similar case recently, where the problem eventually turned out to be with an aftermarket CPS. This was replaced by a second one of the same make, and the engine still wouldn't run until a genuine one was fitted., so what CPS have you fitted?

It was me that had the issue with 2 aftermarket CPS and my 325 not starting. Fitted an new OEM one from BMW and she started 1st turn of the key. My recommendation is if you are fitting a CPS go OEM. Might cost more but could save you a whole load of hassle.

Brian: I emailed Meat and Doria about the 2 sensors that didn't work but I never got a reply.

Ok I’ll keep you all informed.

I also experienced the same issue with aftermarket CPS units - go OEM.

Paul

The one that was on the car last night is the Oem as it left the factory.the other is another oem but from a scrap yard a few years back.From all the post your sending,I’m wondering if the original one has packed up and the scrap yard one many never worked,but I do remember it being on the car and working.

Have you tested spark and fuel yourself whilst cranking it? Is the starter motor turning?

Have you checked the pump is actually delivering, I get that and a whack with a hammer gets it going and starting. (Must bite the bullet and get a new one, soon as my poxy pension allows).

Just spoke to the mechanic doing my car, he said there’s fuel from the pump getting to the fuel rail without linking the fuel pump to battery and there’s a spark from the coil but not at the distributor.The plot thickens.

There's no possible common cause between the two things you mention so it's likely that one might be the actual fault, and the other a fault caused by the attempts to find the fault.
There's only a length of copper wire with a resistor in it between the coil and distributor, or does he mean no spark at the plugs? That could be a disintegrated carbon button inside the distributor (or a broken cam belt!)

Thanks for the reply Brian,I’m not sure if he meant the plugs or the distributor,but I don’t think it’s the dizzy cap because it was brand new about 6 months ago and the cam belt was done in October.

When fault finding, the first thing I look at is anything that has been replaced recently. The failure rate of things follows the 'bathtub' curve, plus there's the possibility of the part not having been fitted correctly.

I see where your coming from,hopefully ill have some more news in next few days.

When I had the problems with my 325 not starting I had the following symptoms:

With a spark plug connected to the king post of the coil when I turned the key to position 2 I would give a single spark.

When all connected back up and trying to start the car the fuel pump would run but no spark at the plugs. Turned out to be the CPS.

The Meat & Doria CPS gave a signal to allow the ECU to run the fuel pump but not create a spark.

New OEM CPS and bingo. First turn of the key she started.

Does above sound like what you have?

I had a cut out yesterday, again. floored it away and boom! cut out, clobbered the fuel pump with wheel brace and off we go ever since.

MunsterScot wrote: ↑

Thu Feb 11, 2021 7:48 pm

When I had the problems with my 325 not starting I had the following symptoms:

With a spark plug connected to the king post of the coil when I turned the key to position 2 I would give a single spark.

When all connected back up and trying to start the car the fuel pump would run but no spark at the plugs. Turned out to be the CPS.

The Meat & Doria CPS gave a signal to allow the ECU to run the fuel pump but not create a spark.

New OEM CPS and bingo. First turn of the key she started.

Does above sound like what you have?

Cheers mate, this sounds like the fault,I’ll pass the info onto my mechanic.

ah wrote: ↑

Fri Feb 12, 2021 4:15 pm

MunsterScot wrote: ↑

Thu Feb 11, 2021 7:48 pm

When I had the problems with my 325 not starting I had the following symptoms:

With a spark plug connected to the king post of the coil when I turned the key to position 2 I would give a single spark.

When all connected back up and trying to start the car the fuel pump would run but no spark at the plugs. Turned out to be the CPS.

The Meat & Doria CPS gave a signal to allow the ECU to run the fuel pump but not create a spark.

New OEM CPS and bingo. First turn of the key she started.

Does above sound like what you have?

Cheers mate, this sounds like the fault,I’ll pass the info onto my mechanic.

I doubt it. You said you had sparks at the coil. A single spark would be expected when you turn the ignition on, so any mechanic worthy of the title wouldn't consider this to be sparks in the normal sense.

Sounds like dizzy or rotor from what you explained above about spark at coil. Or a dud HT lead from coil to dizzy

Just for the record, what OEM brand(s) do you guys use?

I do believe Bosch is OEM for all electronics on E30 (give or take some VDO here or there) but is Hella also OEM?

For OEM CPS I went to BMW dealer. The part didn't have a manufacturer name on it.

HJ1981 wrote: ↑

Sun Feb 14, 2021 9:50 am

Just for the record, what OEM brand(s) do you guys use?

I do believe Bosch is OEM for all electronics on E30 (give or take some VDO here or there) but is Hella also OEM?

'Hella-Behr' is now a cheapo low quality brand, ive sent back several radiators and wont use them anymore

If it is just Hella or Behr then it should be quality but I doubt it is

MunsterScot wrote: ↑

Sun Feb 14, 2021 12:03 pm

For OEM CPS I went to BMW dealer. The part didn't have a manufacturer name on it.

It is an expensive €170 from the dealership.

DanThe wrote: ↑

Sun Feb 14, 2021 8:26 pm

HJ1981 wrote: ↑

Sun Feb 14, 2021 9:50 am

Just for the record, what OEM brand(s) do you guys use?

I do believe Bosch is OEM for all electronics on E30 (give or take some VDO here or there) but is Hella also OEM?

'Hella-Behr' is now a cheapo low quality brand, ive sent back several radiators and wont use them anymore

If it is just Hella or Behr then it should be quality but I doubt it is

Thank you, i found a Bremi brand one, think it is good? the rest are Meyle, Magneti Marelli, Facet etc.

Out of those choices Bremi would be the one id buy

Update at top of page

Have you tried a spark plug connected to the lead from the king pin of the coil? Connect a spark plug to the distributor end of the lead from the king pin of the coil and lay the spark plug on the rocker cover. Try and start the car and see if you get a spark. If yes, then the issue is with the distributor / arm. If no, then the ECU is not triggering the timing circuit for the coil to create a spark. This is based on you have
12V on the green wire to the coil when the key is turned to position 2.

When mine was like that it was the CPS. As mentioned above I tried 2 new Meat & Doria CPS and they didn't work. I had to get an OEM one from BMW.

The thread I had on my issue is here: viewtopic.php?f=2&t=281331

Might be worth a ready to give you some ideas.