Z3 2.8 won't start after extended lay up.- Fixed!

[smiffy]

Hi folks

I'm sure I'd get there in the end, but I'm also sure I can speed the process with your input!

Drove it into my garage, to do a quick re-bush, 4 years ago, and it's now ready to leave, except she won't start!
Battery was disconnected.

Dash lights as normal, cranks over. No spark and no fuel.
Fuel pump runs if I bypass the relay.
OBD system I'm using is Delphi, which has always been excellent connected via 20 pin connector under the bonnet, and is showing no fault codes. ECU has been reset. OBD1, no 16 pin under the dash.

Car is pre-face lift 2.8 with M52B28 single Vanos engine.
Build date May 1998
Spec list does not include factory fitted alarm, so it must have been fitted by the dealer.
Keys are the older non-remote version.
I don't have a brick type remote, the alarm has never been used, but has never caused an issue. Always just locked it on the key.

Should I be looking at an alarm/immobiliser issue caused by the long disconnect period, or does it point towards engine issue?

Thoughts really appreciated, pressures of life means time to work on it is limited.

 

[Ianmc]

Spec list does not include factory fitted alarm, so it must have been fitted by the dealer.

I think all Z3 alarms were dealer fitted. Mine is a fully specked ex demonstrator but the alarm was dealer fitted on arrival in the UK in early 1997.

 

[smiffy]

I guess what I'm really asking, is, does either the alarm or ews system have the capability of shutting down spark and fuel pump, whilst still allowing the engine to crank ove?

 

[GZed]

Engine cranking over but not starting can be sometimes be caused by a faulty MAF.

A quick, free and simple test of this is to disconnect the plug and then try and start it.

If the engine does fire up this would be a good indication the problem is either the MAF itself, or some problem on the air intake side that makes the car think it’s the MAF. With the plug disconnected the engine computer ignores the MAF will and runs on default settings.

Wisdom on here then says to do a smoke test to look for leaks before instantly jumping to conclusions and buying an expensive new MAF. And also to put a code reader on it.

 

[ktnez99]

Hi folks

I'm sure I'd get there in the end, but I'm also sure I can speed the process with your input!

Drove it into my garage, to do a quick re-bush, 4 years ago, and it's now ready to leave, except she won't start!
Battery was disconnected.

Dash lights as normal, cranks over. No spark and no fuel.
Fuel pump runs if I bypass the relay.
OBD system I'm using is Delphi, which has always been excellent connected via 20 pin connector under the bonnet, and is showing no fault codes. ECU has been reset. OBD1, no 16 pin under the dash.

Car is pre-face lift 2.8 with M52B28 single Vanos engine.
Build date May 1998
Spec list does not include factory fitted alarm, so it must have been fitted by the dealer.
Keys are the older non-remote version.
I don't have a brick type remote, the alarm has never been used, but has never caused an issue. Always just locked it on the key.

Should I be looking at an alarm/immobiliser issue caused by the long disconnect period, or does it point towards engine issue?

Thoughts really appreciated, pressures of life means time to work on it is limited.

My Z is a 2.8L and the factory fitted immobiliser was, as you’ve guessed, fitted as BMW built the car.
Could this be an issue with the immobiliser because the car has been parked up for so long with the battery disconnected?

 

[Pingu]

How do you know there is no spark?

Why did you need to bypass the fuel pump relay? Are you saying that the fuel pump relay is kapput?

Confirm it has fuel in it.

If you can get underneath and jack the car up, disconnect the fuel pipe on the engine side of the fuel filter and confirm the fuel pump is able to pump fuel through the filter.

Confirm that the fuel is ok. I did this by putting some in another car (mine was laid up for three years).

 

[smiffy]

right, update on this, and answers to suggestions, (all appreciated).

@GZed - MAF data is visible on Delphi and can see it reading when cranked. Tried with it disconnected, no different.

@ktnez99 - I've ruled out the EWS immobliser as that also isolated the starter motor. As it turns over, it can't be the immobiliser. I think that also rules out the alarm.

@Pingu - initially identified "no spark" by pulling a plug out, pushing the plug into the coil with a jump lead clip, with the other end grounded and cranking. Old school, look at the plug. since done more which I'll explain in further detail.

It still won't start!

No P Codes showing, but we clearly have comms with the car as various sensors are feeding back to the diagnostics.

Immobiliser - ruled out as that directly isolates the starter motor operation, independent of the DME, so if it was an immobiliser issue, it wouldn't crank.

Fuel pump - is working correctly. It primes the system to around 40psi initially, then increases fuel pressure to around 45psi during cranking. Pressure gauge installed in the fuel line directly after the fuel filter. Fuel filter has been replaced.

MAF - via the Delphi system, shows a default reading of 40KGH before cranking, rising to 8000KGH after a starting attempt. Suggests the MAF is working. Also makes no difference disconnected.

Throttle sensor - is reading via Delphi, and varies when moved.

DME Relay and what it feeds - DME is alive so relay must be working, we also have 12v supply present at both ignition coils and injector wiring.

Crankshaft Sensor - first test was voltmeter in DME connector 5v supply good. Then in signal connector, turned engine by hand and watched the voltage step. Then connected storage 'scope to same point and cranked engine. Clean 5v squarewave including the odd TDC marker. It's not that.

Camshaft sensor - shouldn't affect starting, but tried with and without. Tests with multimeter in line with suggested impedances.

Vanos coil - measures 23ohms which is about what I'd expect, also makes no difference disconnected.

Sparks - Here's where it starts to go wrong. - when I connect the scope to the DME connector, Ign 1 (pin 29) I would expect to see 12vdc, until it is cranked, when I would expect a negative pulse grounding the primary coil. It just drops to 0V continuously whilst cranking. Same applied to Ign 2 (pin 1). No spark, confirmed visually as mentioned at the top of this.

I need to go back and check the injector pulses, which I think may be the same.

But it seems loss of Ignition signals is a know fault as it is mentioned here https://www.actronics.co.uk/ecu/siemens-ms41/1429861 but it doesn't explain why it's not throwing any fault codes. Maybe it's to do with it being a MS41.0 series DME?

Any ideas folks?

Next step is probably send the DME for testing.

 

[IanA]

What is happening to the battery voltage while all this is going on? We've seen a lot of weird problems on the forum that were solved using a new battery.

 

[smiffy]

What is happening to the battery voltage while all this is going on? We've seen a lot of weird problems on the forum that were solved using a new battery.

Brand new battery, that also has maintenance charger. Cranking speed is fine, so no drop at starter. I might just check the supply at the DME during cranking though.

 

[IanA]

The 200A fused supply from the battery feeds the busbars underneath the fuse box. Access by dropping the glove box. If the voltage is low there, the engine won't even crank. There are six 80A feeds from the busbars to the various relays. A low/no voltage from one of them might inhibit functions that affect others?

 

[smiffy]

Finally back to trying to resolve this, but now armed with INPA.

Also, DME has been away for EWS delete, and I've sourced a second DME, also with EWS deleted.

Having read the BMW_EWS document found in another thread here, it seems that bit is all working fine.

Still no firing, but cranking fine as before.

INPA is showing what I think is the issue, on both DME's.

In ENGINE > STATUS > DIGITAL STATES 1.

I have Input Anti Theft System > ON.

On my original DME, it is flicking between On and Off. On the spare, it is solid On.

Having never looked at a car with INPA, I don't know what states stuff should indicate, is this wrong? Is this linked to the Alarm rather than the EWS?

 

[smiffy]

Well, I finally got this running!

In desperation I reached out on an e36 Facebook group, and a chap in New Zealand responded!

Ended up buying the software to download, check, and modify the code in the DME's. Downloaded the files out of both DME's, emailed them to NZ, where my new pal checked them. Both had EWS delete enabled, but also contained errors in the code, which gave an end result of the same issue, everything working but no spark or injector pulses.

A new "bin" file was created and emailed back to me, which I then uploaded into one of the DME's. Considering it hasn't run for 4 years and I've been messing about with it all summer, she fired up within a second of cranking, which caught me a bit off guard as the garage door was shut! Honestly expected all sorts of errors or something disconnected!

So, what caused it? Well, the comms between EWS and DME modules wasn't sync-ing even though the codes in both units matched. That is the root cause and the "anti-theft" marker shown in INPA sort of confirmed that.

Why it took so long to resolve, is down to the poor service of the company selected to firstly EWS Delete my own DME, which contained errors, and then they supplied a DME "ready to go", when I suspected a physical fault, but that also contained the same coding error!

I've not raised the issue with them yet, but I suspect the answer will be, "you've tampered with it", or "you should have contacted us first", so not expecting anything useful from them now.

This is who I used, but I certainly DO NOT recommend them. https://digital-tuning.co.uk

It's not £250 I spent with then, it's the time consumed sorting their repeated errors that's most annoying.

Just got to put it all back together now!

Oh, if anyone has a similar problem, I have a spare MS41.0 DME with EWS delete, you can borrow for testing!