UK Z3 2.0 1999

[ShaneHull]

I'm dealing with a non-start on an E46 currently.

I would look for the easy to fix stuff first and/or that you would need to do anyway. So I would:

• check the fuel pump fuses
• change the fuel pump relay, preferably just swap it with another light green relay known to work like the horn
• change the fuel filter which could be clogged
• pull the DME out and check there is no corrosion. Disconnect the battery first. Sounds nasty but it's not
• check all the earth points in the engine bay are secure.

My non-start is probably a crankshaft sensor so I agree with Lee but it may not be a 2 minute job to change and should in theory be throwing an error (the E46 is).

If you are handy with a voltmeter then seeing what you can find on the relay base can be revealing. This will tell you if you are getting a ground from the DME to fire the pump. If not then the crankshaft sensor is a serious culprit or possibly the DME relay. You can also jumper the supply/load sockets to see if you can run the pump directly (listen out for it, it's directly behind the driver's seat underneath the carpet.

This is the electrical stuff you need to know. I drew it up for the E46 but I can't see why it wouldn't be the same for the Z3. Socket 8 gets a positive when you turn the key to the Run position before the Starting posn on the ignition. Socket 4 gets a ground from the DME and keeps it after firing. You'd jumper 6 and 2 to run the pump directly, preferably with a fused jumper. No ground means the DME is not releasing the fuel pump to run. Deliberately due to (probably) the crankshaft sensor or non-deliberately due to wiring fault.

View attachment 68389

Thanks for the advice.
I've checked out the fuses - all's ok
I'll have a look at the relay this afternoon
I've bought a new fuel filter - need to find out where the old one is located
Where is the DME
Earth points look fine, but to make sure I'll disconnect, apply contact grease, reconnect and test.

Does anyone know where I can get a copy of the "BMW Z3 1996-2002 Bentley Service Repair Manual" from? As I'm not sure where the fuel filter and DME are located

 

[andyglym]

Thanks for the advice.
I've checked out the fuses - all's ok
I'll have a look at the relay this afternoon
I've bought a new fuel filter - need to find out where the old one is located
Where is the DME
Earth points look fine, but to make sure I'll disconnect, apply contact grease, reconnect and test.

Does anyone know where I can get a copy of the "BMW Z3 1996-2002 Bentley Service Repair Manual" from? As I'm not sure where the fuel filter and DME are located

Try this link from Pelican Parts, may be of help?

http://www.pelicanparts.com/BMW/tec...placement/25-FUEL-Fuel_Filter_Replacement.htm

 

[mrscalex]

Thanks for the advice.
I've checked out the fuses - all's ok
I'll have a look at the relay this afternoon
I've bought a new fuel filter - need to find out where the old one is located
Where is the DME
Earth points look fine, but to make sure I'll disconnect, apply contact grease, reconnect and test.

Does anyone know where I can get a copy of the "BMW Z3 1996-2002 Bentley Service Repair Manual" from? As I'm not sure where the fuel filter and DME are located

The DME is located at the left rear of the engine bay as you look in. In a box with a plastic lid on. There are about 6 screws holding the lid on.

When you get in you'll see 4 or 5 connectors going into a silver box - that's the DME. You need to disconnect each of these. The big ones have a lever catch you need to disengage and I think there are a couple of simple pull off ones. You may need to lift the DME up to remove some of the connectors - I can't recall off the top of my head. You must disconnect the battery though. This is the central brains of your car but don't be intimidated. Just be careful removing the connectors and don't drop it!

You are looking for signs of corrosion. It's not uncommon and can be fatal if it's on a critical pin. I've seen cylinder 4 firing pin corroded, it stopped sending the signal to that coil and the engine got upset and blew the con rod/bearing through the sump! So it's good routine preventative maintenance anyway. Probability this is your problem? Minimal but it's an easy 10 minute check.

The fuel filter on UK models is on the left side (facing forward) about half way down under an aluminium cover. It's cylindrical and about 10 inches long. That will do no harm at all to routinely change.

Bentley from Amazon or ebay. But expect to pay $100+ with shipping. But it's a great investment.

 

[mrscalex]

Btw. Certainly reasonable to put your model in the title. But put your issue in their too and it might get you a wider audience. It looks a bit like it might be a for sale advert currently

 

[mrscalex]

Try this link from Pelican Parts, may be of help?

http://www.pelicanparts.com/BMW/tec...placement/25-FUEL-Fuel_Filter_Replacement.htm

Pelican is generally very good. I'm surprised it doesn't get more mentions on here.

Re-reading that reminds me of something else. Check the vacuum line that runs into the engine. Virtually every Z3 I've seen the rubber is perished where it comes up from the chassis rail onto the engine. Probably not your non-starting issue though. And also check all other vacuum/rubber pipework in the engine bay has it does go over time. But more likely to cause poor running than no running.

 

[Shelly]

Hi and welcome from me too

 

[ShaneHull]

Just had a thought, could it be the car immobilizer, stopping it from starting.....
And does anyone know how to check and if necessary re activate the key?

 

[mrscalex]

In short yes it could be. But you’re better off ruling out the easier stuff first.

There are 2 points of failure I am aware of.

1. The key is not recognised. There is a radio antenna collar round the lock barrel to talk to the key and they can pack in. Or the battery in the key may be flat. But if either was the case I don’t think the car would turnover.

2. The EWS has got it’s knickers in a twist and is out of sync with the DME. But I would expect to see corresponding error messages - key mismatch. I believe it can be resynced from within INPA. But getting up and running with that on a laptop can be a trial.

On an E46 where my lockout experience comes from diagnosing and resyncing both points are nice and easy by a piece of software called BMW Scanner. But it doesn’t work with E36s to the best of my knowledge.

Note I think the EWS is a chassis error not an engine error. To the best of my knowledge the cheap readers can only read engine codes even when plugged into the engine bay port. I tried it the other day. On that basis you would need INPA on a laptop plugged into the engine port to diagnose an EWS error.

So we’re back to where we came in. Rule out the simple stuff first.

Whereabouts are you? Perhaps there’s a forum member nearby who can help with INPA when you’re ready.

In the meantime we really need to see what engine codes you have from a cheap scanner.

 

[Ryan]

Welcome. Hope you get the car sorted. It’s a good car to find the issues for. Easier to diagnose, that age of car