Anyone had a similar issue on Z1 not starting...

[Ian W]

My beloved Z1 has had to spend 9 months outside whilst constructing a new garage. I'd removed the battery to keep it charged up, so fitted this back in, went to start as usual but no joy. She turns over fine but doesn't fire. I've tested fuel pump and spark, both of which seem to be working fine. It's almost as if the immobiliser part of the alarm isn't turning off...? She has a Cobra Thatcham 1 and I managed to track down and plead with a guy that used to fit them to come and check it and he tested all that he could and was 99.9% sure it's not the immobiliser as the whole system seems to be working fine. He suggested replacing the crankshaft sensor (as apparently this was a common problem on the E30) and would cause similar issues. I did this, was full of hope but unfortunately still no joy. The alarm key fob seems to be working fine, it locks and unlocks and the flashing red light goes off as usual when pressed, giving you 30 seconds or so to start her. Sorry, bit of a long tale but just wondered if anyone has suffered something similar and managed to find the solution?
My options currently seem to be towing her to a garage the alarm guy recommended where a really good mechanic works, hoping he can find the problem or biting the bullet and getting the alarm guy to come back and rip out everything connected with the alarm system.... either of which will be very expensive!

[HankLloydRight]

How old is the petrol? Perhaps the fuel has turned if you didn't use a stabilizer?

Good luck, I hope you find the problem.

[Ian W]

Thanks for the response - it's not something I'd considered (I only tend to put Shell super unleaded in) but it's definitely worth a try before more expensive options. Cheers

[HankLloydRight]

I'm not an expert, but if the car lets you crank the motor AND you have spark, I can't imagine how else the alarm system would prevent it from actually starting.

[Robert T]

Have you got fuel to the cylinders? If it's not firing, I'd expect the plugs to be wet.

Cheers R.

Sent from my SM-G991B using Tapatalk

[Stoertie]

Hi Ian,

Have you checked the thick round connector under the intake manifold/throttle valve? The contacts are 30 years old and are oxidising. If these contacts are black, they should be replaced. The crimp contacts (male and female) are available from BMW as a spare part, but it's a really nasty job because you have to extend the cables, otherwise the connector bodies will no longer fit into the holder.

The injection valves are controlled via this connector and also the temperature sensor for the engine control unit runs via this connector. If these contacts are oxidised, this leads to the strangest errors, especially during cold starts.

Regards
Michael

[survivalist]

How have you tested the fuel pump? Mine was making all the right noises but not actually pumping any fuel and was subsequently diagnosed as the reason the car wasn’t starting.

[bluejay]

Have you tried the pressure regulator? Mine was faulty as the vacuum line got porous and wasn,t getting the pressure regulator not activating, which caused the fuel prssure to drop in the line. This caused the engine difficult to start but eventually would run.

RJ

[Ian W]

Thank you everyone that responded, all really useful suggestions. After trying out various options to no avail, I decided to call it a day and have the car transported to my local BMW Independent guy. After 4 hours he finally had success! The taped up loom wiring heading into the battery had eased some of the wires out of the battery terminal connector so to the naked eye all looked connected but the mechanic found power wasn't getting to the ECU. He re-crimped the wires together and all worked fine; so the alarm guy was right, it was nothing to do with the original Cobra alarm! I was so pleased to have her working again....however, this was short-lived as I didn't make it back home from the garage and had to get the poor thing back on a transporter! I shall start a new thread where hopefully you good people can give me some help with the next instalment