NB: TURNS OFF WHILE DRIVING!

[93_Clubman]

Given you're going to look at the ignition circuit, if you haven't already, it might be worth checking the wiring to the coilpack as on the NB8A it deteriorates where it deflects just prior to plugging into the coilpack. Apparently the combination of deflecting & not being well supported in this particular spot, probably compounded by alternating high & low temperatures, weakens the wires. It's not immediately apparent to the eye, but if you move this part of the wiring loom around while the motor is running you'll get a response in terms of idle if there's a problem.

Btw, tks for posting the cause of Caff's EGI relay issue.

[luzinit]

Thanks for the tip 93_Clubman, spent some time on the car today and checked the 3 ground points in the engine bay with a multimeter and also checked coilpack wires as you suggested.

Couldn't find a faulty with any of these areas.

The remaining ground I didn't check was the one on PPF. Will need to get the car on jack stands to do this.

Whilst checking the car out I noticed some coolant leaking from hoses near rear of engine, so will need to get this replaced ASAP.

I'm hoping its the ground on the PPF otherwise I am pretty stumped!

[93_Clubman]

Power cut out and luckily there were no cars around me and I managed to pull into a shoulder lane.
This was the third EGI relay to fail on me and luckily I had a spare.
I noticed that the relay was quite hot, is this normal?
It sounds like I have electrical gremlins in the car after going through a few relays now I, what should I be checking for?
I've also noticed that my battery tends to run flat if the car is not started during the week.

Got the car going, blew a fuse and EGI relay, whilst troubleshooting I found some really dodgy alarm installation wiring that will need to be sorted out. I'm talking exposed wiring and wires soldered directly to relay pins.

With the EGI relay cover off, I could see that the issue is that the coils aren't generating a strong enough magnetic field to close the switch/arm on the relay. Read up on it and shorting the coils inside the relay can do this.

I PMed caffeine and his issues with his relay was due to a dodgy light bulb connector (I believe he had bulbs constantly blowing in addition to the relay woes). After he fixed this, his issues haven't reappeared.

So your NB8A is repeatedly burning out EGI relays like Caffs (& Caffs appeared due to a faulty light globe connector). The car has also blown a fuse on at least one of these EGI relay burn outs, & the battery tends to go flat if you don't start the car during the week.

Which fuse/s have blown, & since finding the dodgy alarm install (& tidying it up or removing it I assume) have you also been blowing fuses & flattening the battery as previously mentioned?

While it would be nice to identify exactly why it's happening in your car, Manga's suggested solution from p2 might be worth a shot:

I took most of the load off the OEM relay by installing a pair of 30A relays to the 12V side of the coilpacks. They draw power through 50A wires direct from the alternator white wire post and only use the original output from the OEM relay to trigger them. It means that the OEM relay now stays cool and it's lasted for years. I had blown a couple of them previously and they showed signs of overheating in their coils and had serious pitting on their points.

[luzinit]

Which fuse/s have blown, & since finding the dodgy alarm install (& tidying it up or removing it I assume) have you also been blowing fuses & flattening the battery as previously mentioned?

While it would be nice to identify exactly why it's happening in your car, Manga's suggested solution from p2 might be worth a shot:

I took most of the load off the OEM relay by installing a pair of 30A relays to the 12V side of the coilpacks. They draw power through 50A wires direct from the alternator white wire post and only use the original output from the OEM relay to trigger them. It means that the OEM relay now stays cool and it's lasted for years. I had blown a couple of them previously and they showed signs of overheating in their coils and had serious pitting on their points.

The blown fuse was my own fault as I connected the wrong pins to hardwire the relay, ended up blowing the 15A Engine fuse, so wasn't a symptom, more so a result of something stupid I'd done in an attempt to quickly start the car whilst broken down and holding up traffic!

Had a closer look at the alarm wiring and although it looked really dodgy on first inspection, it wasn't too bad up close. Some wires needed to be insulated which I did.

After replacing the 4 year old Supercharge MF43 battery, I haven't had it drain any longer so I suspect it was just an old battery on it's way out. Also did a parasitic draw test and couldn't find any shorts with any of the circuits relating to any fuses inside the car.

I'm determined to find this problem! If I can't find it soon then might have to go and do what manga_blue did...

Thanks a lot for the suggestions and feedback!

[93_Clubman]

Assuming the PPF earth is ok & you feel the alarm installation isn't a contributing issue, then it would be worth checking the ECU.

Re ECU, I'd mainly be looking for water damage, which on a few NB8Bs has caused elusive issues. Obviously disconnect the battery if you unplug or remove the ECU - if you open it up check the PCB for any scortching or burning, or even discolouration around capacitors (more a 4AGE 20V ECU thing).

As you know from researching NB8A issues there are a few, some of which have been elusive - Patty's comes to mind: viewtopic.php?f=29&t=47266

[luzinit]

You're the man! I almost forgot to check the ECU and it was certainly something I thought I had to check as I'm sure I came across some mention of it during my research on this and other forums for this particular issue.

I will report back, hopefully get to the bottom of this so that other owners will find this useful at some point in the future.