Started the car this morning after a cold night and it started fine but ran a bit rough like it was not fuelling correctly and seemed to be  misfiring and only running on 3 cylinders. It seemed to get better once it had warmed up a bit but took a while.

The car normally runs fine and is used everyday but was not used yesterday, nor over the whole weekend where it had happened previously.

What happened then was it mas misfiring upon start up and I had no ABS. I took it round the block and then stopped the car where I revved it hard and it then worked fine no problem.

Today, I never had the problem with the brakes but it still seemed poor in performance for a good ten minutes during warm up.

One thing that has happened out of the blue a couple of times now is that when out driving the car the engine began to miss at low revs (between 2 & 4000) and under perform until above 4K then it takes off like a rocket.

Sounds to me like a fuelling issue, anyone have any ideas what could be at fault or suffered similar effects.

My first thought was it could be a problem with the Idle Valve?

air flow meter??

What about the distributor cap/rotor arm and HT leads?

If you keep the car outside and it gets parked when damp and then thecold gets in it can reak havoc with the smooth running.

Alternatively, if the fault with the brakes is in any way connected, I'd check the vacuum line from the plenum to the servo.  There might either be a leak, or the elbow where it connects to the servo may have come adrift.  This would give poor brakes (no servo assist) and run like a dog (loads of air after the afm has measured the charge).

Probably something completely different!  Good luck.

Cheers lads, will give them a check at the weekend if possible. Actually had the same trouble coming home tonight with the rough running again. Was sporattic before but now seems more common that it has happened again am getting concerned now for sure. Basically went to the bank 2 mins along the road ran fine then stopped again2 mins later for fags and red bull and it spluttered all the way up the road again. I did stop to see if it was maybe an ignition fault perhaps with the ECU but no joy spluttered again, Basically when the revs were applied through the gears it spluttered and then took off in between but there was no common fault I could see in the rev range. I tried it in all gears but to no avail still lumpy as hell and running like crap. Am gutted now just went from edinburgh to aberdeen an back last wed and it never missed a beat.

Seems to be getting worse with the cold weather up in sunny scotland. Had a similar rough idling problem last year when I picked up the car but turned out to be the inlet manifold gaskets being loose, anyway swapped them for the EVO III items and all was well (till now !!!)

Agree with sporty as a good place to start. Especially the alternator earth cable where it fastens to brackets under throttle bodies.

And also agree with SFH3L if you have no servo asist - check elbow where vacuum pipe attaches to throttle body.

Could also be airleak at gaskets between throttle bodies and head. (oops, just noticed you have done that)

Unfortunately from your symptoms so far it could be any one of a number of things.

I posted a list of things to consider a couple of weeks ago. I think it frightened Falkster

http://www.bavarian-board.co.uk/forum_posts.asp?TID=39329&PN=1 - http://www.bavarian-board.co.uk/forum_posts.asp?TID=39329&am p;am p;am p;am p;PN=1

If sometimes it is fine and other times it is like a dog (or won't even start) I would think maybe ECU but this is the expensive bit unless you are able to find a dry solder joint and resolder.

Mine started with the occasional misfire and went through to the point where it would not even start before I found the fault with the ECU which, when repaired, was an instant cure.

There are loads of posts on different furums and websites that I used to get test data and procedures to test each component. Have some stored as favourites and just printed others off.

Here is one from close to home

http://www.bavarian-board.co.uk/forum_posts.asp?TID=23333 - http://www.bavarian-board.co.uk/forum_posts.asp?TID=23333

Hope you find it without too much trouble.

Is it present when engine hot and cold or just one or the other.

And here is another (very long) thread from s14.net

http://www.s14.net/forums/showthread.php?t=16467 - Engine cutting out at all temps

Just a word of advice if you get to the point of swapping out ECUs. Make sure your idle control valve is good before doing so as I understand that a bad idle control valve can damage the ECU - particularly the transistors that control the valve and "manage" the idle speed through the warm-up process.

I hope it is something easy. You are sure it is not to do with the onset  of the cold and damp weather

Thanks guys, potentially I think this could be an alternator issue. I did a search on a high pitched whine coming from the engine bay I have experieneced recently as well which could point to the alternator.

The pitch increases in relation to engine speed but this has only happened a few times.

I think the brakes issue was a one off, possibly as a result of the engine not running the alternator corrrectly at the time. If this powers the servo assist then this could definately be the case.

Is their anyway to test the alternator, never tested one before.

To check alternator use appropriately set voltmeter across battery terminals. With engine off volts should be about 12. With engine running, and ignition lights out (maybe rev it a bit to, say, 2000rpm)  a good alternater will give a reading of about 13-14volts.

I guess as well if your battery is not going flat the alternator is working.

Maybe worth getting battery tested if you have any doubts about it.  Go somewhere you trust for this test - easy for people to put a tester on and just say you need a new battery. Top quality replacements are about £80. most give a 3 or 4 year guarantee.