alpina b10 biturbo electrical/ignition fault - The Unofficial BMW M5 Messageboard (m5board.com)

DAVID NEWTON · 11th December 2000, 14:22

Just in case anybody is still out there, have just found the problem, which has turned out to be the inlet manifold butterfly/accelerator control unit. The car is running very well. Anyhow thanks for all suggestions.
Brgds
David

i bought a 92 100,000 km b10 biturbo, have sometimes a misfire/slight drop in revs on either tickover or actual running. i have changed the dîstributor cap, ht leads etc, plugs are good and the correct type, plus the colour seems okay, rotor arm okay, lambda sensor okay and i have also now installed the correct air filter. before i brought the car out to switzerland from england i had it checked out for the same thing, the garage couldnt find anything. anybody any ideas please, thanks david

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DN

[This message has been edited by DAVID NEWTON (edited 12 December 2000).]

[This message has been edited by DAVID NEWTON (edited 15 March 2001).]

CarlT · 12th December 2000, 19:49

Hi David

I guess the DME has no fault codes? I had a simular problem on a different model, and it turned out to be the crankshaft sensor giving erratic signals to the DME. Just a thought..

Regards
Carl

DAVID NEWTON · 13th December 2000, 07:16

hello Carl
No there is no dme code indicated, but thanks anyway.
brgds
David
Hi David

I guess the DME has no fault codes? I had a simular problem on a different model, and it turned out to be the crankshaft sensor giving erratic signals to the DME. Just a thought..

Regards
Carl

[/quote]

Andy G · 13th December 2000, 10:26

David,
I had a similar fault on my E36 M3, originally it was diagnosed as faulty plugs, but fault reoccured, then the dealer found that the inlet gaskets/rings were leaking, replaced these, things improved, but fault still happened, it turned out to be the swirl pot (I'm sure that's what he said) that had a crack in it, when it cooled down the gap opened letting in air & causing a misfire and poor/eratic running, when it warmed up, the crack closed and subsequently sealing it.
It took 6 months to finally sort out this problem after a lot of elimination work.
Hope it may be of some use!
Andrew.

DAVID NEWTON · 13th December 2000, 10:43

Andrew good day
many thanks for the information i will check the various points out with the local place here
brgds
david

Quote:

Originally posted by Andy G:
David,
I had a similar fault on my E36 M3, originally it was diagnosed as faulty plugs, but fault reoccured, then the dealer found that the inlet gaskets/rings were leaking, replaced these, things improved, but fault still happened, it turned out to be the swirl pot (I'm sure that's what he said) that had a crack in it, when it cooled down the gap opened letting in air & causing a misfire and poor/eratic running, when it warmed up, the crack closed and subsequently sealing it.
It took 6 months to finally sort out this problem after a lot of elimination work.
Hope it may be of some use!
Andrew.

NRL BITURBO · 13th December 2000, 21:23

David,

Just being nosey - where did you purchase your car, was it dealer or private? Have you had it long?

Regards,

Neil
'90 B10 Biturbo (No 0138)

DAVID NEWTON · 14th December 2000, 07:11

Neil good morning
i bought the car from a chap in Norfolk, MCP motor sport, around 5 - 6 weeks ago, apart from this fault I am very happy with the beast, it is number 389, jan 92. I have just contacted Alpina in Buchloe concerning this fault and they advise it could be a general cabling fault, small earth, or something
similar, apparently if the voltage on the management unit is below 13.4 volts it will affect the general running, so plan to take it in tomorrow mornin for just a diagnostic. Hopefully we find something

regards
david

NRL BITURBO · 16th December 2000, 00:43

Hello David,

.... That will be Martin Pearce then (MCP Motorsport). He seems quite a decent fellow. I was all set to buy an '90 Biturbo from him in Sep '99 (if I remember correctly, it was GBP 14,995 with 118,000 km on the clock), but I was unable to complete at the time (nothing to to with Martin).

Having moved to Germany to work, I rekindled my interest in the Biturbo, and hey presto I bought one in late August this year (Nov '90, No 0138, with 160,000 km on the clock - for the princely sum of ..... GBP 5900 equivalent). The car had been maintained as a company car and so was kept in top condition - it also came with a set of winter tyres and rims and the guy also 'threw-in' his mobile phone and the installed car kit. Needless to say, I am very happy with my purchase - even my wife has been won over (ie the 'What do you want to spend several thousands of pounds for on a 10 year old car' question was discussed several times before I bought it).

Are you looking at doing servicing yourself or getting a specialist or Alpina dealer to do it?

Regards,

Neil

DAVID NEWTON · 20th December 2000, 14:38

Neil good day
Sorry for not replying sooner but I travelled last Saturday and have just returned yesterday evening. The car had 98,000 km with a full history, I paid £12,500 for it after a little discussion, you seem to have got a bargain for the price you have paid. Like yourself I am very pleased with the beast just a little disappointed with the occasional misfire, which was not evident when I test drove it for about an hour. He had been running it on 95 unleaded but had forgotten to change the link over in the control box, whether this has anything to do with this problem now I am not sure.
I have recently had a new radio and disc player fitted and the chap who installed it has said that the wiring to the rear speakers had been cut. Martin installed a radio for me plus an alarm/immobiliser, (not him, the electrician he uses), the wiring for the alarm/immobiliser is not the best and I am wondering if he has accidentally "touched" a management system cable and hence this misfire.
Regarding servicing, I dont get much free time so I will get it serviced by the local BMW place for the likes of oil changes but in view of this problem I am actually planning to go to Buchloe and see what they make of it, most probably in mid January.
Regarding wives I know the feeling, I am divorced but when I picked the car up I went round to see my daughters and as you said why does anybody want to spend the money Blah, Blah Blah, you know the rest of the story, still it makes me happy.
Anyway, all the best for Christmas and New Year
Regards
David

NRL BITURBO · 7th January 2001, 13:56

Hello David,

Sorry also for my delay in reply. Happy New Year to you. I'm up near Mönchengladbach, if you are ever this way. I wouldn't have thought that running the car on 95 would have caused that problem (which may be a sensor problem as you say).

Certainly though, car ECUs tend to compute for the worst situation - so although the switch was set for 98, the ECU would have detected that there was something wrong with the fuel and would/should have compensated (that is to retard the ignition). From what I understand of car ECUs, they have a 'memory' which will keep the car runing in this mode, until it is reset. The reset, involves ensuring that the correct grade of fuel is in the tank (and has been flushed through the fuel lines) ie in your case, 98 RON, and the car has been run for several miles. Then, completely disconnect the battery (and ECU cable if accessible) and leave overnight. Reconnect and then the ECU should reset itself and 'map' for the 98 RON fuel (with the Bi-Turbo 'Octane' switch in the correct position, of course).

Whether such an ECU 'memory' effect would cause your misfire, I do not know for sure, but I also run a Lancia Delta Integrale Evoluzione and I know that fellow Integrale 'nuts' have had misfires and lethargic performance. They have reset their ECUs as described and in many cases the problem has gone away.

Quite whether this is a legitimate BMW/Alpina fix I do not know.

Here in Germany, Shell do not sell 98 RON, but they do sell 99 RON (at the same price as others sell 98) - even better.

Regards & do keep in touch,

Neil

[This message has been edited by NRL BITURBO (edited 07 January 2001).]

CarlT · 7th January 2001, 20:55

Hi Niel

The quick way to erase any memory in the system is to disconnect both battery terminals, then connect/tap them breifly. Done. (If you have two batteries as the B12 Coupes, remember to disconnect both...)

Reconnect the battery and drive the car, the ECU will need to learn/calibrate itself over a short periode of time.

Regards
Carl