Weird cutting out problem
 

I've got a 1990 740 2.3 Auto. The Lambda light is on, on the dashboard, indicating a fault. The symptoms I have are as follows:

Car starts and ticks over perfectly and pulls away with no problems until I put my foot down and it reaches approximatley 3000rpm, this is where the engine dies, it's almost as though I've switched the ignition off but when I back off the throttle it comes back to life and carries on as normal until I try to boot it again. Any ideas?

Thankyou,
Paul.

RE: Weird cutting out problem
 

Have you done any work on it lately?

RE: Weird cutting out problem
 

Hi,

No, I've not touched it. I bought it like this. When I bought it the guy said that that very day the light came on. I wasn't too bothered as it drove ok until you booted it.
I'm not all that bothered about it as it's only a temporary car whilst I do some restoration work on my classic but it would be nice to sort it out as it is a bit of a pain in the arse when trying to overtake!

Cheers,
Paul.

RE: Weird cutting out problem
 

Check and make sure he didn't have the rear main seal replaced.

RE: Weird cutting out problem
 

Ok. Will do but for what reason? What are you thinking could be the problem?

Paul.

RE: Weird cutting out problem
 

If the flywheel was installed wrong then it will act like that.

It could also be a bad Maf or speed sensor.

RE: Weird cutting out problem
 

MAF sensor or speed sensor..... ok. By "speed sensor" do you mean engine speed sensor/crank sensor?
As for the flywheel, can't answer that but will bear it in mind if all else fails.

Many thanks,
Paul.

RE: Weird cutting out problem
 

The fact that it happens at one particular throttle setting makes me think you have a bad place in the throttle position sensor. You can attach a voltmeter and with the key on you can slowly open the throttle voltage should slowly increase also. If you find a bad place you have found your problem. You can also unplug it an check it with a ohm meter. It should go up smoothly with no bad places.

RE: Weird cutting out problem
 

Yes I mean the crank sensor for the speed sensor. Also if the flywheel is damaged it could do that as well.

RE: Weird cutting out problem
 

How mutch fuel is in the tank? Tryed to fill it upp?

you have a Fuel pressure problem, check the pump in the fuel tank! or the pump under the car. That is the problem :)