BMW e39 running problem

wotzgoingon

Hi all so my 1998 e39 520i had a starting issue which turned out to be a bad starter. So I replaced it with a new one and it starts straight away but now there is a problem.

So I start the car and the car revs up and then down and cuts out. Anybody any idea on what could be the problem.

Also I had to disconnect a few things including taking out the intake manifold the throttle body, mass air flow sensor.

Foxhole Norman

wotzgoingon wrote: »

Hi all so my 1998 e39 520i had a starting issue which turned out to be a bad starter. So I replaced it with a new one and it starts straight away but now there is a problem.

So I start the car and the car revs up and then down and cuts out. Anybody any idea on what could be the problem.

Also I had to disconnect a few things including taking out the intake manifold the throttle body, mass air flow sensor.

Plug them all back in :pac:

wotzgoingon

If only it was that easy. :pac:

Captain Slow IRL

Sounds like you have an air leak somewhere, you're gonna have to get a good look in and check you've everything installed right. You may have to go stripping out again if there's nothing blindingly obvious.

wotzgoingon

Captain Slow IRL wrote: »

Sounds like you have an air leak somewhere, you're gonna have to get a good look in and check you've everything installed right. You may have to go stripping out again if there's nothing blindingly obvious.

I know, I was hoping it wouldn't have to come to that.

Captain Slow IRL

You may have a split pipe/hose that was caused when you took it out - keep an eye out for any damage when you're investigating.

wotzgoingon

Captain Slow IRL wrote: »

You may have a split pipe/hose that was caused when you took it out - keep an eye out for any damage when you're investigating.

Will do. Cheers.

Foxhole Norman

Is everything currently plugged in? If so, I'd bet on your MAF. Plug it out and see if it runs.

wotzgoingon

Foxhole Norman wrote: »

Is everything currently plugged in? If so, I'd bet on your MAF. Plug it out and see if it runs.

What happens when you run with it plugged out?

Foxhole Norman

wotzgoingon wrote: »

What happens when you run with it plugged out?

Usually it'll run fine, maybe a bit shaky and may throw a light but if your MAF is faulty it will start and die like that, I had it on my 528i.

wotzgoingon

Foxhole Norman wrote: »

Usually it'll run fine, maybe a bit shaky and may throw a light but if your MAF is faulty it will start and die like that, I had it on my 528i.

Really, more money to waste so. I replaced the alternator, starter and now MAF. Does it ever end.

wotzgoingon

I'm thinking it could be the MAF alright as it was raining the day I was working on the car and I just left it lying on top or the radiator so maybe the rain damaged it.

But then on the other hand it may be something else. Thanks for the help anyway.

wotzgoingon

Foxhole Norman where did you get your MAF from. Just looked up the price of them and they are seriously expensive.

Scrappy it must have been? No?

Foxhole Norman

wotzgoingon wrote: »

Foxhole Norman where did you get your MAF from. Just looked up the price of them and they are seriously expensive.

Scrappy it must have been? No?

You can get new units fairly cheap from here:

http://www.maf-shop.com/index.php/cat/c8_MAF-BMW.html/XTCsid/085e4df8cd96fd6178b2b7d465711f87

Mandzhalas

Car should run without maf. I was drining with mine disconnected for couple of weeks, when ibforgot connect mine. You would not notice difference. E39 525i

Foxhole Norman

Mandzhalas wrote: »

Car should run without maf. I was drining with mine disconnected for couple of weeks, when ibforgot connect mine. You would not notice difference. E39 525i

Can confirm the same, also a 525i.