Super rich and lumpy + poor throttle response (video)

[tuna]

Hi guys so my car has been running rough, but has got gradualy worse over the time, especialy during the colder seasons. So the car will start fine when i turn the key, no hessitation what so ever, however, once is started the idle is all over the place (levels out once warmed up). If i put small rev's the throttle response has nearly a second delay and when the revs come back down the car will almost stall. And on top of all this, (not sure if its related or not) the car runs hella rich! The chaps at the garage keep telling me its the MAF filter however i've replaced that twice, wich second hand ones and its still the same Im not great at explaining things, hence why i uploaded a video of this issue on the tubes. Sorry about the audio quality, its off my phone! Oh and thanks for your time!



Dan

[bmw9818]

its an m40, mine was like that, iirc i changed my leads to oem ones, gave it service, and one of the main things which made a difference was the fuel lines, try start it tomorrow morning and if you can see any leaking on the passenger side of of the engine look underneath to see if its leaking out and drippin onto the gearbox,

after i changed the lines it started up so much better, it was still a bit sticky still on a very cold morning and needed a few seconds to idle before i moved otherwise it stalled, but it was a bit better,

other things are your blue and brown temp sensors, icv valve but it should be bypassed when throttle is pressed anyway, couldnt hurt to clean it out though,

[Grrrmachine]

I would help you, but you stickerbombed your strut brace...

But if I WERE to help you, I'd suggest that your throttle position switch has filled up with oil and become clogged, to the point where the ECU doesn't know the car is at idle

http://www.e30zone.net/e30zonewiki/inde ... ion_Switch

Also, your car doesn't have MAF, it has AFM.

[tuna]

thanks chaps, ill check those things in the next few mornings that arnt so cold. And grrrmachine i apreciate what you say and trust me when i get a real engine in there ill take the looks of the bay a bit more seriously

[tuna]

Okay so i removed the TPS and it looks to be okay, oil has built up inside the shaft hole but dosent look to bad. The TPS still clicks when the throttle is touched however i dont have a resistance meter so i cant realy see if its working properly. To be honest im not realy sure what im looking for in the TPS as to me it looked okay. Is there a way of opening it up to give it a good clean? I also noticed once taking of the rubber boot off, there was a small amount of oil resting on the bottom of the inside of the throttle body, no idea if this is normal though. Ill take a look at the fuel lines at a later date when i get more time.

[TPS]

I would clean out the ICV & Throttle Body with Carb.Cleaner, to start with.

[Speedtouch]

It also sounds like your exhaust is blowing, so check for leaks as they affect the back-pressure, leading to lumpy running.

[tuna]

Thanks will get some carb cleaner and check for any blows!

[mcbonio]

Just had a listen.... only one solution really.... Pull the engine out and drop a big 6 pot in.

[tuna]

Mcbonio, thats a fantastic idea, just need some cash

[tuna]

Okay guys anything else i can check whilst everything is un-attached and im waiting for the carb cleaner?

[Speedtouch]

Check all exhaust flange gaskets for leaks. Also try spraying WD40 around the inlet manifold gasket; if it briefly raises the idle speed, then you have an air leak.

[mcbonio]

Maurice... you said flange..

[spacechimp]

Check the air intake hose.. The inside bend hides splits which can cause bad idle problems.. It's an easy one to check.. The easy ones always catch you out

[tuna]

Okay everything you lot mentioned is all checked and seems to be okay, after cleaning the icv and throttle body it finds the idle point faster on a cold start up however the poor throttle response still remains allthough it seems to be a bit better after giving it a quick test drive. The car however still stinks of unburnt fuel... Just seems this car is forever running rich >.> I took another video of how its running so i can upload it to the tubes if any of you lot think it will help Thanks all!

[Speedtouch]

Sounds like you need to get yourself a multimeter for Christmas and check the blue temperature sensor is working as it should.

[tuna]

Sounds like an awesome pressi, will let the rents know !

[soul4t]

Hi tuna, does the car still smell of unburnt fuel when warm? Has it had an MOT recently, or since this problem, if so do you have the CO% readings and H-C reading? Yup Multimeter is quite essential for checking components and wiring!

[tuna]

Soul4t, yes it has had a recent MOT but the place i took it to dont give you the readings, just pass the car, and yeah the car passed it, although they said, 'we gave it leway because it is an old car'. The car always smells of unburnt fuel, warm or cold. I could pull up to a set of lights with my window open and as soon as i come to a stop i can smell it. Also i've been told they it can be smelt from inside the car behind me.

[Brianmoooore]

although they said, 'we gave it leway because it is an old car'.

Tell them it's a BMW, not an "old car"!!!!!!!! It should be capable of producing the same gas figures as it did when it left the factory, and should be well within MOT limits.
If it's not, then there's a definite fault, which needs sorting, not ignoring.

[tuna]

thanks brian, is there anywhere i can get the factory emmision figures for a m40b16 so can make sure its running right, just gotta diagnose the issue first...

[Speedtouch]

Scroll down to page 11 of this:

http://bmw-teremki.kiev.ua/images/stori ... e28e34.pdf

[tuna]

Nice find thankyou speedtouch