Bmw z3 lumpy ide

[2bmws]

In a previous thread, i said about the car smelling of fuel and lumpy idle i had put a new thermostat and it was a bit better,
I had a friend up today to have a look at it whos a mechanic and said that the catalytic converter had been removed so it was
"Straight piped" and said that he thinks this is causing the lumpy idle and the fuel smell as the lambda sensor isnt reading properly.

Do you guys think this is plausible.

Also had a ring round for a cat and could not buy one locally some car places dont even list one for it.
Carparts4less and eurocarparts dont list one either which i thought was crazy.
I managed to buy a new one off ebay so will be here tuesday to fit

 

[Kenny101]

Hiya

What year / engine ?

 

[2bmws]

Its a p reg 96 1.9 twin cam

 

[Jjim]

Sounds like it could be a split air intake hose, as this is a common issue on the 1.9

Often a split on the bend of this large pipe - usually between the ribs

Also it’s common for this smaller pipe to have a split at either end

 

[Kenny101]

As jjim has said its more likely to be a split hose/bad sensor

i Have run a decat on my 97 m44 For about a year now and did not notice any change in idle when fitted so i doubt its that

 

[2bmws]

That smaller pipe you have circled does have a split, ive replaced the big one with a new item, do you know what that pipes called so i can get a new replacement please and is it a big job.
Thanks

 

[Jjim]

That smaller pipe you have circled does have a split, ive replaced the big one with a new item, do you know what that pipes called so i can get a new replacement please and is it a big job.
Thanks

It’s a quick job, pull off at both ends and push the new one in.

Not sure if the part number. I got a used one from @spurs fan in a coupe

 

[colb]

Splits or holes in the rubber hoses will cause idle issues and mess up fuel trims as the car tries to compensate for the unmetered air entering as it thinks its running lean hence the smell of fuel. These engines require a good sealed intake and vaccum system to run correctly. https://www.realoem.com/bmw/enUS/showparts?id=CH71-EUR-06-1996-Z3-BMW-Z3_19&diagId=13_0418 for the parts you will require. If you go to the home page enter last 6 letters and digits of your Vin number to access the listing of parts for your particular car. I always use Sopers BMW at Lincoln for parts they accept Zroadster forum and will give you a discount and post items to you, they are very good to deal with.
Just noticed your in Wales, if you are in the South our little group of Zshedders get together to do odd jobs on our cars, we have diagnostics and a smoke tester in our tool kit if your near us.

 

[2bmws]

Thanks for that fellas, but it doesnt show the smaller pipe coming off the intake pipe.
Thats the one on mine thats split

 

[2bmws]

Would it be part 18

https://www.realoem.com/bmw/enUS/showparts?id=CH71-EUR-06-1996-Z3-BMW-Z3_19&diagId=13_0403

 

[2bmws]

Im in newport south wales

 

[spurs fan in a coupe]

If you need a second hand one let me know

 

[2bmws]

What other vacuum pipes are on this engine please

 

[colb]

https://www.realoem.com/bmw/enUS/showparts?id=CH71-EUR-06-1996-Z3-BMW-Z3_19&diagId=13_0418
Possible its Number 6 in this diagram as its shown with the connecting stub and other intake hoses.
I am in Rogerstone so very close by the look of it.
If you think you may have air leaks elsewher I can smoke test it for you which works great for finding any leaks have to wait till lockdown ends.

 

[2bmws]

Thats great of you colb, im in malpas so no definetely not far lol

 

[2bmws]

Bit of an update put a new cat on, exhaust and lambda sensor seems a bit better. The old cat all the gubbins inside had either colapsed or removed either way sounds a lot better and a bit more pokey now

 

[IanBrown]

Bit of an update put a new cat on, exhaust and lambda sensor seems a bit better. The old cat all the gubbins inside had either colapsed or removed either way sounds a lot better and a bit more pokey now

Hi

What make cat did you put on? Mine needs replacing and an OEM one is c. £1k! Ouch!

 

[2bmws]

https://www.ebay.co.uk/itm/332261002276

This one i bought