Z3M S50 issue

[Z3Mroadster]

Hello!


Idle ok,power ok,

but after driving and turning off the hot engine and driving again after 5-10 minutes, the car jerks up to 2500 rpm. After a few minutes of driving everything is ok. This has been going on for several years. There are no codes.

Thanks!

 

[Mark Gutteridge]

Spark plug breaking down?

 

[Z3Mroadster]

Sparks don't have any issue...

 

[Ianmc]

Sticking throttle cable?

 

[Nodzed]

Sounds like fuel evaporation/pressure? But what could cause it???? Could it be a fuel pressure issue? Have you ever changed the fuel filter?

 

[Z3Mroadster]

Throttle cable new and fuel filter new!

 

[Althulas]

Soldering to the solenoids sound? Reason I ask as I was messing around that area and caught my cable and the revs fluctuated raising and dropping as I caught it. Something I’m adding to my list to investigate.

 

[Mark Gutteridge]

Could also be a vanos issue, common on the s50.

 

[Z3Mroadster]

Soldering to the solenoids sound? Reason I ask as I was messing around that area and caught my cable and the revs fluctuated raising and dropping as I caught it. Something I’m adding to my list to investigate.

But then he wouldn't have the power, would he?

 

[Z3Mroadster]

Could also be a vanos issue, common on the s50.

Vanos have 100 bar pressure!

 

[Nodzed]

Vanos have 100 bar pressure!

Thought it should be 250?

 

[Mark Gutteridge]

120psi Steve (mr vanos) told me

 

[Z3Mroadster]

M

120psi Steve (mr vanos) told me

No!

Correct is 100 bar !!!

 

[Mark Gutteridge]

ok, 100 bar, all I know is having my vanos replaced and setup correctly was the best money I've ever spent. Different car entirely.
I wish id had it sorted years ago.

 

[Althulas]

But then he wouldn't have the power, would he?

can still have the power but an intermittent fault. I’m most likely wrong but Just an item to check and rule out.

 

[Nodzed]

M



No!

Correct is 100 bar !!!

OK calm down

 

[137699]

Could be something like a camshaft rotation sensor / TDC etc?

 

[Z3Mroadster]

Could be something like a camshaft rotation sensor / TDC etc?

How check?

 

[Pingu]

Download Testo, record the data until you get the problem, then check the data.

 

[Aceman]

ok, 100 bar, all I know is having my vanos replaced and setup correctly was the best money I've ever spent. Different car entirely.
I wish id had it sorted years ago.

I did tell you to get it done many years ago.