S54 Engine Hesitation from Idle & Constant Throttle Input

[Tcochrane92]

I've read a couple threads on this, but apologies as I didn't want to read through dozens of pages to find the answer

My Z4m (69k miles) has engine hesitation when you blip the throttle. Happens from idle & also at higher revs. Especially noticeable when using cruise control at cirva 50mph - the car feels like it lurches when the throttle opens slightly to maintain speed.

Also when holding constant throttle input (small input, maybe 5% throttle), the engine lurches and hesitates unevenly.

I'm thinking it could be injectors, am I thinking along the right lines?
No fault codes

Cheers

 

[Babw]

I had similar issues and cleaning the throttle bodies, ICV and replacing the TPS's cured the problem. (Did all this while installing my Karbonius intake and installing the Evolve Alpha-N map so potentially it's one or a combination of all of these that cured it.)

 

[crustyclown777]

TPS solved it for me. (Engine side)

 

[Kern47]

Had similar problems on other cars...
A bottle of Forte injector cleared it up for me, not had it with my S54 but that could be a good first port of call to see if it solves your problem...
Worst case scenario you've still got the problem but with (presumably) cleaned out fuel system for ~£10

 

[ph001]

Yep, throttle position sensor would be my guess. The S54 has two, one is easy to get to, the other isn’t.

 

[Tcochrane92]

Thanks for the help guys. I'll pick up some injector cleaner and see if that works

Otherwise, which TPS do you recommend changing?

 

[mpm]

The TPS further back tends to go more often due to the heat, it breaks down the internals.

 

[Tcochrane92]

Can someone advise if this is the right part please?

https://www.eurocarparts.com/ecp/c/BMW_Z4M+Roadster_3.2_2006/p/car-parts/fuel-and-engine-management/engine-parts/engine-management-sensor/?421110030&1&37f2d4ef51d269e83ceb181048a958bcba71ed6d&000576

 

[Matt.13]

Looks the right one to me

 

[Spaniarduk]

[ref]Tcochrane92[/ref], are you going to replace it? The one by the throttle actuator? Let us know how you got on and what the result was

 

[srhutch]

Can someone advise if this is the right part please?

https://www.eurocarparts.com/ecp/c/BMW_Z4M+Roadster_3.2_2006/p/car-parts/fuel-and-engine-management/engine-parts/engine-management-sensor/?421110030&1&37f2d4ef51d269e83ceb181048a958bcba71ed6d&000576

Try carparts4less.co.uk same company but cheaper prices as long as you can wait a day or two for delivery :wink:

 

[Spaniarduk]

Can someone advise if this is the right part please?

https://www.eurocarparts.com/ecp/c/BMW_Z4M+Roadster_3.2_2006/p/car-parts/fuel-and-engine-management/engine-parts/engine-management-sensor/?421110030&1&37f2d4ef51d269e83ceb181048a958bcba71ed6d&000576

Try carparts4less.co.uk same company but cheaper prices as long as you can wait a day or two for delivery :wink:

Jeez... under 50 quid for exactly the same item!! And clearly, the website *is the same*! Thanks [ref=#006600]srhutch[/ref],

 

[Tcochrane92]

[ref]Tcochrane92[/ref], are you going to replace it? The one by the throttle actuator? Let us know how you got on and what the result was

I'm going to try some injector cleaner tomorrow - can't hurt.

Plus, I've just ordered the TPS from srhutch's recommended website - thanks!

I'll replace the TPS next weekend / weekend and update the thread on my findings.

Just to be sure - is it this part?

https://cdn4.pelicanparts.com/techarticles/BMW_Z4M/28-FUEL-S54_6_Cylinder_Engine_Throttle_Body_Actuator_Replacement/images_small/pic04.jpg

Are these clips re-useable?

https://cdn4.pelicanparts.com/techarticles/BMW_Z4M/28-FUEL-S54_6_Cylinder_Engine_Throttle_Body_Actuator_Replacement/images_small/pic01.jpg

Thanks all

 

[Tcochrane92]

So I replaced the throttle position sensor on the front of the engine (the one most accessible) and the car instantly feels better. The hesitation appears to have gone, the throttle feels very responsive and it revs very cleanly now.

I've also put some injector cleaner into the fuel for a bit of extra help.

If I get any more hesitation, I'll replace the other TPS under the intake chamber too

Thanks all for your advice!

 

[Spaniarduk]

[ref]Tcochrane92[/ref], excellent news! I feel tempted to spend the 50quid and replace it in mine. I have some hesitation between 2300 and 2800rpm and half throttle. Precisely the rev range where you cruise along.
I'm also planning on doing the valve clearance check in the spring, which I feel it's due at 30k miles.

Keep us posted!

 

[Tcochrane92]

[ref]Tcochrane92[/ref], excellent news! I feel tempted to spend the 50quid and replace it in mine. I have some hesitation between 2300 and 2800rpm and half throttle. Precisely the rev range where you cruise along.
I'm also planning on doing the valve clearance check in the spring, which I feel it's due at 30k miles.

Keep us posted!

Drove the car again this morning and it feels 100% better. Night and day difference really.
For the sake of 50 quid and 5 mins labour it's well worth it!

 

[Babw]

These cars have 3 TPS's by the way; one at the front of the engine, one under the intake manifold and the last in the throttle pedal.

 

[DevonPaul]

Can someone advise if this is the right part please?

https://www.eurocarparts.com/ecp/c/BMW_Z4M+Roadster_3.2_2006/p/car-parts/fuel-and-engine-management/engine-parts/engine-management-sensor/?421110030&1&37f2d4ef51d269e83ceb181048a958bcba71ed6d&000576

Try carparts4less.co.uk same company but cheaper prices as long as you can wait a day or two for delivery :wink:

If using carpart4less, go to their homepage where they always have an offer code. Today it is winter19 and gets 13% off everything, tomorrow it could be 10% or 20%

I wanted a battery a while back and it varied by £20 over the course of 4 days.

Paul

 

[Muckinonthesofa]

[ref]Tcochrane92[/ref], excellent news! I feel tempted to spend the 50quid and replace it in mine. I have some hesitation between 2300 and 2800rpm and half throttle. Precisely the rev range where you cruise along.
I'm also planning on doing the valve clearance check in the spring, which I feel it's due at 30k miles.

Keep us posted!

Drove the car again this morning and it feels 100% better. Night and day difference really.
For the sake of 50 quid and 5 mins labour it's well worth it!

Have you got the part number, I'm thinking of getting it done as part of my next service?

 

[Papa_Zee]

Before changing the part, I would try the reset steps:
https://youtu.be/5ptZuIIVBfQ

Seemed to help my 2.0.