Rev hang auto to manual

[Mpopaj]

After swapping my coupe to 6 speed I have been experiencing terrible rev hang. I have read on the forums that this is common after an auto to manual swap but have seen different info on the solution. I behave seen some people say that the fan needs to be swapped between the autos and manuals and I have seen some people say the clutch switch is improperly wired. I have even seen somebody make a modification to the icv but this doesn’t seem like it would be the correct solution. What is the general consensus now? If it is my clutch switch, can someone link the proper wiring?

 

[Aquasurf]

Well, I do not have an answer for you but as a retired vehicle compliance engineer but I looked into the cause of rev hang in other cars and wrote about my findings here. They may provide some explanation.

 

[NZ00Z3]

Where in the World are you located?

Which engine/DME do you have?

Have you coded the DME for the manual transmission?

If you are in the USA, there are 2 clutch switches in the Z3's:

• S325 for the starter imobiliser (clutch pedal in to start)
• S32 for DME control and cruise control (clutch pedal all the way out)

It is S32 that you need to add to stop the Rev-hang. Depending on the DME, it may also need coding to the manual transmission.

 

[Mpopaj]

Yes I am in the USA and I have a m52tub28. I believe these only came with the Siemens ms42. I don’t think they need to be coded so I’ll check out the s32 switch.

 

[NZ00Z3]

The S32 is the recongised fix for the M52TU rev-hang. You can see it working in the DME data if you use INPA.