R129 500SL sudden stalling at 1500 rpm in D

[XG2607]

Hello,


I have a 1991 MB 500 SL, Euro version with KE Jetronic. It has the factory Anti Theft Alarm

It has developed a failure where it just cuts out when it reaches 1500 rpm in Drive. Just after dying it can be normally started but stalls again at 1500 rpm. It does not happen in P, N or R. It starts and idles normally and this failure started happening after about 3 weeks of sitting in the garage. It had its old Bosch Bloctronic alarm removed recently but I did not feel any strange things after this removal. This alarm was additionally installed to the factory ATA back in the day.

I read the codes with a flash counter but found no errors whatsoever…

Has anyone had something similar happen?

Thanks,
Fitz