I have an 1986 420SEL and it did something different today. The ABS check light came on and the RPM’s went up to about 1400 for about 30 seconds then the light turned off and the RPM’s went back down. Can anyone tell me what would cause this, beyond that the car runs fine. This car has been parked about 5 months I don’t know if that had anything to do with it, but like I said other than that it ran just fine. It did it two times both right after I started the car, but that was two times out of 5 starts, I was out running errands, but it did not do it the first time I started the car today. Any help is appreciated. Thanks.