Shifting hiccups and the cure.
 

I bought a 560 SEC about 8 weeks ago and since it has had a hiccup when shifting gears at full tilt, foot down. It would do this only if I was getting all over it. It would NOT go past about 4700 RPM and then stutter/Hiccup trying to shift into the next higher gear.
I ran thru the gears several times to try to figure out what was wrong. Tranny shifted/shifts like a dream IF I take my foot out of it the merest little bit.
I finally figured out that it wasn't the tranny and that it felt like fuel starvation. Someone on another forum suggested that my KAE FPR might be the cause as they go south very quickly. I also thought that maybe a partially plugged fuel filter.
Well today I replaced the KAE FPR with a real MB one with the correct number and let me say this;

HOLY CRAP!

What a Difference!

Now the car will red line at 6000 RPM and shifts out of gear at or above the marks on the Speedometer, (I haven't had the guts to keep my foot in it until it shifts into 4th yet,(125 MPH on my Speedo) mostly due to lack of hwy space and traffic.) I am sure that it'll shift into 4th just fine when the time comes. Iwas pretty happy with the car's performance before, but now....WOW!

My 380SE is experiencing the exact same anomaly and it's KAE FPR will be replaced ASAP.

What is a KAE FPR?

KAE is an after market mfg. of electronics for MB's and maybe other makers too.
FPR = Fuel Pump Relay.