1995 E320 Late Shifting--Throttle Actuator, Vacuum Modulator--Other Ideas?
 

Latest saga...I drove my grandmother's 1995 E320 for the first time in a while yesterday and I noticed some unusually late shifts around 3000K RPM even with light throttle input. I initially suspected an out-of-adjustment bowden cable since I had opposite symptoms (early premature shifts around 1500K) in the past. Unfortunately, the cable still seemed taut and, even more strangely, the car shifted totally normal after 20 minutes of prolonged driving. I shut it off for a few seconds to see if it was a warm/cold thing but I experienced the delayed shifts again...in other words erratic but occasionally resolved after extended warm-up.

Interestingly, the check engine light turned on about 4 months ago. I read the "blink codes" as 2, 4, and 6 but I figured I needed the homemade code reader or a trip to the indy to make more sense out of it. Now that I think of it, could there be a vacuum leak or cracked vacuum modulator at the transmission responsible for both the symptoms and the light?

Also...about 1 year ago, the car lost total power on the interstate with the cruise on. The ASR light illuminated and I attributed the symptoms to junk wiring in the throttle actuator. I have been scouring the local pick-n-pulls for an updated ASR ETA since then without much luck. Could the late shifts be a result of a deteriorating throttle actuator?

Let me know what to chase down first. Not crazy about this problem since 3000 RPM is a little hard on a cold engine first thing in the morning. Thanks for the help in advance.

Luke

Your car has a switch on the place where the bowden attaches which causes the transmission to shift late when the engine is cold. This accelerates the warm up time.

That maybe acting up.

Thanks for the heads up...is that switch on the driver's side of the engine compartment or at the transmission itself?

On the transmission end of the cable