Posting here because my thread over there: http://www.benzworld.org/forums/w202...ne-1996-a.html
is not getting much incoming information.
1996 C280 (W202), picked it up a few weeks ago. Have replaced everything that was throwing a code, including MAF, and got the vacuum leak that was messing up the transmission shifting fixed.
The M-B data port under the hood won't communicate with my mechanic's super-duper code reader, so we're just running on OBDB II codes.
When the A/C is on, trying to take off fast from a dead stop does almost nothing. The car just sounds like a manual transmission in fourth gear going 10 miles an hour and wide open throttle--the sound changes a little, but unlike a manual being lugged too slow, it often never picks up engine speed, and will rarely stall. Backing off the throttle and giving it a tiny bit, feathering it back to zero and then easing back up to no more than 1/4 (ish) throttle often persuades the engine to pick up and give some power.
This is whenever the starting point is below about 800 RPM. At 800-1,000 RPM, it will be a little slow taking off but will go. No problem if rolling and the engine is at or above 1,000.
This gets worse the hotter it is outside. The delay is longer, and feathering the throttle might not even work. It will even stall sometimes. Noticeably worse at 100 F, gets almost un-driveable above 110 F. When it's that hot, it is sometimes hard to get the RPMs up above 1,000 even in neutral.
Then I discovered that if the A/C is off (including just activating the EC button), there's no problem at all.
Fuel economy is also pretty bad IMO: 17 mpg around town, barely 21 on the freeway at 75 mph.
One person has suggested checking fuel pressure at the injector rail, but I haven not yet been able to connect with a gauge yet. But since it never stalls at speed and misbehaves ONLY at the transition from idle to supposed to give power, I don't understand how a fuel pump or filter could be involved with this misbehavior.
So before I throw parts and money at it (like a TPS that is bad but not generating a code...), I would really like some more suggestions about what to check first.