fallin on your face hurts
 

I have an 86 300E, I just did a full service and tune up and still when i push the throttle off the line it will fall on it's face everynow and then. anybody know what might cause this?

Rotor burnt.
Wires bad.
Fuel pressure fluctuations.
Electrical fault in engine wire loom.
Bad OVPR.
Faulty Fuel Distributor.
Sticky Air Flap Piston.
Acceleration enrichment module failing.
Bad engine ground.
A/C ripple from alternator.
Ignition switch faulty.
Any, or combination of above.

Acceleration enrichment module failing.

Where is this at? If the car had a carb, I would say the accelaerator pump is bad.

Forgot one other thing...sticking or incorrectly set idle micro switch.

Acceleration enrichment module failing.

Where is this at? If the car had a carb, I would say the accelaerator pump is bad.

Same thing, but electronic.....small black thing on side of CISe air meter head.
Otherwise known as a air volume meter sensor. It sends a variable voltage back to the ECm for air flap position.

There's been a post here on it's function and setting some while ago.

http://www.landiss.com/mixture.htm