Any ideas how to solve this problem?
My 1990 300SEL has intermittent problems accelerating from a stop (or while in 1st gear). It does not occur every time, but some days it is intolerable and dangerous when pulling into traffic.
Symptoms: When accelerating from a stop, there is coughing and sputtering for many seconds (feels like a fuel problem) before it "takes" and accelerates. This does not occur when accelerating in higher gears (2+), and is intermittent and completely unpredictable as to when it will happen next.
Trial and error: My mechanic and I have tested and tried the following, with no luck in resolving the problem:
1. Replaced the fuel injectors, fuel distributor, and fuel pump.
2. Replaced the rotor, distributor cap, and checked the wiring harness.
3. Tested the main computer.
4. Checked the entire fuel system - verified pressure.
5. Replaced the cold start module (the problem tends to be more prevalent in cold weather).
I love this car - it has only 100k miles and has run beautifully for many years. Because the problem is intermittent, it is very difficult to trace back to root cause and I am at a loss with regard to "throwing" more parts into it to see what works.