I have a 1995 500SL with 47,000 original miles, ran great everything worked. Got it home and replaced the engine harness as I was aware of the history, ran great for more 7 months with no problems.

Now after it warms up, the engine backfires and runs poorly and will not start after being shut off. When it cools down, it starts again. I replaced the crank position sensor and did not resolve the problem.

What next?