Full throttle hesitation

[spit64]

The car is a E320 1994 104 engine, and the problem is when i give full throttle at a stop sign the car stumbles a few seconds and then take off. When giving full throttle normal speed the car hesitate and jerking. This happens during the summertime and not in the winter i suspect the air mass sensor but when I disconnect the cable to the air mass sensor there is no difference in performance. If there is a throttle position sensor the problem should be in the winter too. The wiring harness is brand new. I will also check the ECT sensor.