Hesitation in acceleration

[325es86]

I own an 86 325es. Only have had a couple of months. The car idles rough in warm/hot weather. Has a definite, almost pulsating hesitation when accelerating. Hesitation most notable when engine is cold or air temperature is hot. Best driving so far has been when air temperature was 55 degrees and engine was warm.

Changed plugs. Plugs were clean. Looked great. Also changed fuel filter.

Is it possible that the problem is the O2 sensor? Is there a separate air temperature sensor or is that part of the mass flow sensor?

Help appreciated.

 

[pjgonwa]

I had a slight hesitation on accelleration and sometimes while at running speed. I found the spark plug wires to be the culprit.

 

[Ben]

if its a pulsating hesitation, it sounds like 1 or 2 cylinders are not firing right. Like pjgonwa said, get new plug wires and if that doesnt help, do a compression test. One very easy way to see if your plug wires are really bad is to turn the car on at night, open up the hood and rev the engine. if they're cracked really bad, you'll have a nice light show. also check the distributor cap and rotor.

 

[epj3]

I'm getting the same thing but it only happens on the first few times of going from idle to accelerating. annoying as hell because the car sputters as if it's hitting the rev limiter (it sputters that fast).

 

[AutoXfreak]

I have the same problem as all of you guys, I am damn near my wits end with it. I have replaced more that I can remember! I might as well take the motor apart and rebuild and replace every sensor and wear Item!!!