1990 BMW 325 Hesitation

TEDDYMPR

MEMBER
1990 BMW 325
6 CYL
2WD
MANUAL
76,800 MILES

My car still having a hesitation problem after the mechanic put new spark plugs and wires, they clean the air flow meter, clean the injectors. The hesitation is more frequently when the car is warm, you don't feel it that much when the car is cold. What else can cause the hesitation

Thursday, July 10th, 2008 AT 4:15 PM

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Engine Hesitation

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires

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Thursday, July 10th, 2008 AT 4:31 PM

DOCHAGERTY

MECHANIC
9,603 POSTS

There is a connector under the intake manifold that often gets corroded and causes this issue. The coolant temp, injection and temp gauge data flow through it. It is round and passes through a bracket that is bolted to the block just above the oil pan below the throttle body.

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Thursday, July 10th, 2008 AT 8:26 PM