» View Question

Joe77 3/20/2015

1996 Buick Regal Custom 6 Cyl 3.80L


I'm experiencing a rough Idle and warm starting issues in 1996 Buick Regal. Possible fuel system issue...again?

This is regarding my 1996 Buick Regal with 3800 engine.
Last fall I had fuel pump and filter replaced after intermittent warm starting issues. Issues got worse, but mechanic couldn't replicate issue until the car began to stall.
Now, 5 months later I seem to be experiencing some similar issues. I've noticed a rough idle at times and problems trying to start after sitting for a medium length of time (maybe 60-90 minutes). Starting issues go like this: It will crank ok and fire but rumble and sputter at low RPMs for a couple seconds before revving up to a normal range. It died once but started up right after. Cold starts are perfect.
It seems like it's a fuel issue again?...but it seems hard to imagine it's the fuel pump since that was just replaced. . I'd like to bring it in but am doubtful the mechanic will be able to recreate the issue since it's intermittent. There are no codes. Any advice?

1 Answer


Jimm 3/20/2015

First step - have the stored fault codes or check engine light scanned - for free - at any local auto parts store; Advance Auto, Auto Zone, NAPA. Then, post a reply as 'add answer' with the specific code for more assistance.
There may be a fault code stored in the OBD memory which may not be displayed as a check engine light.

Do not skip this important first step - there are literally hundreds of possible fault codes. Avoid wasting/ throwing money at the problem.

Possible Causes of Engine Hesitation or Stumble:

Dirty fuel injectors (cleaning the injectors often fixes this)
Dirty air filter (change filter)
Dirty / clogged fuel filter (change filter)
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


Answer this question

( characters left)

Follow Question

what's this?