Skip the auto shop - Our mechanics make house calls

Q: Sputtering, misfiring, power loss and gain

asked by on

My car has the 3.4L when it warms up it misfires power goes in and out and when you give it more than 1/4 throttle it acts like it either gets to much or not enough gas and when it hits overdrive it shutters. What could the problem be?

My car has 217000 miles.
My car has an automatic transmission.

Hey there:

There are usually two different mechanical problems that cause the symptoms you’re describing with your Pontiac Firebird. The first and most common is a problem with the ignition coil, (especially in mid-90’s GM V-6 engines) or due to problems with fuel injectors that are dirty or corroded with excess carbon buildup from the EGR system.

If the Check Engine Light has illuminated on the dashboard, a good bet would be to contact one of our local ASE certified mechanics who can download any error codes stored in the computer which will give them a good indication as to what’s causing your engine misfire.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: No power when hot. 1999 Chevrolet Tahoe

Hi there, thanks for writing in about your 1999 Chevrolet Tahoe. You mentioned you replaced the throttle sensor, but there are a few different sensors related to this. Assuming you replaced the throttle body sensor and not the throttle position...

Q: I have a 94 RAM b250 van,the driver side is making a loud clunking noise when turning or driving.upon inspection,the knuckle assem

Worn ball joints and tie rod ends could account for the noise. If you have CV axles in the front, failure of the outboard CV joint would cause similar noise. To have those suspension components inspected, and replaced as needed,...

Q: Misfire on cylinder 1 causes spark too rich or lean fuel levels

Hello there, the P0301 Cylinder 1 misfire is a common code on your 2002 Chevrolet Trailblazer. When a misfire code is seen it is telling us that the cylinder is not firing as it is supposed too. This means the...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...