Skip the auto shop - Our mechanics make house calls

Q: Why is my pickup running rough?

asked by on

Changed plugs, wires, cap, rotor, and coil, also treated fuel tank and changed fuel filter 3 times to eliminate contamination but the vehicle is still running poorly.
My car has a manual transmission.

A: Hey there. You should take a fuel sample in...

Hey there. You should take a fuel sample in a clear glass container, and then if you put the container in a freezer, it will separate the water from the fuel and you will see if you have a lot of water in the fuel.

If there is water present, then you will need to remove the fuel water contamination. If there is no water and gas is not contaminated with anything then you will need to have the engine computer tested for running codes to see if the EGR valve is stuck open causing the rough running engine.

If the EGR is stuck open, it will cause a rough idle to mid throttle but run good at higher RPM's. If the EGR is not stuck, then the fuel injectors would need to be checked for flow causing one or more cylinders to run too lean from previous fuel contamination. If this is the case, then you may need to remove and have the injectors cleaned or replace them with new ones. For a precise diagnosis, consider YourMechanic, as a certified technician can come to your home or office to inspect the rough running problem and follow through with repairs.

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・Save up to 30%

Get a quote

What others are asking

Q: Loss of power while driving and it feels like my car is bogging down - 1994 Chevrolet Camaro

Hello. The issues that you are having can be caused by a number of things. Most of the time, this is caused by a sensor issue. The most common sensor to cause this is the throttle position sensor. When this...

Q: My car is not starting; what should I replace?

Your engine's computer gets crank signals from the crankshaft and camshaft sensors and then uses these signals to fire the coils. To see if the sensors are sending these signals to the computer, you can scan the computer using a...

Q: Truck runs rough with hesitation.

There are many issues that could cause your truck to run rough. If the check engine light is on (which it most likely is) retrieving the diagnostic trouble codes will provide a place to start diagnosis. A certified technician, such...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.