Why does my GMC Truck idle rough in the morning?

So the past couple months I’ve noticed my truck has a really rough idle in the mornings when it is cold out, to the point where it has even died before. I just replaced the plugs about 3 months back and it ran fine after, people have told me things like it is the o2 sensors to the cat is plugged up to my fuel filter is bad.

Why does my Car start rough in the morning?

The following morning the car again started rough (as if it were misfiring/running on 3 of 4 cylinders) and this time it took a good minute before smoothing out. However, after the car smoothed out I experienced no issues on the way to work, no sputtering, no loss of power, nothing.

What causes a car to have a hard start?

Thank Kevin. There are many causes of hard starting but illustrative ones are a faulty engine coolant temperature switch (sensor), malfunctioning idle air control (IAC) valve, vacuum and EGR leaks, inadequate fuel delivery or pressure (clogged fuel filter, injectors), and contaminated or old gasoline.

Why does my GMC truck run too lean?

The scanner reads that bank 1 and bank 2 are too lean and some misfires. The running too lean code could be due to the K&N intake I have. A guy told me it may be my fuel pump, but that is a $272 guess that I am not about to make.

What causes a Chevy Silverado to run rough?

If an oxygen sensor goes bad, it can make your Silverado run too lean (or rich). A super lean running engine will often idle rough. Fuel Injectors. The fuel injection systems job is to atomize the fuel into fine mist.

Why is my F150 hard to start, rough idle and stall?

The most common cause of F150 hard to start, rough idle and stalling is a bad canister purge solenoid that is stuck open, so it’s continuing to draw fuel vapor into the engine. The canister purge valve is located directly above the fuel rail on the driver’s side of the engine.

What are the symptoms of car code p0304?

Many times, P0304 occurs when there are worn out spark plugs, spark plug wires, or a faulty ignition coil. What Are the Symptoms of Code P0304?

When do you need to fix a p0304 misfire?

When P0304 occurs, it should be fixed immediately as long term driving with engine misfires could cause consequential damage to your engine. Many times, P0304 occurs when there are worn out spark plugs, spark plug wires, or a faulty ignition coil.

What to do if your car has a p0304 code?

Use FIXD to scan your vehicle to verify P0304 is the only code present. If other codes are present, they must be addressed first. Check for loose connectors at the ignition coils or for damaged wiring (specifically cylinder 4). Look for loose engine ground wires as well. These can cause random misfire conditions. Tighten or connect where necessary.

What is the code for high engine idle?

The mechanic said that the code from the Check engine light was p1506, or high engine idle. His notes said that the engine idles at 1000+ rpm for more than 1.5 minutes. He ran some cleaner through the IAC and reset the code and told me to inform him if it returned.

Why does my car have a rough start up?

The excess oil gets burnt and is emitted as blue smoke. This is a mechanical problem because engine oil should not be getting into places where it can be burned. In this case, the engine will usually experience a rough start-up, with the idle smoothing out after about 30 seconds.

What causes a diesel engine to have rough idling?

As diesel engines age, the fuel injection system can start to “gum up”, and the injector tips begin squirting instead of misting. The injection timing can get out of whack. Wear and tear on the piston rings and cylinder walls result in lost combustion. Is the smoke coming out of the exhaust pipe blue?

When is engine is cold it studders and misses but when warm?

When engine is cold it studders and misses but when warm When the engine is cold it studders and misses but when warm it runs great and it only happens when I start it and go but if I let it warm up before I go itll run like it should what would cause this issue when the check engine light isnt on and there is no codes on a computer?

Why does my GMC Sierra suddenly stop running?

Truck suddenly stops running, acting like it’s out of fuel. There is fuel in the gas tank and, I can hear the fuel pump when I turn the ignition on. Is there a fuse, or relay that is maybe causing this to happen?

Why does my truck not start after sitting for a long time?

This can happen when the check valve in the fuel pump assembly leaks pressure back into the fuel tank. The longer the truck sits the harder it is to start. Try this, turn the key on for 2 seconds then off, do this two more times then try and start it.

What causes a vacuum leak in a GMC Truck?

When cold a vacuum leak in the intake gaskets allows un-metered air to be registered by O2 sensors and not the MAF sensor. This creates a lean condition and causes pinging in the engine. Once engine warms up the gasket swells and majority if not all of the leak goes away. This PI was superseded to update parts information.

Why does a car run when it’s cold?

While cold, the ring-cylinder mate is tight, keeping the combustion gasses from blowing by and allowing the engine to run.

What should I do if my car misfire after warm up?

Misfire after warm up. Runs great when cold. Has new engine new plugs wires injectors when starts misfiring can shut down start back up and runs fine until a few minutes then starts again. have the same problem? This sounds like you have an intake valve that is leaking. Can you do a leak down test to confirm the issue? This guide can help as well.

What causes a misfire after a warm up?

Misfire After Warm Up: Misfire After Warm Up. Runs Great When Cold… Misfire after warm up. Runs great when cold. Has new engine new plugs wires injectors when starts misfiring can shut down start back up and runs fine until a few minutes then starts again. have the same problem? This sounds like you have an intake valve that is leaking.

Why does my GMC Truck idle rough in the morning?