Re: miss-fires especially when cold, hesitates when you...
I had this happen recently to our Buick rendezvous. Unfortunately it was due to a blown head gasket. It goes away when warm due to the block expanding. Coolant was getting through into the cylinder. Hopefully this isn't your problem but the same symptoms. We had replaced plugs, wires, and an 02 sensor before comfirming it was a head gasket. Luckily ours was covered under warranty.
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
A P0301 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #1.
Symptoms may include: * the engine may be harder to start * the engine may stumble / stumble, and/or hesitate * other symptoms may also be present
Causes: A code P0301 may mean that one or more of the following has happened: * Faulty spark plug or wire * Faulty coil (pack) * Faulty oxygen sensor(s) * Faulty fuel injector * Burned exhaust valve * Faulty catalytic converter(s) * Running out of fuel * Poor compression * Defective computer
Possible Solutions: * If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back. * If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
Check you're catalytic converter, Dont know how fast 40-60 KPH is but if it is near 40 miles per hour and has no power up hill that would be the first thing I would check. second would be Fuel pump... Hope this helps
If this is the 3.0L engine then I would start by looking at basic tune up items such as spark plugs, plug wires, coils, etc., especially if it has 100k or more on it. Don't forget to check or change air and fuel filters as they can cause performance problems also. The spark plugs in these were usually good for about 100k miles but some would wear out sooner, depending on severity of use. If the "check engine" lamp is on, and it most likely is if it runs this poorly, then you should have a service code or two that would help diagnose the problem. There are a lot of other things that can cause it to run like this but it's always best to start with the basics to make sure they are good and work outwards from there.
I would also change the igntition coil if you have not done that already. Have you changed the fuel filter? I would change the fuel filter, if you have a clogged filter thenit may run good at idle and less load conditions but when you call for more fuel during hard excelleration or at highway speeds the engine will not get enough and it will lean fire and buck and miss.
Actually there are two kinds of engine hesitation.One is from fuel then two is the air .The mechanic should check on the fuel filter .look if the fuel that is going to the fuel pump is dirty or worn out . check the fuel filter then look if it is dirty and needed to be replace or change.Then the second is that the air filter it should also be check if dirty then replace it so that no dirt will go to the engine . if these problems are not solved then the cylinder will be having a problem that will cause the engine to hesitate.And always check the fuel you use to place to the fuel thank if dirty or diluted just to be sure.
Just a few things to check. Take off the fuel filter and make sure there is no water in it. If you have put in different spark plugs than AC Delco, then change them to AC Delco. If you haven't looked at the plugs or the fuel filter, then it is way past time to replace the filter and new AC Delco spark plugs only. These places that insist that you use Bosch plugs or split fire plugs don't know ****. The Delco plugs are made especially for your engine and will out last those cheap non-working Bosch plugs.
If the fuel filter and plugs don't fix it, make sure your air filter intake isn't stopped up with a bird's nest. Happens a lot. If it still misses after new plugs, you may have a fuel injector sticking.
The bad smoke is the gas-thinned oil passing the rings and unburnt fuel smoke. The missing really bad is most likely fuel soaked spark plugs. Make sure you change the oil while changing the plugs or you will have a redo. Let us know if any of this helps. Dale