The year, make, model and engine would help us help you.
Spark Plug replacement should be included with every major tune up. As a general rule the OEM plugs on most import cars are good for up to 100 000 kms. The simplest way to check if your plugs need changing is to remove them (one at a time, you should never remove more than one.) Once you take a plug out, check the diode (tip) if its fouled (search 'fouled plug' for images), then it should be replaced. If it is clean, then you reinstall it and move on to the next cylinder. Be sure to keep the proper plug wires on each plug, as mixing these up will screw up your firing order, and make your engine run rough...or not at all. If ANY of the plugs are fouled you should replace ALL of them. They are relatively inexpensive and changing one or two is a bad idea.
two if you miss the lay up, one if you made the lay up
Their are many reasons that are possible. The most common two are tire wear (or inflation) and tune up. You may have fouled plugs or a dirty air cleaner that would be addressed in a tune up. Hybrids are very icky automobiles. You need to keep up with ant required maintenance issues.
possible bad fuel pump, fouled spark plugs, bad fuel injectors, could be many things. most likely chouce is the first two. check those first
It probably needs a tune up. The two main problems that cause this are that either the spark plugs are fouled and need to be replaced, or the bearings in the A/C compressor need to be replaced. Obviously the spark plug option is the least expensive. Isuzu recommends that you use Nippondenso plugs but I've found that Bosch platinum plugs work great.
Two. Like always.
Possibly you're using the wrong grade of gas - timing is out of specifications - the cylinders are becoming carbon fouled - fouled spark plugs. For a simplle fix try this - run a can or two or fuel injector cleaner through your gas tank and see if it imprioves or not. If it doesn't work you've only spent about 3 bucks and THEN you can go on to one of the more expensive options.
Have you checked all of the High Tension leads from the distributor to the plugs, or just one or two? Same with HT lead from Coil to Distributor, Check Distributor cap for cracks
Glow plugs and injectors are two different parts of two different engines. You may be referring to glow plugs or spark plugs. If you have a diesel engine, you will have glow plugs. If it is gasoline, it is spark plugs.
You cannot keep him from leaving you or getting "stolen" if he chooses to leave however, you can only do what you are capable of in the capacity of having a good relationship between the two of you.
Head gasket. Just starting to go and as the motor warms up it expands and seals the gap. Oil is getting into the coolant and since oil floats on water it goes to the overflow. Lack of speed, one or two plugs are fouled or you are loosing enough compression on 1 or 2 cylindars.
Mischief is spelled incorrectly.