The reason why car engine sputtering when starting and is most obvious is when you are out of gas. With that said, the first thing to check is if your out of gas or not, of course, the car needs gas to run. If the car is out of gas, it will not run.
So, Are you out of gas?
What to do?
Walk to the nearest gas station, fill up a gas can with gas and pour the gas in your tank. Use a funnel if your gas can do not have a spout.
If you are not out of gas, you can rule out the "out of gas" thing. Now, if the starting happens only on wet condition, then the problem is moisture in the distributor cap
As indicated above, the starting problem you are having only occurs in wet conditions. This is a telltale sign of moisture on the inside of the distributor cap. The moisture is simply condensation which results from the high humidity of the air. This seriously interferes with the ignition system's ability to operate properly, causing this vehicle not to start.
What to do?
To immediately correct the problem, remove the distributor cap and dry it with a clean rag. Otherwise, you may want to just wait until, hopefully, the moisture drys. In the future, try to park this vehicle in a garage when you anticipate rain.
However, if this starting happens not only in wet conditions. Here's what you do.
Open the hood of this vehicle and locate the timing belt. You may want to refer to this vehicle's manual if you are not sure where to find it. Often, timing belts are behind a plastic case called a timing belt cover which can be easily removed.
If the timing belt missing or damaged in any way, then there is a problem with the timing belt. The timing belt is extremely crucial in the operation of any vehicle. The slightest problem with it will cause an engine not to start or at least run very roughly.
What to do?
Replace the timing belt. If you want to do it yourself, refer to an appropriate manual for instructions. Beware that this is a very big job. Otherwise, have this vehicle towed to a garage and have the work done there. Make sure you get a firm price quote over the phone before you have this vehicle towed.
Now, if the timing belt is not missing or damaged in any way, this is what you do.
Pull off one of the spark plug wires and carefully lay it close to the ground (any clean, grease-free, the metal surface will work). Have a friend crank the engine for a second by turning the ignition key.
As the engine is cranking, look for a spark that should jump from the end of the spark plug wire to the ground. Do this same procedure for all of the spark plug wires but make sure you put the last wire you tested back onto the spark plug before you goto the next one.
If you see a spark jump to the ground for all the spark plug wires tested, then there is a possible problem with electronic ignition. We could not establish a likely cause of the particular starting problem you're experiencing. However, the problem could be that this engine's electronic ignition system is not operating normally. Although these systems are generally very reliable, they are still known to have problems.
What to do?
Check to see if this vehicle is under warranty. If so, you're in luck. If not, unfortunately, you have no choice but to either has this vehicle towed to a garage or to have a mobile mechanic come to the vehicle.
If you did not see a spark jump to the ground for all the spark plug wires tested, then it is a bad coil. This car isn't starting and it sputters while you're trying to start it. This could be a serious ignition problem. We asked you to do a test involving each of the spark plug wires. As indicated above that with at least if one of them, you didn't notice a spark jump to the ground as the engine was cranking. This means that either the spark plug wire is bad or the coil is not providing enough current to the spark plug wire (which would then, of course, indicate that the coil is bad). We tend to favor the coil being the culprit in this situation simply because coils tend to go bad before spark plug wires.
What to do?
Remove and replace the coil. Is this vehicle under warranty? If no, get it to a garage or have a mobile mechanic come out to wherever the vehicle is stranded.