Intermittent Hiccup when engine running

My Car 2002 Buick Le sabre Limited has a intermittent stall problem. It happens wether I am at a stop or driving at any speed. It kind of hiccups for about 1/4 of a second. Sometimes it does it two or three times in a row by 1 or 2 seconds between each hiccup. The engine runs smoothly 98% of the time.
I have no clue what is wrong. I talked to a local garage mechanic and he said that the intermittent problems are hard to find. It does not produce a fault code. No service engine light.

Anyone have any ideas? THANKS!

First suspect is water in the gas. If you live where temperatures fluctuate and humidity changes, you can get moisture condensation on the inside of the gas tank. I’ve seen this when a car is kept in a heated garage then driven on a cold day. When this water mixes with the fuel, little drops of it get in the fuel line, and when one hits an injector, a misfire occurs. The fix is to add a gas dryer product, made with isopropyl alcohol, to the tank. This combines with the water to break it up into such tiny droplets that it doesn’t affect the combustion process. The isopropyl also cleans the injectors, in case the problem is a sticky injector.

1 Like

You just answered a 5 year old post. I hope the op found the problem by now.