At times after stopping at a Red Light or Stop0 Sign, the car seems to be (stumbling/hesitating) when I am driving off. I have put "FUEL injector cleaner into the gas tank on several occasions, there is usually a slight improvement, then there problem returns.
My car "stumbles" when I drive after stopping at a red light of stop sign. on 2002 Mazda 626
by Alfred T. Soley in Killeen, TX on June 29, 2011
ANSWER by Superbob on June 29, 2011
There are two things that come to mind. One is that the 2.0L engine is prone to intake manifold vacuum leaks due to a faulty gasket. This is easy to find and fix. To find it, spray a small squirt (fire hazard - use care) of carb cleaner (a fuel) under the intake gasket area and see if it makes the engine run different for a moment. If so, then the gasket is leaking and replacement is fairly simple. This other thing I think of is that the rubber intake duct between the air filter and the throttle body is leaking air due to a loose clamp or a split in the duct. Use your hands to feel around the duct and see if it's loose or torn. Easy to fix. You don't mention that the check engine light is on, so I assume it isn't. If it were, it'd be an important piece of information. Here's something on the Malfunction Indicator Lamp (MIL): The check engine light indicates that the computer has detected a malfunction in the engine/transmission control system and has diagnostic codes and data stored which would be essential in diagnosing the problem. A technician with a scanner can access the diagnostic codes and data and then be able to give you a diagnosis. You'll probably need a tech with a scanner to clear the code responsible for the check engine light, although if the problem is fixed, it may go out by itself after perhaps a long time. If you want to find a Mazda specialist, here's our directory link for you: https://repairpal.com/directory?address=76541&car_brand_names=Mazda