Air intake or idle problem in 2002 mazda

mazda
protege5

#1

I bought this vehicle used three years ago, and the same problem has cropped up occasionally the whole time I’ve had it:



when the weather’s wet or humid, when I start it up it chokes up and dies. Or it idles really choppy, slows way way down, and can only recover if I put the clutch in and pump the gas hard again and again. It feels like there’s no air getting to the engine.



I’ve had the mechanic flush the fuel injection twice, once when I bought it (which helped a little) and again last month (which, again, helped a little more). I’ve replaced the air intake hose, which helped significantly. But it’s still doing it.



Where ought I to look next to address this problem? I love this ugly little car so I’d really like to get the thing right.


#2

What happens after initial start up? Does it eventually keep running? Does it then run smoothly?

Any check engine light? If so you need the error codes as a starting point for figuring it out. Large chain auto parts stores will read these for free, and the format is a P w/ 4 numbers (e.g. “P0301”)

How old are your spark plugs, wires & air/fuel filters? The next time the weather is dry (i.e. when this problem doesn’t occur) use a spray bottle to put a fine mist over the plugs, wires, coil/distributor cap. See if this makes the engine stumble or something.

Also mist whatever electrical connectors you can see along the intake tract up to the throttle body - mass airflow (MAF) sensor, air temp, idle air control (IAC) valve…

Cleaning the IAC, MAF & throttle body could help - might not, but it certainly won’t hurt. Its just good maintenance.


#3

That’s very helpful. Thank you.

The car runs great and idles fine once it gets the burps out of its system. It only happens when it starts cold.

No “check engine” message. The plugs are… I don’t remember.

Thanks for the leads!