Why would snow...

[heRS]

make my Mazda b2600i pickup start missing? Took me a while to figure it out, but when it is snowing and I'm driving my mazda pickup, after about 15 miles the engine starts to sputter under load. I have a 25 mile commute.
It just seems weird, not all snow causes this but a wetter, heavier snow for sure will make this happen. Light snow, no worries. After I shut it off for a while, it starts and runs fine. This pickup usually runs like a clock. It's my winter beater, and delivers me safely in "most" inclement weather.
It's fuel injected, a 90 model 4x4. I thought meybe snow was building up in the air intake, but last time it happened I stopped and checked out the air intake, not a trace of snow.
Any ideas? I'm stumped.

[Scrappy Doo]

Now that is just plain strange.... No idea here.

[heRS]

I know! It's just weird. Runs fine and then starts sputtering, missing, choking out. Park awhile, runs just fine, and it only does it when it snows. It can be raining in sheets and water spraying up off the road, no problem. Get just the right kind of snow and it runs like crap! This is why I'm asking - I know there's a lotta real smart guys here willing to offer advice to a damsel in distress.

[hypurone]

I would check to see that the connections for the intake piping all along the route from the airbox to the MAF to the TB are tight. If the cold causes a split to open or the like, you could have un-metered air entering the system causing a lean condition....

There are some "known" issues as well with those trucks that haunt me from my days as a tech:

1. MAP - pretty obvious it could be affected by the temp/pressure change with that type of weather affecting fueling/timing

2. MAF -- can be affected by the cold and improperly computing air flow

3. ECT sensor -- if not functioning properly can send improper data to ECM messing everything up.

[heRS]

Ok, that makes sense, i'll check for leaks. Thanks for the input.

Originally Posted by hypurone

I would check to see that the connections for the intake piping all along the route from the airbox to the MAF to the TB are tight. If the cold causes a split to open or the like, you could have un-metered air entering the system causing a lean condition....

There are some "known" issues as well with those trucks that haunt me from my days as a tech:

1. MAP - pretty obvious it could be affected by the temp/pressure change with that type of weather affecting fueling/timing

2. MAF -- can be affected by the cold and improperly computing air flow

3. ECT sensor -- if not functioning properly can send improper data to ECM messing everything up.

[8cd03gro]

Are you sure it's not happening when it's cold enough for snow, not just when it's snowing? Try resetting the ECU by disconnecting the battery for a good 20 minutes or so. Try cleaning the MAF sensor. Is the air filter element dirty?