Stalling and stuttering

[thedeadtext]

So I am stalling at idle and it falls flat at certain points of accelerating, particularly when just slightly accelerating - just falls flat, gargles and sometimes stalls.

It stalls continually in heavy traffic. Runtime seems to have something to do with this as the first 15-20 minutes of the day, no issues.

Putting your foot into it sometimes helps. When heavily accelerating, you can hear it surging or something - running normal for 2 seconds, then falling back 2 seconds, then normal, then back... It is not perceptible in the motion of the car, but you can hear the engine doing this.

At slow speeds, this same activity stalls it.

I previously had a plugged cat converter that I just swapped. I have replaced the spark plugs about 8k mile ago.

The only engine codes I have seen was one for misfire in number 6 (ordered coil/wire set just as precaution.)

It seems computer related due to its predictable weirdness of 2 second good/bad behavior. Or? Throttle body? Fuel rails? Injector? Just not relearned since plugged converter?

[DirtyBacon04]

sounds like fuel delivery issues. starting with the easy basics, clean throttle body, MAF sensor, maybe run some lucas fuel injector cleaner. Perhaps some seafoam. Whens the last time you changed fuel filter? Has this happened through several tanks of gas?

[thedeadtext]

This is the fourth tank of gas where it has been happening.

That said, maybe accumulated water? We have a lot of dew point condensation (right on the ocean + Oregon weather) even in the summer.

I will grab some lucas and seafoam tomorrow. I planned on starting with the throttle body tomorrow - hadn't thought of the MAF - will do that at same time - thanks!

My only thought on the throttle body is how inconsistent it is and how perfectly timed the surging is (ie. seems electronic not mechanical). Is there a way to test the electronic elements of the throttle body?

[DirtyBacon04]

I'm sure there is and I'd summon The Roadie to answer a question like that.

[Anthony Hernandez]

A word of advice, Lucas is junk. All of their products are chlorine based. Never a good thing for any vehicle. And they always go get amsoil for thier own stuff. Seriously. Spend the extra pennies and use amsoil products.

[Trail X]

I'm guessing the 2 second interval is due to the engine overreacting to a bad sensor, adjusting, and then overreacting again in the opposite direction. Could easily be something like an o2 sensor, intake pressure sensor, or throttle position sensor. No particularly fantastic way to tell without it totally failing. You could try running it with certain sensors unplugged one at a time to see if it changes the idle quality. Start with a good cleaning though and systematically eliminate the obvious things.

[thedeadtext]

Cleaned the throttle body and the MAF. Started, ran 10, off 10. Repeated two more times.

Then went for a hard drive.

No stutters.

So thanks for the right road - I am guessing the MAF was totally plugged or giving crazy indications. The throttle body wasn't that bad.

But for fun, at the top of Mt. Hebo, it popped a P0480.

Relay and sensor first. Then a million other sensors.

Then clutch