wife's old van
 

OK, you guy have a lot of auto repair or trouble shooting knowledge then me. I banged my head against the wall for a few days now. It started with what weem to be a dead battery. Click, click and click. Just have enough battery to turn the engine over. OK, three year old battery, so off to get new. Upon changing that, went for a test drive only to discovered it running sluggish with no will to rev. Thinking its just something the engine has to cough up then it will clear its throat. Nope, died on wife a couple times on the way to her dad's place. No check engine light, nothing. New cats, and O2 sensor was replaced about a year ago. The van doesn't get used but a couple to three time a week. What do you think? Mass flow sensor? We have fuel and spark.

If the battery hasn't got enough oomph, then it alone could be effecting the other electrical things such as the mass air flow sensor. Earths/grounds?

What sort of old van is it?

06 toyota. Has new battery

Start simple:
Oil.

Battery.
12.4V-12.6V. cold
14.7V ish when running.

If battery is dead from not running, then the gas is probably fouled as well

John,

Its driven 2-3 times weekly. It has brand new battery. I can't seem to think of anything else?

You said it runs sluggish, did that ever get better? Air filter and box reasonably clean? Fuel filter? Plugged exhaust or cat's? Any smoke or backfire?

Gas + Air + Spark(plus timing).
The 3 things needed for ignition to happen.

Check the air filter for mice nests. Take it out and rev up without it. Might be straw in the intake or something stupid.

It won't hold an idle?
MAF would be suspect. Idle Air bypass also. Shoot half a can on the butterfly.
Could be a sticky valve.

Are the brakes dragging? Use an infrared thermometer on them.

Whatever it is is crap from being parked too long.
A little excercize should help.

Will check air filter. I have never had a filter get so dirty that it affected performance that badly. Come to think of it, fuel filter has never been changed.

Mileage?

I like fuel filter, be advised, there is often a specialized gadget for this sort of thing, hose clamp remover for example. There may be a tool for the fuel filter that you should get when you get the filter. It is one of those extra fees you pay, so you don't feel like tearing your hair out in the middle of the project.

Sadly, no such gadget for a starter R&R on a 1970 Olds. Popeye type forearms is what you want for that job

My guess is clogged fuel filter. I had same symptoms years ago with a Toyota on a driving vacation. Changed fuel filter and ran like a champ.

Maybe a “system adaption” after battery replacement.

https://www.mycarspecs.com/replace/toyota/sienna/2006/base/replace-a-car-battery

The gas pedal sends electronic signals to the PCM which then tells the throttle body how far to open

throttle plate opening and closing. In order to open and close properly, the computer must know when the throttle plate is fully closed. Some car makers have a self learning throttle body re-learn procedure. In those 2006 Toyota Sienna s, all you have to do is turn the key to ON and leave it there for 30-secs. without starting the engine. But other car makers have a complicated Hokey-Pokey procedure that requires multiple brake pedal applications, along with several key on/off cycles. Still others require a factory scan tool relearn

There's a good possibility.....

I've found if it's the fuel filter, it's fine if you slowly give it throttle. If you hammer it, the suction pulls all the dirt to the screen and it bogs.

Did you clean the battery terminals?

Both ends of the ground cable should be clean as a whistle.

Ground strap(s) from engine to chassis can break away (rust belt especially). Test with jumper cable connected to engine exposed metal and battery terminal or chassis metal. I often use the strut mount bolts to ground engine to. Not strut main bolt. The peripheral ones.

On the fuel business, I would change the fuel filter and run some sea foam through the gas tank. Your injectors could be somewhat obstructed - however, you should get misfire OBD codes if injectors are clogged.

If all else fails give it an Italian tune-up.
Our CR-V gets used for around town mostly. Took it to San Diego to see the kids the other weekend. Driving at freeway speeds for an hour straight did wonders for it. It's peppier than before and responds to throttle inputs a lot crisper too.
Sometimes all it takes is a good hard drive to get them back into shape.

Drive for a couple minutes while it is acting up and then pull a spark plug, don't let it idle at all. that should give some indication.

I've found critter nests in the air box a couple times with parked cars. They chewed up the firewall and filter which had to be vacuumed out. Put on metal screen and problem solved.

The “system adaption” advice above sounds right. OBD2 drive cycles must all complete to pass smog. They self-tune both the idle speed and fuel curve to get the engine burning clean. Stalling is a symptom after battery change.