99 runner 3.4 v6 4wd automatic
The truck died while slowing as i was coming off the freeway.
Died while braking ....would not start.
Waited 1.5 hrs and it started and ran perfect.
Driving 200 miles home, it sputtered once while slowing in traffic but recovered
Without incident for the rest of the trip.

So.....always on the decel.....never a sputter while under power or cruising on the hwy.
Runs like a top otherwise. No check engine light.
Where the heck do i begin the investigation?
MAS? Cracked Vacume lines? Gas filter?
Thanks, Kenny S

 

Does it die when brakes are applied or just when letting off accelerator?

 

It would be brakes applied in both instances while off the gas
After it died the first time, i sprayed starter fluid down the throttle body and it started then died again so it appeared to be starved for gas.
Kenny s

 

Sounds like a vacuum leak in the brake booster to me.


Start the truck with the brake pedal pressed and see if the pedal gets softer when it fires up. If it gets softer then it's something else. If the pedal stays firm then you probably have a vacuum leak either in the booster or the vacuum hose going to the booster.

Check the hose with a can of throttle body cleaner. With the engine running just give it a little squirt (don't soak it down or anything) along the hose and especially at the connections. If there's a leak the RPMs will climb and you can find it real quick that way. From what I've heard carb & choke cleaner can hurt fuel injectors so I wouldn't recommend using that.

 

I mostly agree with sparks89 but if its the booster, its likely an internal leak and you wont find it with carb spray. And a leaking booster can still work just fine. Best way to check that is to watch the fuel trim on a scanner while stepping on the brakes. A leak will cause the short term fuel trim to go positive. +20% or higher. Do you hear any hissing sounds when stepping on the brakes?

 

Good point. The throttle body spray is just to check the hose, not the booster itself.

 

Alldatadiy.com has symptom related issues and repairs that may help in your situation.
Good Luck!

 

I'm familiar with what a bad booster feels like but i can honestly say that there were no
Braking issues of any kind that weekend...
I'm fairly sensitive to the runner and the way it runs.......the only other thing i noticed on that trip was that it was munching gas.... Running fine but killing gas
3 guys, gear, AC running.....figured it was pretty normal.

...... But even if it were the booster.....what would make it not start after stalling?
Kenny s

 

Check vacuum hoses and intake hose for a crack/split ends that is sucking in unmetered air on decel.

 

Definitely sounds like a vacuum leak to me.

Has any maintenance been done on it recently? Any changes?

Fink

 

Not vacuum or booster related if it wouldn't restart. Guess I read the first post too quickly. Do you have a scanner to check for pending codes?
Maybe a bad coolant temp sensor? Or a feather stuck to the air flow meter? Fuel pump or contaminated fuel?
You can inspect and clean the air flow meter pretty easily to rule that out.

 

OP, during the 1.5 hour wait in the 1st did you move anything around under the hood? Possibly a wire that has a bad spot and shorts out in strange circumstances? I could see a fuel issue causing the stutter and/or stall, but it seems strange that it would clear itself 1.5 hours later.

 

Funny you should mention the feather because about 15 minutes before we stalled, i drove through a black fog of breeding termites. Clogged my ac condensor solid and my wipers were caked with bugs. They stuck to everything.
We did look to see if any were caked on my amsoil air filter...... But no.
I'll still pull the MAS to make sure both sensors are clean.
Kenny s

 

Oregon, at the gas station we died in front of, i pulled all the fuses and shot starter fluid in the TB to see if it was starved for gas. It started and stumbled and then stalled.
Went for soe grub.....hour later....started and ran fine.

 

If it was Chevy, I'd say fuel pump, however, in 13 years with Toyota, I've only replaced a fuel pump once.

 

I wonder if something got into your brake booster (maybe some of those bugs) and got on the vacuum diaphragm inside and was keeping it from functioning properly.

Check your TPS and make sure that's ok too.

 

COR Or the Maf

 

Thanks for the suggestions!
COR?

Kenny s

 

I had the exact same symptoms in my Volvo S60 and it turned out to be the throttle body needed to be cleaned. Got that done and it's been trouble free ever since.

 

I'm going to start with a fuel filter, mas cleaning, throttle body service and a check of all the
Vacume lines
.............then we just drive it.....!
Kenny s