Engine Hesitation/ Stumble

A

ADVnut

New member
Looking for some opinions here.

My 2014 4Runner has roughly 103K miles on it.

At about 100K I started having an issue with hesitation. No, this is not the normal drive by wire hesitation. This happens sometimes when accelerating out of a turn. It happens at highway speed with a slight rumble feel before it hesitates.

Around 2-3K miles ago I cleaned the MAF and throttle intake. Neither were terribly dirty, but there was a bit of gunk on the intake. The problem seemed to go away, but it is back now worse than before.

No codes are being thrown.

I was going to wait until 120K for the spark plugs, but will change if it might help.

What about the TPS?

Any other ideas? I searched the forum, but may have missed something.

Any advice is much appreciated as it is driving me nuts.

Edit: What started out as hesitation while driving, has developed into stalling/ not starting later in the thread.

:cheers:
 
Last edited:
Register to hide this ad
1engineer said:
Did you change the place you buy gasoline in the last 3K miles?
Click to expand...

Haha. My first thought was bad gas. I have filled up many places all over the Southeast and it persists. Even ran a bottle or two of Redline Fuel cleaner for the heck of it.

Hoping its not a fuel filter.

Thanks!
 
ADVnut said:
Around 2-3K miles ago I cleaned the MAF and throttle intake. Neither were terribly dirty, but there was a bit of gunk on the intake. The problem seemed to go away, but it is back now worse than before.

No codes are being thrown.
Click to expand...

I had an issue with the MAF/TB at 92k, entire engine would just shut off so it's likely you can count that out. I got plenty of codes from it too. If needed I can go back to my messages to another member for the codes.
 
tristero said:
I had an issue with the MAF/TB at 92k, entire engine would just shut off so it's likely you can count that out. I got plenty of codes from it too. If needed I can go back to my messages to another member for the codes.
Click to expand...

Good to know. A few times I thought it was going to shut off. It idles fine. It behaves at slow speeds. Sometimes I press the pedal coming out of a turn and it chugs.

If I give it more gas, it lags then accelerates due to me mashing the pedal.

It's not consistent through.

Codes wold be nice, but non given. Thanks!
 
How do you know there are no codes...? Have you scanned it with TIS yet. If not... there is no way to know. Many things in a Toyota will not set a CEL.



Things I would try:
Scan first...
Clean MAF
Pull the TB and plastic intake manifold. Clean it all real good
Change plugs.

If none of that works you will need to do some data logging to isolate the issue. I can help with that some if you have software....
 
Last edited:
ADVnut said:
Good to know. A few times I thought it was going to shut off. It idles fine. It behaves at slow speeds. Sometimes I press the pedal coming out of a turn and it chugs.

If I give it more gas, it lags then accelerates due to me mashing the pedal.

It's not consistent through.

Codes wold be nice, but non given. Thanks!
Click to expand...

Only when coming out of turns? If this were 40 years ago and you had a carburetor, I would suggest checking the float level.

Odd behavior in an EFI engine, though. Is it at a particular RPM every time, or does it happen at different RPMs? Same gear every time, or different gears? Does it still happen if you use S mode and manually shift to a lower gear? Try to isolate the conditions under which it occurs.
 
Dirty MAF sensor?

I have an Audi A4 that would do that, no codes, tech hooked VAGCOM up to it and drove it around, said all trim levels looked fine. I took it home and it was still doing it. I cleaned the MAF and problem went away. Not sure what this truck's MAF is like, but it's worth the $7 can of MAF cleaner to try. Just be careful and follow directions on the can.
 
Sounds to me like the VSC kicking in to prevent a skid? Try doing donuts in a slick parking lot full of snow, see if the behavior is the same.
 
Thanks for all the replies.

Well yesterday it got a lot worse. It stalled a few times while slow speed driving in parking lots.

Finally limped it home. Disconnected the battery overnight and charged up the battery due to excessive cranking. It will start and idle fine but cuts out when trying to back out of the drive way.

Still no CEL.

Not sure where to go from here, other than the dealer. Which I would prefer to avoid.

I have TIS software and cable, but not super savvy in its use.

Sent from my Pixel 2 using Tapatalk
 
with no codes I doubt any sensor airfuel management component issue..

these do not have a fuel test port as most ALL other vehicles have . my guess fuel tank issue pump/screen/wiring / pump relay ..

I don't know how to test fuel pressure on a toyota PITA..but I did and do on other vehicles same issues low pressure.
 
ADVnut said:
Thanks for all the replies.

It will start and idle fine but cuts out when trying to back out of the drive way.

Sent from my Pixel 2 using Tapatalk
Click to expand...

Does the engine respond to the gas pedal normally when the truck is out of gear and just sitting in the driveway? Does it increase revs normally if you jab the gas sharply? Will the engine maintain a constant 3,000 RPM without faltering?

Again, isolate the conditions under which the problem occurs.
 
TEujunga said:
Does the engine respond to the gas pedal normally when the truck is out of gear and just sitting in the driveway? Does it increase revs normally if you jab the gas sharply? Will the engine maintain a constant 3,000 RPM without faltering?

Again, isolate the conditions under which the problem occurs.
Click to expand...

Seems to behave when out of gear. Engine starts and runs normally. Will maintain 3000RPM. Does what it's suppose to do when I jab the gas. Sometimes it stalls when backing out. Sometimes I can back out and it will stall when it begins to move forward. A few times I have been able to drive some distance. Once it stalls its difficult to start or will not start at all. I come back later and it starts up just fine.

Thanks!
 
Last edited:
ADVnut said:
Seems to behave when out of gear. Engine starts and runs normally. Will maintain 3000RPM. Does what it's suppose to do when I jab the gas. Sometimes it stalls when backing out. Sometimes I can back out and it will stall when it begins to move forward. A few times I have been able to drive some distance. Once it stalls its difficult to start or will not start at all. I come back later and it starts up just fine.

Thanks!
Click to expand...

That's useful information, as it would seem to rule out certain causes. Probably NOT related to the MAF or TPS, as even in neutral the engine would stumble and stall or run roughly when you tried to rev it.

Also seems unlikely to be an electronic malfunction, as you'd get a CEI. The computer thinks everything is just fine, even though it obviously isn't.

I agree with a previous poster who suggested looking at fuel pump / relay / pickup / filter. Could be something intermittently blocking the pickup, or an intermittent wiring short that occurs only when the vehicle is in motion.

Let us know how things turn out!
 
I would still hook up to TIS and see if there are any codes, there may be pending codes which won't set a CEL. I would also see if you can see what the torque converter lockup solenoid, and torque converter is doing. I had a vehicle years ago that was acting similar and it turned out the TC was trying to lock randomly.

Also, It almost does sound like there may be bad gas in the tank. Start the vehicle and use a floor jack to raise the vehicle in different positions to see if it affects how it runs.
 
gm350reratliff said:
I would still hook up to TIS and see if there are any codes, there may be pending codes which won't set a CEL. I would also see if you can see what the torque converter lockup solenoid, and torque converter is doing. I had a vehicle years ago that was acting similar and it turned out the TC was trying to lock randomly.

Also, It almost does sound like there may be bad gas in the tank. Start the vehicle and use a floor jack to raise the vehicle in different positions to see if it affects how it runs.
Click to expand...

Unlikely to be random torque converter lockup, as that wouldn't result in the difficult re-start issue he's experiencing.

it could always be a weird esoteric fault in the fiendishly complex engine/trans computers, but still guessing it's fuel-related and relatively simple -- the simplest solution is always the most likely. I like the idea of moving the vehicle around when it's parked and running to see if the problem can be duplicated with the transmission not in gear.
 
Last edited:
You must log in or register to reply here.

Members online

No members online now.
Total: 153 (members: 1, guests: 152)

Forum statistics

Threads
278,306
Messages
3,554,045
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top