Enging Surging While Crusing, Fuel Trim Reading High... (1 Viewer)

[generalli]

Has anyone had a surging problem with their Sequoia, or anything with the 4.7, before? Problem started happening about a month ago. Every time the car gets to 2000-2500 rpms, the engine starts surging and stumbling. No codes are shown however when I plugged my scanner in, the long term fuel trim readings are 14.5% for bank 1 and 21.7% for bank 2. When the car is actively surging, the short term fuel trim jumps from -10-15% to around 5%.

So far to remedy the problem I have done:
- Cleaning MAF sensor
- Cleaning throttle body
- Replacing air filter.

What should I do now to diagnose the problem?

 

[gnob]

it's going way lean.
i would personally start with plugs and fuel filter going from this tiny bit of info

 

[generalli]

it's going way lean.
i would personally start with plugs and fuel filter going from this tiny bit of info

Could it also be the fuel injectors or fuel pump? I'm also getting a strong smell of gasoline when I start up the car in the morning.
The spark plugs are replaced about 30k miles ago with iridiums, and the 05-07 Sequoias doesn't come with in line fuel filters, it's in one with the pump.

 

[gnob]

Could it also be the fuel injectors or fuel pump? I'm also getting a strong smell of gasoline when I start up the car in the morning.
The spark plugs are replaced about 30k miles ago with iridiums, and the 05-07 Sequoias doesn't come with in line fuel filters, it's in one with the pump.

does it continue to surge past that rpm?
what happens when you go heavy load or WOT.
do you get heavy miss if you attempt to power brake it?
vehicle with a miss is going to load up the cats.
both banks with similar high trim is generally going to point towards initial fuel delivery like the pump or filter.
injector or plug will show more typically one bank.
could still be afm related as well. what's that data look like and are you using a k&n filter?

 

[generalli]

does it continue to surge past that rpm?
what happens when you go heavy load or WOT.
do you get heavy miss if you attempt to power brake it?
vehicle with a miss is going to load up the cats.
both banks with similar high trim is generally going to point towards initial fuel delivery like the pump or filter.
injector or plug will show more typically one bank.
could still be afm related as well. what's that data look like and are you using a k&n filter?

It only surges from 2000-2500 rpms, and only under medium acceleration, for example going up hills or accelerating from 60-70 mph. OEM air filter and I've never tried to power brake it.

Wouldn't a misfire show up with a code usually? The only code I've gotten is an intermittent knocking code that shows up about once per 500-1000 miles.

 

[generalli]

It only surges from 2000-2500 rpms, and only under medium acceleration, for example going up hills or accelerating from 60-70 mph. OEM air filter and I've never tried to power brake it.

Wouldn't a misfire show up with a code usually? The only code I've gotten is an intermittent knocking code that shows up about once per 500-1000 miles. Goes away after restarting the car a few times.

 

[gnob]

unfortunately not always.
ive dealt with several vehicles with an obvious miss that wouldn't blow code.

the uphill and 60-70 thing points to a miss for me.
try to powerbrake or drive it a little harder and see if you can force it.
or get with someone that has a reader that shows misfire counter per cylinder