Hesitation/ Bogging

[jro909]

i've been noticeing that after driving 30-40 miles or so in the heat, i'll hit town and start to go into stop and go traffic..the truck seems to hesitate/kind of bog from a dead stop, i hit the pedal and it will kind of pause then shoot up and 1500rpms give or take and shift like usual...it just dosen't seem smooth like a steady climb up to the shift point, just a hesitation then jumps up and shifts...any ideas? this only only happens after long periods of driving and only in stop and go traffic, the hesitation makes me look like an old man driver....its fine on the highway no problems or rpm hopping like the trans the is slipping or anything

[06MonteSS]

i've been noticeing that after driving 30-40 miles or so in the heat, i'll hit town and start to go into stop and go traffic..the truck seems to hesitate/kind of bog from a dead stop, i hit the pedal and it will kind of pause then shoot up and 1500rpms give or take and shift like usual...it just dosen't seem smooth like a steady climb up to the shift point, just a hesitation then jumps up and shifts...any ideas? this only only happens after long periods of driving and only in stop and go traffic, the hesitation makes me look like an old man driver....its fine on the highway no problems or rpm hopping like the trans the is slipping or anything

 

yeah, your IAT (intake air temp) is probably going through the roof cuz you're sitting in traffic in the heat... so, when your IAT's get above 90*, the ecm starts pulling out timing... the hotter your IAT's get, the more timing it pulls out...

[jro909]

so essentially its trying to make up for the massive heat coming in though the intake? i mean is this normal? thanks for the reply man

[Nytemare]

Yeah...sounds like it is very normal.

[jro909]

drives me nuts lol, i feel like i have to really get on it to keep up with traffic from a dead stop...

[Nytemare]

drives me nuts lol, i feel like i have to really get on it to keep up with traffic from a dead stop...

Sounds like its time for a tune.

[jro909]

why does it do it though? i'm just confused why the truck does that..i mean i have the high cap air filter and the hd trailer package(with the slotted bumper)

[Nytemare]

why does it do it though? i'm just confused why the truck does that..i mean i have the high cap air filter and the hd trailer package(with the slotted bumper)

Its because fuel has different ignition characteristics at different temps.

If you have a higher temp air mixing with your fuel it can combust earlier in the cycle causing pinging. Also hot air is less dense than cold air, ie less oxygen molecules, so it cannot support the same amount of fuel for a perfect stoichiometry...ie A/F mixture. so knowing this the programmers put functions in the ECM to cut fuel and timing as the intake air temp increased. The factory uses a 5X factor of safety for everything though...so you lose a ton more power than you need to.

 

Under the hood heats up like it does, because it just gets hot... Not really much you can do.

You also have an electric fan don't you....Us guys with the clutch fan get a lot less under hood heat because the fan is just about always working.

[jro909]

i think its a clutch fan...its hooked to the water pump i don't drive alot of city so i rarely notice it running but i know it works lol

[Nytemare]

i think its a clutch fan...its hooked to the water pump i don't drive alot of city so i rarely notice it running but i know it works lol

Yeah you have a clutch fan.

 

I don't know man...I don't drive for long periods in city so I have never noticed it do that. But that's the reason is does do it.

[4wd]

i've been noticeing that after driving 30-40 miles or so in the heat, i'll hit town and start to go into stop and go traffic..the truck seems to hesitate/kind of bog from a dead stop, i hit the pedal and it will kind of pause then shoot up and 1500rpms give or take and shift like usual...it just dosen't seem smooth like a steady climb up to the shift point, just a hesitation then jumps up and shifts...any ideas? this only only happens after long periods of driving and only in stop and go traffic, the hesitation makes me look like an old man driver....its fine on the highway no problems or rpm hopping like the trans the is slipping or anything

 

This is exactly what I am experiencing with my 2008 truck, and before with my F-150, in the summer ...And it gets worse as you try to work it harder... Toyota doesn't do that! Why?

 

I am curious about blocking under-hood hot air from getting into the intake, this can be done by insulating the area between the air box and the fender which is insulated by a very cheap stuff, I think this is done to help in the very cold area...Just a thought!!

[jro909]

i'll live with it long as its normal...but yeah its slightly annoying, even worse if the air cons on(i sometimes forget to shut it off once i hit town)

[Nytemare]

i've been noticeing that after driving 30-40 miles or so in the heat, i'll hit town and start to go into stop and go traffic..the truck seems to hesitate/kind of bog from a dead stop, i hit the pedal and it will kind of pause then shoot up and 1500rpms give or take and shift like usual...it just dosen't seem smooth like a steady climb up to the shift point, just a hesitation then jumps up and shifts...any ideas? this only only happens after long periods of driving and only in stop and go traffic, the hesitation makes me look like an old man driver....its fine on the highway no problems or rpm hopping like the trans the is slipping or anything

 

This is exactly what I am experiencing with my 2008 truck, and before with my F-150, in the summer ...And it gets worse as you try to work it harder... Toyota doesn't do that! Why?

I am curious about blocking under-hood hot air from getting into the intake, this can be done by insulating the area between the air box and the fender which is insulated by a very cheap stuff, I think this is done to help in the very cold area...Just a thought!!

 

The throttle "auto corrects" to compensate...all the way to the floor and tucks its self under the floor mat.

 

 

Seriously though, it's just tuned differently in the ECM is all...it may make less of a correction than Chevy