Acceleration Issue V8

[BigMike18]

When I accelerate after a stop sign or red light there is this hesitation in my 05 4runner that feels like the car is almost charging up and then boosts forward. It not an instantaneous forward motion it kinda lacks "power" I guess and I have the Kit for the SAIS failure, but I'm not sure if those block off plates got installed(the previous owner installed them). I just replaced the tailpipe and one of the rear cats.

Added, my buddy's car does the same thing he has a very beaten up grand Cherokee and he has it way worse than me its horrendous on there, feels like a manual. But he hasn't replaced any exhaust parts. My thought here is its a clogged rear left cat? or something to do with the SAIS plates, but if anyone is inclined in this area I would greatly appreciate it, thanks.

 

[importman]

When I accelerate after a stop sign or red light there is this hesitation in my 05 4runner that feels like the car is almost charging up and then boosts forward. It not an instantaneous forward motion it kinda lacks "power" I guess and I have the Kit for the SAIS failure, but I'm not sure if those block off plates got installed(the previous owner installed them). I just replaced the tailpipe and one of the rear cats.

Added, my buddy's car does the same thing he has a very beaten up grand Cherokee and he has it way worse than me its horrendous on there, feels like a manual. But he hasn't replaced any exhaust parts. My thought here is its a clogged rear left cat? or something to do with the SAIS plates, but if anyone is inclined in this area I would greatly appreciate it, thanks.

I kinda doubt it's a clogged cat. The symptom would be different. I'd look more at the mass air flow meter or fuel system. First thing I'd do is clean the MAF and see if it helps.

 

[lord rigatoni]

i agree with importman, try cleaning the MAF sensor. a dirty MAF sensor can jack up your air/fuel mixture and cause hesitation, misfire, rough idle, basically not what you want. if that doesn’t solve the hesitation issue, i would pull the injectors and clean them out since they get dirty over time and start having a weaker or more inaccurate spray. good luck!

 

[BigMike18]

I’ve checked the fuel pressure and it was perfect around 42 and I just got a new Toyota oem Maf so I know it’s not those two. I’ve got new spark plugs, intake manifold gasket and no vacuum leak.

 

[Tironeous]

Possible seized brake caliper?

 

[BigMike18]

Possible seized brake caliper?

Nah this is definitely a combustion or engine issue the way it feels in the Petal. And I’ve done my brakes and looked at them even replaced one beforehand.

ADDITION- forgot to include when I start the car no matter the temp or time since last start the rpms are high and continue to stay high every time I’m in park around 1500-2000 fan speed goes nuts

 

[TheV6ThatCould]

Common things being common with the 4th Gen, it might worth greasing all the zerks on the driveshaft. Sounds suspiciously like driveshaft clunk.

 

[triethylborane]

Have you used a reader to see if there are any pending codes?

Checked fuel trims? Even with a new MAF, there is a slim chance it is faulty and the ECU is defaulting to base maps. I dont know about how Toyota programmed the ECU, but if you pull the MAF, the default map will usually run rich trims.

Smoke test for vacuum system issue?

This sounds like a misfire in some respects. Though, my guess is you know what that feels like behind the wheel. It would also likely be tripping the CEL.

Could be a coolant temp sensor given the high idle . . .

Bottom line is you need to get the sensor data from the ECU.

 

[08TxRunner]

Check for proper VVT solenoid operation and clogged screens.

 

[Duckman1]

My 08 V8 was hesitating too. I cleaned the throttle body and MAF and it fixed mine.

 

[sundance21]

Yep. My bet is the throttle body. They get dirty rather quickly and they are so easy to clean. Just pull the hose off and spray a little. Wipe if you have to. Make sure to use the right cleaner made for throttle bodies ... do not use carb cleaner. You issue is coming off idle, which is directly related to the throttle body passages.

 

[noahmas]

Nah this is definitely a combustion or engine issue the way it feels in the Petal. And I’ve done my brakes and looked at them even replaced one beforehand.

ADDITION- forgot to include when I start the car no matter the temp or time since last start the rpms are high and continue to stay high every time I’m in park around 1500-2000 fan speed goes nuts

did you ever resolve this issue?

 

[BigMike18]

I believe I just replaced the fuel injector grommets (causing unwanted air to go into system), and started waiting until rpms drop below 1000 on start ups EVERY single time I drive it. I believe it helps get rid of the jolt, but it does not completely go away just is not as significant.