Why does my acceleration fluctuate?

helvetical · 05-11-2008, 03:51 PM

Hello all,

Currently i have about 9K miles of trouble-free driving on my FJ, and it is due to that I have to pick on the littlest of details....

I have noticed that my FJ's acceleration never seems to want to stay constant... sometimes it is like a rocket and feels very confident with little noise and other times it's hesitant and the engine whines. While similar to the performance loss of having the A/C on, this is more noticable.

Thanks and I look forward to any input on this issue.

***neworleansparrothead*** · 05-11-2008, 04:27 PM

Quote:

helvetical previously said:

Hello all,

Currently i have about 9K miles of trouble-free driving on my FJ, and it is due to that I have to pick on the littlest of details....

I have noticed that my FJ's acceleration never seems to want to stay constant... sometimes it is like a rocket and feels very confident with little noise and other times it's hesitant and the engine whines. While similar to the performance loss of having the A/C on, this is more noticable.

Thanks and I look forward to any input on this issue.

Dude, I have no clue. I have 26k on mine and don't experience what you are talking about.

Kim

**BPSFJ** · 05-11-2008, 04:47 PM

Quote:

helvetical previously said:

Hello all,

Currently i have about 9K miles of trouble-free driving on my FJ, and it is due to that I have to pick on the littlest of details....

I have noticed that my FJ's acceleration never seems to want to stay constant... sometimes it is like a rocket and feels very confident with little noise and other times it's hesitant and the engine whines. While similar to the performance loss of having the A/C on, this is more noticable.

Thanks and I look forward to any input on this issue.

I know with diesel engines weather has a lot to do with it. The colder the air the more power and the warmer the are the less power. I would think the same thing goes for gas engines.

**CowboyCEO** · 05-11-2008, 10:16 PM

Maybe your a/c is on....................Check your air filter........just a thought......

DoWork · 05-11-2008, 10:20 PM

air filter, fuel type, weather conditions, amount of weight. All things that can affect your acceleration.

**DEWFPO** · 05-12-2008, 02:57 PM

Welcome, helvetical,

My AT FJ is pretty darn consistent. I did notice a little change when I put a fresh air filter in at ~17,500 miles. The engine didn't seem to labor as much on the same drives as before. But mine always has about the same amount of get up and go. I try to use the same gas stations and only use premium.

DEWFPO

Fjamming · 05-12-2008, 03:04 PM

Nothing erratic experienced on my FJ. Ambient temperature, load, gas used, condition of air filter, tire pressure, and maybe a ton of other things should be considered. Did you time it or was it just perception?

mobius012 · 05-12-2008, 04:51 PM

FJ's use a standard clutch cooling fan not an electric............. as the temp changes the fan has to adjust and kick on full force more often, robbing you of horsepower ......... I live in Phoenix , Az, AKA hotter than hell ....... the performance is literally night and day thru night and day ....... some people may not notice all that much , but the way I drive , their is no mistaking it .......

**RoverGGM** · 05-12-2008, 05:41 PM

Why does my acceleration fluctuate?

Just a guess, but you're accelerating and comparing your acceleration with the transmission in different drive gears.

If you moderately accelerate, the vehicle will shift up to a higher gear quicker, making the acceleration seem sluggish compared to the lower gear's performance.

**stringmachine** · 05-12-2008, 05:50 PM

so have you been switching between fuel octanes? if so you might also try to disconnect the negative battery terminal and leave it for 5 minutes then reconnect and try it again, remember you will have to reset your sealtbelt chimes off setting and your radio settings.. my 02
also check your air filter, air cleaner elemnt make sure it is secure and fastened..