93 Ls400 Acceleration Problem

[LennyK]

I seem to have this really odd problem with my LS400. While accelerating at the speed of between 40-60 mile range, the car consistently hesitates, hestation turns into forward shaking. It always goes away when the speed reaches 60, and does not start again untill you get back to 40MPH again.

Anyone has any ideas as to what the issue may be. Thanks in advance

[supacop242]

I have the same problem with my 1992 LS 400. Let me know if you find the answer.

[silvermate]

is the engine stumbling or cutting out?,

meaning does it do it only when you are on the gas at 40mph or does it do it when you are off the gas as well (coasting)

or is the car shaking all together when that speed is reached? (non engine related)

if it shakes when the car reaches that speed on any occasion these are the things to check for..

Wheel balancing

Alignment

Tire condition

Suspension condition (ie...ball joints, struts, ect....)

[VBdenny]

The throttle body is clogging up. Clean it up using O'Bergs tutorial. I have it on file.

[lexs400]

do you ever feel a shudder when the gears shift around 40mph or so ? It could be related to torque converter as well.

The throttle body is clogging up.  Clean it up using O'Bergs tutorial.  I have it on file.

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[ThunderRiver]

It is possible that your air-flow control censor is dying. Make sure you have it checked as it can be dangerous on the road.

[LennyK]

Thanks for the reply,

The hesitation stops as soon as I let of the gas, or if I floor it to reach that 60mph speed. The car seem to idle fine, no known vibration that i can tell, related to tires.

thanks

-L

is the engine stumbling or cutting out?,

meaning does it do it only when you are on the gas at 40mph or does it do it when you are off the gas as well (coasting)

or is the car shaking all together when that speed is reached? (non engine related)

if it shakes  when the car reaches that speed on any occasion  these are the things to check for..

Wheel balancing

Alignment

Tire condition

Suspension condition (ie...ball joints, struts, ect....)

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[duckfat]

I seem to have this really odd problem with my LS400. While accelerating at the speed of between 40-60 mile range, the car consistently hesitates, hestation turns into forward shaking. It always goes away when the speed reaches 60, and does not start again untill you get back to 40MPH again.

Anyone has any ideas as to what the issue may be. Thanks in advance

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I have a 93 LS400 and I have the exact problem you discussed. I tried changing to a different gas but it didn't help. It seems to be related to the RPM (little over 2000), however, when I rev the engine to 2000 in neutral, it's perfect - no hesitation.

[nc211]

Lenny, did you ever figure out what the problem was? I've got a 95 with new motor & tranny mounts, it does the exact same thing.