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Sluggish acceleration IS300


Jack_Frost
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Hi everyone,

I’ve been lurking here a while but first time posting. After some help please.

So, as the title suggests, my IS seems to be suffering from very sluggish acceleration. Up to around 2500rpm the engine revs happily but I don’t get very much response at the wheels. It feels like a manual with a slipping clutch. Definitely more pronounced than normal torque converter lag. I’ve check the trans fluid level, which seems fine.

I’ve read lots of other threads about poor response pointing to MAF sensor, throttle body, TPS, ECU reset etc. But as the engine itself seems to respond well it’s leaving me wondering whether it could be any of these or not.

Any ideas?

Thanks!

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Worth disconnecting the Battery overnight, this should clear any "stored" faults in cpu. Also worth plugging in an OBD code reader, might show something like a faulty Lambda sensor which can bugger things up. Has the engine warning light come on?

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And cleaning the element to the MAF is a doddle so you can exclude that easily enough. I did mine the other week. It was black. Can't say it made any real difference but worth doing I reckon.

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Like Richard says, cleaning the MAF is a doddle, two screws and a can of contact cleaner and that's it. Easy enough as well to take off the air intake tract and have a look at the butterfly to check cleanliness and free movement (remember the ignition will need to be on if you want to check the latter). I checked my for the first time a few weeks ago and it was - reassuringly - clean as a whistle. Perhaps invest in a couple of tanks of V-Power if you don't already. Check for air leaks in the intake tract, sloppy clips or splits. After that, you might be looking at plugs, etc.

If it's actually a gearbox issue (which sounds like what you're describing), then as Chris suggest disconnect the Battery and let it reset and relearn your driving technique. You say the transmission fluid is at level, but do you know how old it is? What sort of colour is it? 

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Unlikely to be the MAF unless your experiencing erratic idle. could be something daft like a dirty air filter or even the plugs.

I reckon a full service would put it right 

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