I have a 2008 Tc that has about 55,000 miles on it, as of about last week a started to notice a significant delay in acceleration once the vehicle had warmed up. A few days ago I noticed that the engine was idling fairly low around 600-700 rpm, when i rev the engine it doesn't want to go past 2000 rpm and sounds pretty horrible. If i drive it for extended periods of time and stop it has little to no acceleration at all and idles pretty rough, then it kicks in an accelerates quickly. I really need help figuring this out, if you could give me some advise i would appreciate that.

 

Clean ur MAF sensor.

Check ur plugs/replace if needed.

Check ur air filter/replace if needed

Enjoy ur car.

 

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OR
did you disconnect your battery causing the ecu to reset?

 

any cel? if so could be a cat needing replaced

 

Everything that was said previously is a good place to start. I would also suggest testing the throttle position sensor if you have the means. If it has a CEL on, get the code checked and post it up here. That makes a world of difference in trying to diagnose the problem. Beyond that, it'll probably have to be hooked up to an engine diagnostic computer to see what's gone funky. I can think of half-a-dozen different things that might cause the problems you're describing - ignition coil, O2 sensor, MAF, etc... The only way to know for sure is to have it checked out. If you take it to a shop, make sure they have an engine diagnostic computer with the software for your car! It being a fairly new model, a lot of shops wont have the correct module for it - make sure they do before they check it out. Otherwise you may be paying them $60 an hour just to guess.

~Laken

 

The problem could be the throttle body is dirty and needs to be cleaned, especially after the battery is disconnected, the ecu constantly learns where idle is and adjusts as needed. even when it gets dirty, when u take away power and its leaned values it can not idle or accelerate properly. or you could have and air leak after the maf, in which case you need to spray brake or carb cleaner around the vacuum lines while the engine is running to find it. the third case is if you have the purge line and charcoal canister fresh air lines backwards. the last one Ive accutally seen lots of I hope that helps, good luck

 

I cleaned the MAF sensor yesterday to no avail, i am going to check the spark plugs and air filter sometime today. I noticed something else today, when im in park I can rev the motor up to 3-4k rpm but when im in drive and i rev it seems really bogged down and wont make it past 2k rpm.

 

Sounds like a restricted exhaust. Perhaps the cat is clogged. Also check for vacuum lines. Could also be a restricted fuel filter (which is part of the sending unit) A lack of fuel volume would cause hesitation under load. How is the air filter?

 

So it sounds like the problem is most noticebale when the engine is under load, but you also have a slightly rough idle. More details are always helpful!

This actually sounds exactly like a problem that was very common with the old Nissan VG30 motors. One half of one of the ignition coils would go bad, but the ignition signal would look normal at idle, though a little rough. When you stepped on the gas the engine would stumble like crazy until you got it up around 3,000 RPM, then it would smooth out and take off.

I think a clogged fuel filter or weak fuel pump are definite possibilities though. I still think it would be worth checking out the throttle as well - either the position sensor, or something in the drive-by-wire system.

I'd imagine if there was a vacuum leak large enough to cause this problem then it would throw a CEL, and with how picky OBDII systems are about emissions equipment, I would expect a clogged cat to cause a CEL too, though it would depend on how well it was still functioning (burning the remaining oxygen in the exhaust).

Wait a second... you don't have a banana stuck in your tailpipe, do you?

 

It was the o2 sensor after all, sorry for the extremely late response

 

which one? and what was wrong with it?