engine stutter
 

I have a 05 tc manuel, when i run it u to around 4k it gets a stutter in it, if i floor it it goes away or wont happen at all. At times its worse than others, ive changed the clutch and that didnt fix the problem. changed spark plugs and maf sensor, im not sure what it realy coud be but am open to any sugestions. Any one else have this problem???? I also have tryed different grades of fuel and that hasnt fixed it at all either. so can any one help.

try cleaning out the throttle body... read up i have a thread for this so maybe your problem could be my problem..

do u have any mods to the car?

yea clean the throttle body, and if you have a intake clean the filter, if not change your air filter. Seafoaming the intake might help also

wow...what the heck made you think changing the clutch would fix this problem? thats alot of work from a very poor mis-diagnosis.

well i thought the clutch becouse the car has 150k on it and its the factory clutch, also i have cleaned the throttle body and the filter. I have a k&n cai, thats pritty much the only mod to the car. I havnt cleaned the intake at all but will seafoam that one tonight.

Sounds like dirty injectors - work ok at full throttle but at part throttle they don't although at light throttle and high revs it is surprising, almost like a fuel map problem.

Yea but i have no idea or the tools to test that. Also the engine dosnt throw up any codes at all

I would say run some injector cleaner in the gas for a while and see if it gets better. I worked on a lawnmower today and it would idle great and run at full throttle but mid-rpm just die. Added some acetone and deep creep to the gas and ran it a while and then let it sit for a couple of hours. After that it ran great. Carb was all messed up from sitting for 6 years without having the gas drained out and it gunked it all up.

I was having the exact same problem about seven months ago ... the car would stutter anywhere between 3500 and 4500 rpms at around 50-75% throttle right? Tell me if Im off base or not ... I was told to change the MAF sensor (replaced it twice), i was told injectors (ran sea foam and even went to the dealer to have them clean them), was also told spark plugs (replaced them), was also told to clean the TB, and i think the last thing I was told to try was to replace the ignition coils ... at 150 a piece not fun ... nothing helped. Right now Im in Iraq so Im having a mechanic buddy try and fix it - he said that i was most probably the speed sensor so he swapped that and is going to test it this weekend. If that works Ill hit you up.

Ahh forgot one thing - check your ground connections on the battery and the frame. The drive by wire thorttle motor causes some hesitation at low speed small openings because of a weak ground on a lot of tCs and maybe it can cause your stutter also. It is after all a drive by wire system and you holding the pedal steady does not mean the throttle butterfly is doing exactly what you think it is supposed to do.

Yea sounds excactly the same as what im having a problem with. I was thinking about the coil overs but like you sayed at a 150 apiece no thanks. On the coil overs tho i have one that is kinda oxidised where the others are all nice and black. wasnt sure but was thinking that it may be one of thoes. Yours isnt throwing any codes either is it ???? mines not.
Also wanted to say thank you for serving over there. Im in the National Guard here in Missouri and havnt had to go yet. I know my time is comeing but till then thank you and good luck

Ill try that idea. I was also wondering if maybe the pedal sensor is a little worn or dirty in the conectors? I drive a over 130 miles a day and there all pritty much hwy and running around the 3500 mark so was thinking that may the problem. im taring into it today so going to go thru and clean every think and see if the problem goes away. heres hoping

Yeah that's a good idea, things can wear out. You could probably rev the engine and watch the throttle control moving the butterfly too or take a video of it to see if it is moving around at that rpm.

No, I wasnt throwing any codes at all thats why no one could really help me. As for the ignition coils i dropped the money on buying them and it didnt help at all, so IMO dont go for that. I would definitely try out the pedal sensor too cuz if I remember correctly my butterfly valve in the TB was definitely not moving like it was supposed to ... you could hear the intake of air but the valve wasnt even budging til about 50% throttle. Like I said mines getting test driven this weekend so we shall see what happens from that end. Oh yea, have you noticed any loss in power, kind of like the motor is atrophying? I felt my car start doing it a while ago, but kept driving while I was attempting to fix it (I couldnt leave it overnight anywhere due to where Im stationed) and after about 30,000 miles like this I test drove a brand new Tc and felt a considerable difference in power

Yeah but with drive by wire you can't be sure if the engine is running properly or not because you don't have direct control of the throttle. It (the ECU) could move it less with the same amount of pedal input and it would feel sluggish but not be.

so just got a test drive done on my car turns out the major problem was my cat. THe guy said it was so blocked up that then engine during acceleration was not able to exhale properly and as such the 02 sensor was freaking out and thats where the problems started ... which would also explain why it got worse as continued to drive for another 30K miles. Something to look into.

Don't know if thats the whole problem. My cousin (who has been the go-between since im deployed) said that it fixed the problem 90%. Im trying to figure out if that is a Cover My @$$ statement or what

hmm.. another reason to not have cats lol..

and the cats are covered under the emissions warranty! you shouldn't have to pay for that at all :)

Got the full story on the cat problem, apparently what is was is this: While the car was warming up at random one of the cylinders was missing so the engine was dumping fuel into said cylinder which was then being dumped in the exhaust. Endstate with that was the fuel was getting into the cat and the exhaust temperatures combined with the fuel caused the cat to melt ...

^^^
yup makes sense.. so did you get it warrantied or they denied you?