Hesitation between 3k to 4.5k rpm + Fueling issues??

[antgtir]

As the title says, i have been experiencing some slight hesitation between the 3k and 4.5k rpm mark on partial throttle, if i put the car on full boost it drives through it without even feeling as though its holding back.

I have recently changed the plugs to the colder grade 8 option (NGK) but to no avail. I have now moved onto the injectors and have sent some treatment through them but at the moment i can still feel the hesitation:?

I did notice that when i removed the plugs they were white and so the car seems to be running lean this i feel is down to another prob i think i have with my actuator sticking as boost is going over standard on a pretty regular basis. This is not just 0.1bar overboost but seems to be reaching 1bar at least.

Now before the usual suspects start to rant ahhh 1 bar mong lol, the pressure its reaching is not my concern its the fact its getting to this pressure without any control on the fueling side of things. So i firstly want to remove the fueling issues and reason for overboost before i then strap on the controller.

Has anyone experienced an overboost problem like this before? If so could you give me some reasons i.e. actuator sticking etc etc.

Also with regards to the hesitation, as i can drive through it and have no problems on boost (or overboost for that matter) i am assuming that there is some form of restriction somewhere (remember it is only slight, not like a fuel pump rate restriction), so if you have any ideas with regards to this little annoying problem please let me know.

Looking forward to the suggestions;-) :-D

Ant.

 

[Fusion Ed]

Have you got standard air box or aftermarket filter etc?

 

[paz]

Hiya fella, I'm assuming you've done the usual service bits and pieces like changed the filter element and done the leads, dizzy cap, rotor head etc? I used to have a slight hesitation/misfire before I did my service a few months ago.

Paz

 

[GtiR`BoD]

i had it from small amount of air leaking around i/c pipe work, worth a look

 

[antgtir]

Have you got standard air box or aftermarket filter etc?

Ed, I have an aftermarket Apex-i Cone Filter mate, ive had it on for a while and before i noticed the hesitation:?

Hiya fella, I'm assuming you've done the usual service bits and pieces like changed the filter element and done the leads, dizzy cap, rotor head etc? I used to have a slight hesitation/misfire before I did my service a few months ago.

Paz

I have changed the plugs only 400miles or so ago to the grade 8's. I closed the gap on the plugs as my old ones were lets just say a bit sloppy lol, so doing this i thought may help but its still there.

The leads, rotor arm and dizzy cap i must admit i did well over a year agao maybe more so i wonder if its one of the leads starting to break down:? I shall dismantle asap i think and have a little look see. Cheers.

i had it from small amount of air leaking around i/c pipe work, worth a look

I shall have a check when i look at the other consumables paz suggested, cheers. I must admit the overboost is a bit more frequent so i wonder if this is contributing to this??

Thanks for the comments guys, have any of you had any experience with the overboost due to maybe sticky actuator problem before??

Ant.

 

[Braveheart]

In responce to antgtir issue regarding "Hesitation between 3k to 4.5k rpm + Fueling issues??" I had a similar problem.
I picked up a GTIR last month and felt it was running a bit funky. It seemed to pick up ok at low revs but stuttered and hesitated badly between 4.5 - 5k rpm. When I layed off the gas the damned thing wanted to go. Not good when you are entering a corner looking for engine breaking. It was also idling high (1100rpm) and just felt a bit unwell.
The car it's self is bulk standard except for a mongoose exhaust (without cat) and sump guard but with a poor service history (jap 18k service). I bought it off a farmer who had owned it for 4 years and done 2k miles in that time. It has 60k on the clock, it was imported in 2002.
Anyway, given the service history and poor performance, I booked it in for the full boona.
Falkland performace changed all the fluids, plugs, point, air filter (now K&N) front disks and pads and rear pads. (disks and pads were well shot.... it was grinding along)
I was full of hope but the car was still running poorly.
It turned out to be the knock sensor (error code 34) This sensor they explained was there to pick up pinking etc and when triggered would retard the ignition timming by 6deg. It's meant to reset it's self but did not and I thing I will source a new sensor.
They reset the ECU and the error was gone. The car is now running fine. Much smoother, pulls all the way through the rev band and thankfully enters engine breaking now when I gas off. I did refrain from taking it out on the track at knock hill last sunday however as I have a sneaky suspition the problem would return plus I did not want to buy another set of brake pads so soon.

Hope this information helps and I may post it in a couple of other places on this web site.

Lang may your lumb reek... all the best Braveheat (Scott)

 

[antgtir]

The hesitation is very minor, doesn't feel as though the timing is being reset, plus i have an SAFC 2 fitted which is spliced into the knock sender wire read by the ECU and that isn't reading any knock at all.

I must admit though i haven't conducted an ECU check so this may throw something up, i shall carry out this and let you guys know if there is anything:?

Cheers for the replies.

Ant.

 

[Braveheart]

If it is the knock sensor, Nissan can supply but it's a wopping £206

Part Number 22060-30P00 (all zeros - no oooooooo's)

 

[azboy]

clean ur maf earths on the intake manifold but this is prob ur maf on its way, close up the pins in the maf to make a tighter connection and spray wd40 over the plug once on the maf so it keep any water out from ur bonnet.

 

[azboy]

the det sensor will show a fault up the maf wont unless very bad but as long as its withing its working tolorances it wont show as a fault ie between 1 and 4.8 volts