My 'line feels hesitant

[go_nuts]

Howdy fellow 'line lovers, could anyone gimme some clues wtf went wrong with my whale? :Oops:

What I've done: pulled the AFM's and filters out for a nice bath. Drenched the AFM's with carby cleaner but it's one of those non-residual spray. Likewise I've cleaned the airfilter (no it's not a paper one). I was in the mood to tweak a thing or two so I moved the Nismo fuel pressure regulator by about 1-2mm but knowing I could screw things up, I've moved it back by 1-2mm so in effect I haven't moved it at all.

The problem: between 3-4k rpm the car hesistates for 1-2 seconds then become pretty willing to rev all the way to 8k. Idle before the cleaning was a bit rough but funny enough it's no longer rough, now purrs nicely. Back to the hesitate thing, it doesn't happen all the time, only happens twice in my 5 minutes drive (to make sure everything's running fine). At no time the car was running in limp mode so I am sure it's not a dead AFM thing.

Sums it up, the car idles better, revs easier than before but there's this hesitation in going up occasionally. One other thing I've noticed is, I didn't secure one of the AFM back in as securely as before but it isn't leaking as far as I could tell. Not sure am I paranoid or what, the car didn't feels as quick as before...:headspin:

Any ideas?

[Remix-]

Hrm, i seem to be facing the same problem of hesitation. I am going to clean my afm this weekend with carby cleaner, check my cat for blockages and check my fuel pump and fuel pressure in the lines. I do recommend that you consider resetting your ecu, i did this last week and noticed quite a difference in performance for the positive. Best of luck.

[JAPCAB]

perhaps spark plugs?