im new and i have a couple questions

[joshf78]

hi, i am new to the infiniti world, bought an 01 qx4 the other day. before that i had a 98 frontier, but it was a 5 speed. my question is this, i am not used to the autos nor am i used to the 3.5 v6's, but on light throttle this think is peppy as hell, but when you want to take off up the highway, putting your foot down harder it pulls hard for a bit but then the pull isnt there, but it keeps revving up until it shifts... quite late. what i mean is... it isnt slipping persay, its just not really making gops of power which youd expect. i had the intake apart today to check the bypass butterfly valves, they were fine, in fact i think they were already addressed, i could only get 2 screws out. i was actually thinking the valves werent opening or something. theres a definite lack of power either way. also, i do notice there is a very slight spark knock on very light throttle with a load, say going up an incline, but not really giving it much to do it. any more throttle and it stops. seems to be the passenger side bank, maybe even only one cylinder.
any ideas or insight to these?

[Towncivilian]

Replace your fuel filter (guide is in the pinned how to thread) and run 91 or higher octane to see if it helps the knock.

It's tough to apply thread locker with the lower intake manifold still on. I'd remove it and apply red thread locker to all screws.

Welcome to NICO!

[joshf78]

well heres an update. i had the intake off, and i could only get 2 screws out, the rest were too tight, and the 2 i got out i had to work to get them loose. they had a little blue on them, leading me to believe the thread lock was already done. while the intake was out i cleaned the intake and throttle body with spray seafoam. put a bottle of seafoam in the tank when i filled it. replaced the fuel filter, air filter cabin air filter, and i found a reciept in the dash for spark plugs being changed in september. i checked the transmission fluid, its perfect. so i took it out for a test drive. it still feels like when i am stepping on it, it'll take off like a shot at first, then level out power wise while the rpm's climb. like its still pulling but not even half what it was in the lower rpm's. if i keep it to the floor, it will kinda buck a little like its full power and then not. im wondering if theres a possible problem with the actuator for those power valves. maybe not opening when they need to. anyways, aside from that, i have to say i am overall quite impressed with the shape this truck is in, as well as the abilities it has. we are having snow every day here, it does just fine in it with michelin ltx m/s (new on front, half worn on back) and transfer case in auto.

[Towncivilian]

Okay, sounds like you're fine on the power valve screws then.

Check the power valve actuator vacuum hose for clogging or damage.

[joshf78]

i checked the vac line, it seems clear. there is an electronic soleoid that acvtivates the vacuum to the actuator, what rpm does the solenoid open?

[Towncivilian]

Power valves actuate around 40-50% throttle at approximately 2.5-2.75k RPM.