my ve loses what feels like half its power after driving it hard (high rpm) or driving it for awhile. it runs good and pulls hard for the first 20 minutes or so of driving but then power goes to **** almost always. turning the engine off and starting again seems to fix it temporarily, but then it will go back to running like junk. i tried to pull codes but got nothing (55). i have replaced the faulty injectors and the cracked coil packs, so it is running on all cylinders all the time. does this sound like knock sensor symptoms? sometimes i also hear what sounds like an air sucking sound on acceleration, i'm not sure if this has anything to do with it. vacum hoses look good, power valve works. when it acts up, the exhaust is more deep and bassy than after i first start it up when it runs fine. i'm surprised this engine would even run when i bought it. had 3 cracked coils, 2 dead injectors as well as this problem. that's what i get for $700 i guess.. it's my birthday help me out thanks for any input.

 

Yes, seems like knock sensors is a good guess.

Same thing happened in a Supra I was driving. Mid-boost suddenly the egts and thus boost/psi skyrocketed but the car slowed down even with the foot to the floor. Sometimes I'd have to turn the engine off to "clear" it and sometimes it'd "clear" itself. It was long ago so I'm not sure if I recall the solution exactly, but if memory serves me well I think I re-wired them to solve the issue.

 

do the knock sensor test silly.

 

are you referring to the diagnosics tests in the fsm or some other test? seems the only test other than digging down to inspect or replace the sensor is a continuity test which if it failed that, or really, any other of the tests, it seems the ks code should definitely be stored which it isn't..

 

I think he means the 470k resistor test...

 

I have driven with the harness totally unplugged and no CEL came up.
our cars ECU rarely stores any codes.

 

ok, i unplugged the harness and drove around. it drove pretty sluggish like it does when it's acting up. the check engine light never came on. i came home and checked the resistance between point A (+) on the harness, and a ground point as shown in the fsm. almost hit the 1,000,000 ohm mark, probably 8-900k. it should be at 470k?

 

the knock sensor should be in the ~500k range.
so eithers yours or your harness is bad.

 

Ummmmmm....Huh?

 

reading > you

 

ok....

 

mine's knock sensor..

well i guess it's time to rip the plenum off for the 3rd time in a month. at least i know the source of the problem though. thanks for the help.

 

go a little lower this time.
the actual lower manifold has to come off too.

 

I know, but what's annoying is getting to the manifold. at least i won't have to worry about getting any injectors out though actually, since messing with the harness and plugging it in last time, it hasn't went into mode. probably just a fluke though.

 

whats the 470k resistor mean?could a k\s read good but still intermittinly
be bad?would a bad k\s cause hesitation?or smooth but no power? thks

 

Hello,
I am pretty new to the maxima, just got it in july. So far it has been a good car, its 5sp se. But i am having the hessitation on accel below 3000 rpm. Sometimes the cars pulls great, other day after i drive it for awhile it doesnt have any pull. So if it is the knock sensor, if i disconnect it and only run 94 octane gas would i have to worry? or is that not a good idea? sorry just trying to learn here.Thanks.....

 

since the thread's bumped i'll go ahead and mention that the car still has not went into hesitation mode since i messed with the harness to check the resistance. i've drivin it quite a bit since then and before, it would do it almost every time i drove. maybe it just had a bad connection after i plugged it back in while replacing the injectors... unplug, replug, clean terminals, jiggle the wires and maybe you'll get lucky like i did.

 

Don't forget to ck the cat. converter

 

it has crossed my mind that maybe it was clogged or whatnot due to the bassy tone when running like junk. prev. owner replaced the stock exhaust with some cheap midas system or some bs, but that wouldn't explain how turning the engine on and off fixes the problem.. anyway, i'll probably just sell the car as is. it needs too much tlc and i miss my vg.