Alright, here's the problem, when I'm driving and shift into 2nd
or any higher gear and accelerate from about 2k it kinda feels like my car has turbo lag,(no throttle response, sluggish) I'll push pedal and it kinda hesitates for a second then it will pick up and go at about 3.5k-4k. I recently did all the 60k tuneup and I've been searching on here for the last couple days.
From what I've read I think it's either the Knock Sensor
a coil going or maybe injectors. The car is a 97 with 80k miles
Also it doesn't idel that smooth, it doesn't shake the whole car, but
when I put my hand on the shifter I can feel the rough idel.
I plan on checking for codes soon. Also I never get a CEL, I know the KS usually doesn't trip it but what about the others.

Any thoughts anyone.

 

I think its normal. If you look at a dyno plot for our engines, theres a slight decrease in the slope around 2.5 - 3 thousand rpms. I have the same hesitation around there.

 

You've picked some of the most likely culprits. Start diagnosing.

I had a malfunctioning coil that caused the same symptoms you described. It tested bad on the multimeter, was replaced & no more hesitation.

Good luck & keep us posted.

PS: You said you did the 60k service. Did you choose the right spark plugs/correct heat range? Did you gap them to Nissan specs? No offense intended: either of these things could cause a rough idle.

 

me too

 

I have this same loss of power between 3-4k rpm's. No codes. Replaced fuel and air filter and cleaned throttle body. I think it is dirty injectors. Car runs well otherwise, 49,000 mi.

 

has anyone ever tried the pressurized injector cleaners? the kind where you hook it up to the fuel rail and the car runs off a high pressure bottle? those are supposed to clean injectors and carbon deposits anywhere in the fuel\combustion line in the engine.

 

Yes, I used NGK coppers (BKR5E-11), they were pregapped by nissan
to .039 but I regapped them to .044, could that be the ploblem, I
believe thats as wide as you can gap them. Also, did the bad coil
make your idel a little rough , I'm thinking thats the problem.
Thanks for all replies.

 

Did the rough idle and driveability problems start occurring after the 60k sevice was done, or were they happening before?

I'm not familiar with the NGK copper part #, but if you verified compatibility, I'd bet they're fine.

Gap specification according to Haynes is 0.043", so you're pretty close on that - I doubt that's causing the problem.

Honestly, the one bad coil didn't really affect my idle too much - it was really just the hesitation under WOT that was noticeable. People who have had more than one coil fail have reported more problems with idle. Also, fwiw, I never got a CEL or any codes on that bad coil, even retrieving them manually. It was definitely bad, though. Resistance was off the charts.

Check it out, but also check the other items you mentioned - coils are easy to check with a DMM (digital multimeter).

 

It seems like it started recently because right after I did the
60k tuneup I noticed that it was a lot smoother than before.
As for the plugs these are the recommended alternative to
platniums that a lot of people on here use.

The car actually drives pretty normal, just feels sluggish when
in lower RPM's, like a small turbo engine with turbo lag, at WOT
I haven't really noticed hesitation, but maybe there is I have to
pay closer attention next time I drive. This makes me think that
the KS is bad and is retarding my timing.

I will check for codes ASAP but it's about 10 degrees outside and can't pull into the garage at the moment. Any other thoughts anyone, just finding out what you guys think of the top of your heads.

 

my car does the same but mine is auto ,,is this normal for autos?It has a turbo lag effect under WOT ,I had a freind one time in my car and he tought i had a turbo in my car because of the lag..It also does it when Im going like 25mph and i step on the gas hard it'll lag for a second till it begains to pick up..is this normal?

 

If you are referring to a manual transmission, I think your situation is perfectly normal. You're saying that you have weak acceleration after you shift and are at 2000 RPM. The real power doesn't kick in yet, so it makes perfect sense. If you want acceleration power, accelerate to 5000 in each gear before shifting, and then you will land in the powerband after you shift, giving you better acceleration. If I misunderstood the problem, please clarify.

 

That may be partly the problem ( not all the way in the power band
yet) but I recently drove a 99 5 speed and mine seems kinda sluggish
compared to that, probably cause more theres more miles on mine.

 

my car has a very small bit of hesitation. it is not really common either, say i am in 1st going 15mph and decide to floor it, i hear the engine go, and the car goes, but then its like it snaps and really goes. at higer speeds and in higher gears it is not very noticable. i have a frankencar that has a clean filter, new fuel filter, new pcv valve, no exhaust restriction, so i think it is my injectors, or possibly plugs\coils. but most likely injectors. other than techron, anyone want to suggest a good injector cleaner?

 

Perhaps the clutch is slipping a little then catches Mine
slips sometimes so I'm thinking this may be part of my problem

 

hehe, ACT=Opposite of slip

i am quite positive i have no slipping, it really feels like there is a clogged injector that just takes an extra millisecond to spurt at WOT.

 

there is nothing wrong with your car...
you shouldn't be looking for power at 2k rpm cause there won't be any.
what you need to do is downshift to a lower gear for more power if need be.

 

Shouldn't the car accelerate smoothly though the rpm range, it's
almost like the car takes a second to think about it then goes.
Also I'm not flooring it from like 10 mph in 3rd and thinking that
its going to take off as if it was in first.
Am I wrong, does anyone elses do this.