01 QX4 Power Loss at 4500 rpm

[nugget63]

I have been reading the posts for a while and they helped me with several problems so I am hoping I can get help with this.

At 4500 rpm I lose power. The engine will stay at this rpm but will not go higher. Below this rpm the engine seems to run fine. This only occurs when driving...not while in park.

The car has 102000 miles. I recently changed the spark plugs, fixed a p1140, used fuel injector cleaner, new air filter, put sea foam in the crank case.

I changed the fuel filter about 40,000 miles ago and am thinking of changing it. But I think the problem may be vacuum lines. Does anybody have ideas?

Thanks.

[nugget63]

I forgot to mention that the SES light is not on.

Thanks,

[KoukiS14]

Unhook the 9,000 lb horse trailer from the back of it. Then try.



Actually I have no idea -- welcome to NICO!! Hopefully someone has seen this problem.

[pathfinder_se_black]

Unhook the 9,000 lb horse trailer from the back of it. Then try.



Actually I have no idea -- welcome to NICO!! Hopefully someone has seen this problem.

roflcopter

hmm have you tried cleaning the throttlebody? it's worth a try

[nugget63]

I just bought a new fuel filter. I will try that and try cleaning the throttle body.

Any tips on cleaning the throttle body?

[nugget63]

Replaced fuel filter and cleaned throttle body (thanks for the idea) with no change. Also wondering if it could be the timing chain. Any ideas.

[pathfinder_se_black]

hmm it could also be the cataletic converter, you can check that if the exhuast sounds alittle louder than usual.

[SnowSurfLax]

If it was the catalytic convertor, wouldn't it also hamper it when it's in park? If it's restricting the flow it shouldn't matter if it was in gear or not.

[nmgoodthing]

Is your OverDrive button on your shifter turned off?

[KoukiS14]

Is your OverDrive button on your shifter turned off?

Maybe the 01+ is different, but that wouldn't create a power loss, and the thing resets automatically once the vehicle is turned off.

[Andrew502]

Is that a vg33e? Mine does that only when I go into 2nd gear but closer to 4000-4300k. It's seems like it takes longer to get from 4000 to 4300 than the rest of the rpm range. But the car will continue to pick up speed regardless.

From what I remember, the 33 produces the most torque at that rpm, so it would make sense for the engine to hold at that rpm longer, if the gearing was designed that way.

I always thought the 33 was a cam short.

[GoodOmens]

Take it t a autozone / advanced auto parts and do a free computer scan.

Some things (Like a bad knock sensor) won't make the SES light come on.

[KoukiS14]

Any updates? Just hoping you're qx is feeling better.

[slickroger]

hey you seem to be having the same problem im having with my 01 pathfinder. there is another post on the third page about "pathfinder loss of power". apparently that dude found a solution. i havent had time to do anything myself yet but what he came up with might help you. let me know if you have any luck

peace

Life is Blunt

[pathfinder_top_gear5]

have you changed your timing belt yet?

[KoukiS14]

have you changed your timing belt yet?

I'd probably go ahead and change the glow plugs while you're at it.

sorry.. The 01 has a timing chain that doesn't need replaced. . I wish the VG had that.

[greentrbo95gst]

You need to replace your MAF.