Hello all,

My 99 Maxima 5 Spd.(SE Limited) with ~100K Mi on it stumbles under moderate to heavy load. Feels like the clutch is slipping, but I don't think it is as the RPM don't increase. The check engin light went on for a few minuets but went out.

It idles fine and under normal driving situations it runs great.

What can it be?!?! I did some searches but came up with little.

Any help would be welcome.

Chris D

 

99 SE-L with 100K on it? Man you sure do drive.

Pull the codes from the ECU - it stores them. The light went on for a reason. The stumble could be your knock sensor acting up.

Heavy load = More gas = Chance of PING = Knock sensor retards Timimg = there's your stumble.

Then again, why are you pinging.... Are you using 91 octain gas?

Tune up status?

Please don't tell us your running with Bosch plugs....

 

Yep... My Ex girlfriend lived 168 Mi (each way) from me, and work was 45 (each way)... My curren GF is only 40Mi away...

I pulled the codes and it came up with nothing. (I got the got the codes off this forum).

I did replace the plugs with Boch Platinums +2's, BUT the prior plugs did the same thing. The seem better than what I had...

What is wrong with the Boch's? I always thought they were good?

Chris

 

The Bosch may not be your problem right now, but do yourself a favor and take them out!!!! I've witnessed first hand what can happen to them in the VQ motor. Our direct coil ignition is very hot and can burn up the Bosch plugs very quickly. My buddy has a 98 I30 and I put Bosch in there, 12K later he started to have hard starts and poor fuel mileage. Much to our suprise the Bosch plugs had no electrode left at all. Just gone.... There are a few others who have had the same experiance with Bosch plugs.

Now back to your problem. You may be in need of a fuel system cleaning. Not only the throttle body, but the injectors as well. I do belive Nissan can do this service. 3M makes a great system, if you can find a local garage to perform this, have it done. It yeilds excellent results!!

Good luck!


P.S. Take the Bosch plugs out... Use only NGK..

 

I'll change out the Boch for the NGK next time I spend some time under the hood.

I replaced the fuel filter a few months back (this prob has been going on for a while), again no change along with using some fuel system cleaner every few fill ups (no not as good as the power process from a dealer can do).

Oh, this problem starts around 3K RPM.

My wild guess was a igniton problem, bad coil. So, your thinking fuel system?

 

If it was a coil you'd be getting the CEL light on and it would indicate the misfire.

I'm thinking fuel system, but I'm now starting to think it may be your cat. You say it starts at around 3K RPMs' When a cat goes bad it clogges up. The exhaust can't get out of your car and you get the lag. Might wanna toss that idea around as well.

 

Hmmmm.... You might be on to something there....

I noticed that the CAT a few weeks ago was making that "over heated noise" (poping/krinkling).

I can rev it up to 5K+ rpm without a prob (and do/have often) with little load, would that make a differance?

Sorry if I'm tossing stuf back out, I'm a engineer ;-). I just want to narrow this down and fix it myself.