Hi guys,

This is my first post -- been lurking for a while, I've made sure to read the stickies and FAQs, etc. :-). Anyway, I've got a 2000 GXE with about 64K miles on it that pings (most of the time, not always, and there doesn't seem to be anthing connecting those, say, 30% of the times where it doesn't) pretty dramatically under heavy acceleration in any gear. It starts at about 2500 RPM and continues as far up as I've gone, but only when the throttle is fairly wide open (don't need fully wide open throttle, but maybe halfway). There is a power loss that feels like the computer retarding the ignition timing once the ping starts that lasts basically until I turn off the car and let it sit (presumably resetting the ECU's short term memory).

Had one bad coil replaced at about 54K, and my O2 sensor replaced about 2000 miles ago. Since then, no SES light. I've even taken it back to get it hooked up to the computer to see if there were stored codes that didn't throw a light (knock sensor, perhaps MAF, etc.). No codes at all were stored in the computer, everything checked out. Naturally, that day was one of the times it wouldn't ping, so my mechanic couldn't make any conclusive guesses without me leaving the car, which I couldn't do. I then cleaned the throttle body and MAF wire; not much help. I've replaced the air filter with a drop-in K&N filter; no help. The only thing that does seem to help is connecting the stock air scoop to the airbox more tightly (the scoop doesn't seem to naturally want to stay connected to the airbox or the pipe bringing air in from below). Immediately after hooking those up tightly, the pinging is gone, and full acceleration is back. However, the condition deteriorates after less than a day.

Basically, I'm wondering what could be causing the pinging and slow, uneven acceleration that goes with it, but wouldn't throw any codes at all. Incidentally, I've got a Berk intake on the way; I'm hoping that by removing the need for the scoop to be coupled so tightly to the stock airbox, I'll be able to get enough air into the engine and stop the pinging (but then again, I'm not even sure that's the whole problem, so...) . Anyway, I'm totally stumped on this one. Any thoughts? Thanks!

-Matt

 

It sounds like bad coils, I just replaced all six because of the hesitation when accelerating. Problem solved, and I didn't have an SES light. I have read alot that it's best to replace all of the coils because when one goes bad the rest tend to follow good luck!

Robert

 

Thanks Robert,
Yeah, I'm afraid of it being coils as well. I'd just rather not spend the money to replace them if they're not going bad yet -- is it possible that I have a bad coil (or coils) without it even storing a code in the computer? I was under the impression that you'd still get something like the "primary ignition failure" code stored, even if the SES light didn't go on.

-Matt

 

are you using 91 octane gas or better?

 

Yes, nothing less than 93 ever goes in. I also put in a can of BG44K after replacing the O2 sensor.

-Matt

 

I got the same problem as you with mine......i lose a lot of power after 3000 RPM like if the engine is choking, sometimes it pings, some it doesnt but it sure feels like computer retarding the timing.
I have cleaned TB and just installed a CAI intake, which is making it more noticeable now......No SES for me neither, using 93 octane.

I am going to try to change in-pump fuel filter next, but I dont really want to change all coils unless i am absolutely sure....

I hope we find out what this is before I ditch this max into lake!!!

 

Kiosk,
That does sound similar. In my case, during the relatively few trips when it's not pinging, everything is ok -- no loss of acceleration or hesitation. Is that the case with you, too?

Thanks to everybody for the quick responses...keep 'em coming...

-Matt

 

No, mine will sometines not ping and still bog down pretty bad. I still think is the computer seriously retarding the timing to keep it from pinging thou, not good one way or the other. I dont want change out all coils just to find out that isnt it, I would definitely not be happy after that.

 

I hear ya I debate shelling out $240 for the coils (twllin 5th gen FS) but I'm at 84k so I figured it was time anyway. Like I said I didn't have an SES either but from all the symptoms that I've read on the org it sounded right to me.

My car accelerates 100% better now. I even got my "kick" back when you floor it and shifts to second! God I missed that didn't even realize it was gone but the first time I floored it with the new coils it felt like it was new!

Not much help but good luck...BTW have you replaced your plugs yet mine were shot around 55-60k?

Robert

 

Similar symptoms which resolved once I replaced all 6 coils, but did have SES (P1320)

 

Robert,
Yeah, I changed all 6 plugs when I replaced the one coil. One question -- you didn't have an SES light, but do you know if you had any codes stored that didn't trigger the light? It's just that I didn't have anything in the ECU...makes me wonder if it's not something else.

Also, it occurs to me that I never mentioned that the Max is a 5-speed (so it's not an AT slippage or anything like that), and that I went through all of the TSBs with my mechanic -- the only one he thought might apply was the coil TSB, but the symptoms don't match (there's no misfire code stored).

BTW, thanks a ton for the quick responses!

 

So, does anybody have any ideas besides bad coils? Since there are no codes stored, I'd still like to think it's something else...

 

im in your area and have new coils ill sell you if you want them.
it might be a dirty throttle body

 

soonerfan,
Thanks...if it turns out that I need the coils, maybe I'll pick 'em up from you. It's not the throttle body -- mentioned above that I cleaned that just recently, and it wasn't that bad when I did.

-Matt

 

Still no good. I've put on the Berk intake (which, by the way, is pretty cool) and swapped out the coils. No change. What else could it be?

 

Threads such as this are interesting. I am not trying to disagree with any previous post but how can pinging be related to bad coils? When the coils go bad, do they begin firing at undesired times? I am under the impression that they just lose their ability to fire the plug when they begin to fail. If the second is true then I don't see that the coils are to blame, but then again I haven't had bad coils...... yet.

Again I am intersted in this post; I get LIGHT pinging under part throttle sometimes and always run 93 octane. I find it hard to believe that Nissan would tune a car that close to the edge of detonation, especially when I read all the threads about how rich these things are tuned.

 

Hey, as you know I have the same problems as you. I see a lot of posts about people having problems with the MAF....i wonder if a bad MAF is trickin out the ECU to retard the timinng....I am convinced that my problem is and air/fuel ratio disagreement between the ECU and the engine, thats why the ECU is retarding the timimg and giving me the loss of power.
I am going to try the fuel path first now and change my fuel filter (or strainer) in the tank. Not sure how to check fuel injectors thou
If that doesnt do it I am going to try out a new MAF....

I always doubted it was coils.....in my opinion bad coils would give u problems all the time, not just under WOT.

I'll let you know how it goes, doing some work this weekend.

 

Did you swap out the coild with good ones? Were they new or used coils?

There are two other things I can think of. One would be carbon build up on a piston(s). If you know anyone with a fiber optic scope, you can pull the plugs and look in the cylinders. The other is a bad injector, leaning out a cylinder.

The power loss you talked about should only last as long as the knock sensor registers knock. The ECU will yank timing when it detects > ~6 knocks per second. Once that condition doesn't exist, it returns to normal timing.

You hear about unexplained pinging on many different makes of cars. No codes, everything looks great. I had it happen to one of my other cars and none of the mechanics I took it to (including the delaer under warranty) could ever fix it. It seems that they can't do much unless it throws a code. Even then, they suck at diagnostic work.

I just can't beleive that mechanics don't have protocols to look at for solving ping situations like this since it happens a lot.

Personally, I would scope the cylinders. If you find a hot spot (carbon), remove it.

If that's OK, then I would have the injectors tested and cleaned (out of the car).

Good luck!

 

itdood,
W/ regard to the coils, I've swapped them out for grey-dot (new) coils. Thanks for the great post -- don't know anyone w/ a scope, but I'll check around, and I may be able to run it over to my mechanic early next week to check for carbon buildup or a bad injector.

Thanks, guys, keep the ideas rollin'...