Maxima Forums - View Single Post - Power Surging During Acceleration (~3000-4500rpm)

*mowgli29* · 07-14-2008, 01:25 PM

this sounds similar to a problem of mine...but not quite the same.

My car has done this since I got it about a year ago. It did it stock, and it still does it now. For me, it happens when I'm cruising (usually between 40-60) and I let off the gas and then hit it again. Sometimes it does it, sometimes not. To me it always felt like the motor was rocking back and forth on the mushy mounts...especially because I almost had to hit the gas just right to get it to do this. It feels like it gets in a rythm of rocking back and forth and then after a couple seconds it will stop and you'll actually accelerate. It usually happens a bit lower in the rev range for me, but I can get it to do it above 3k.

Well I installed ES poly mounts and it's just the same. Sometimes it seems like it might be worse. Now I'm looking for another cause...

the problem persisted throughout the following:
-two different stock MAFs
-one modified MAF
-USIM+4th gen TB and TPS
-00VI+5th gen TB and TPS
-stock rear coils
-5th gen rear coils
-4th gen IACV dirty and clean
-4th gen and vq40 injectors

The only thing that hasn't been swapped are the front coils. I'll try it, but I have a feeling it won't change anything. And yes, I have a CEL, but the codes are EVAP related, because I never re-installed it after the 00VI.

One thing I've wondered about is the Knock Sensor. I currently have a resistor in there because (it think) the lower harness went bad. There was a point in time that it was loose and over the period of a couple days, I could tell when I had a "working" KS and when the resistor was not making contact, resulting in it feeling gutless. Is it possible that the resistor may be too loose and it causes the engine to stutter when I hit the gas abruptly?

I have no idea WTH is going on. I haven't pursued it because it doesn't affect performance. At WOT in 1st - 4th gears, it doesn't happen (ok well SOMETIMES when I slam it into 3rd at WOT). Mostly when cruising and I abruptly hit the gas. Mostly in gears 4 and 5, sometimes in 3.

I'm tempted to take the hood off and go for a drive to see if the motor is actually rocking...

07-14-2008, 01:25 PM	#7
mowgli29 VQ is my anti-drug. 97' Maxima SE Join Date: Jul 2006 Location: St. Louis, MO iTrader: (21) Posts: 1,161	this sounds similar to a problem of mine...but not quite the same. My car has done this since I got it about a year ago. It did it stock, and it still does it now. For me, it happens when I'm cruising (usually between 40-60) and I let off the gas and then hit it again. Sometimes it does it, sometimes not. To me it always felt like the motor was rocking back and forth on the mushy mounts...especially because I almost had to hit the gas just right to get it to do this. It feels like it gets in a rythm of rocking back and forth and then after a couple seconds it will stop and you'll actually accelerate. It usually happens a bit lower in the rev range for me, but I can get it to do it above 3k. Well I installed ES poly mounts and it's just the same. Sometimes it seems like it might be worse. Now I'm looking for another cause... the problem persisted throughout the following: -two different stock MAFs -one modified MAF -USIM+4th gen TB and TPS -00VI+5th gen TB and TPS -stock rear coils -5th gen rear coils -4th gen IACV dirty and clean -4th gen and vq40 injectors The only thing that hasn't been swapped are the front coils. I'll try it, but I have a feeling it won't change anything. And yes, I have a CEL, but the codes are EVAP related, because I never re-installed it after the 00VI. One thing I've wondered about is the Knock Sensor. I currently have a resistor in there because (it think) the lower harness went bad. There was a point in time that it was loose and over the period of a couple days, I could tell when I had a "working" KS and when the resistor was not making contact, resulting in it feeling gutless. Is it possible that the resistor may be too loose and it causes the engine to stutter when I hit the gas abruptly? I have no idea WTH is going on. I haven't pursued it because it doesn't affect performance. At WOT in 1st - 4th gears, it doesn't happen (ok well SOMETIMES when I slam it into 3rd at WOT). Mostly when cruising and I abruptly hit the gas. Mostly in gears 4 and 5, sometimes in 3. I'm tempted to take the hood off and go for a drive to see if the motor is actually rocking... __________________ 2002 Platinum Silver Metallic WRX VF34, STi Pinks, TBE, UP, ACT Fly, Prodrive 04 Reds, Seibon hood and lip, UTEC Tuned @ 19psi 1997 Rosewood 5MT SE - totaled. 1995 Sage Mist Green GXE - sold. 1990 Ruby Pearl SE - sold. FOR SALE! http://forums.maxima.org/4th-generat...-cleanout.html Last edited by mowgli29; 07-14-2008 at 01:32 PM.