Setting TM back to stock had no effect.

Here's what happened on my 100% stock file:

06302008_160907 from sabrewings -- Scan Depot dot net

Question. I've just been doing partial writes. When I loaded my stock file back, I didn't do anything about the fuel trims either. That shouldn't really make a difference with PE should it?

What could be causing knock in PE like this??? Something mechanical?

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Just a thought... Could this be a bad gas issue? I don't use much fuel. A whole tank will last me three weeks since I work very close to where I live. I recently just refilled from the same gas station (an Exxon) I always gas at. So, if there was something wrong with their 93 I'd be running that fuel for a while.

I've got a 6 hour drive coming up so I'll be able to clear this tank pretty quickly and get a new tank in Memphis. Following this train of thought (as I was just resting my head on my desk), I remember my friend commenting that my spark advance was awfully low. Could I be running on my bad_fuel_spark table? If my PCM thinks I have bad gas, I probably do...

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

I always copy my high octane spark table to my low octane just so the timing stays where i put it. imo bad gas could not cause that much kr. this is not directed twards you or anyone on here but why does everyone always talk about bad gas? what is bad gas? Like how is it different from regular gas? I think gas now a days has a pretty high q/a control on it. just my thoghts. i'v never had bad gas to my knowledge. good thinking though...it's probably the smallest that you and everybody else have over looked that is causing all of this lol.

__________________
1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

Bad gas doesn't have the octane rating it claims, or it has some sort of contaminant limiting its power. Some bad gas you car can barely run on, other gas causes knock (also known as "hot" gas). Put simply, I can think of no reason mechanically why it should knock like this with the settings all returned to stock.

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

wideband. you need one.

__________________
98 XGT - 3.2/3.4, s&s, ported m90/TB/LIM, 1.9s, jp dbl; tinted, blacked out, lowered
soon -> e85, meth, and a lot smaller pulley

Why? Obviously I have issues beyond tuning because a completely stock file and its still going berserk and it didn't used to do this. I have a mechanical issue and a wideband is a waste of money in trying to find it.

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Here's a scan to look at. I went out on my stock file again, a complete write instead of just partial. Still seeing the same issues, but this is a nice long scan with all the values. Maybe someone will see something. One WOT run, a few 60-65% TPS runs, and a good bit of cruising.

06302008_220607 from sabrewings -- Scan Depot dot net

I added some fuel treatment stuff (couple bottles) since it was at the onbase shoppette for cheap. Hopefully that'll keep it good enough to run home on. I'm also topping off at a Chevron this time before I leave.

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Do you have an old scan when it was not messed up?
What did you install when this started?
Keep the stock bin in and rescan the car. Compare it to an old scan if you have one.
lets find out why this is happening before we start chasing our tails in a tune.

webracin

__________________

2001 Grand Prix GTP
ZZP HUB 3.2 3.4, ZZP 8 Rib conversion, JC 3" DP Gen 2 cat & U-bend Delete, Accel Super Stock 8mm wires, DHP 1.5, 180* Thermo, Throttle Spacer, SS Intercooler, ZZP Fuel Rails, SLP CAI w/K&N Cone, Dynomax cat back, ZZP Tranny.

2000 Grand Prix GTP Daytona K&N, Flowmasters

Here's my oldest scan. Unfortunately it's still doing it. Also, unfortunately, based off the date, I could be running the same bad gas.

06062008_113751 from sabrewings -- Scan Depot dot net

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas

Holy ****. Do I have to run this freaking rich??? I found this scan. I chopped out the part I want you to look at...

possiblesolutionpe from sabrewings -- Scan Depot dot net

Note how the AFR keeps dropping and O2s are climbing... the, at about an AFR of 10.4 it starts dropping off and the AFR finally hits about 9 with O2s in the nearly 960 range. I have to run THAT freaking rich?!?!

Edit: Or look at this one. Same thing happening, but it gets down to nearly 8:1 and my O2s are up over 960 and the knock is practically cleared you can tell by the rate at which it's recovering. I'm so excited I can hardly contain myself. I had no idea I had to be that rich, but whatever tune I was on at that time was working.

http://www.scandepot.net/viewscan.php?pk=5156

__________________
2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas