Thread: PE nuts

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?

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...

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.

wideband. you need one.

Originally Posted by Bio248

wideband. you need one.

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.

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.

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

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

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

my bad, didnt read into it that much.

why the crap are you knocking at 2000+ rpm?! your mod list doesnt reflect anyting that could be screwed up since your tune has good fuel trims. im lost.

i havent had much experience with tuning as i dont have any of the tuners/software, but something is wrong that youre knocking down low so much. that cannot be a tuning issue. when did you replace your o2 sensor last? fresh plugs? new wires? all the tune up stuff done?

Originally Posted by Bio248

when did you replace your o2 sensor last?

Never. Only got 67k miles.

Originally Posted by Bio248

fresh plugs?

Coming soon.

Originally Posted by Bio248

New wires?

See above

Originally Posted by Bio248

all the tune up stuff done?

Fuel filter not long ago, air filter is good, etc.

Though, I may have found my problem, crazy as it seems. See last post of previous page.

Also, according to this diagram, my injectors are breaking the laws of physics:



You can clearly see in one of my scans that at 5160.5 RPM my IPW is 25.28ms. My injectors are going practically static with the AFR the PCM is commanding, but its fixing the knock. I may see if I can tweak it as I don't think that low an AFR is required. Just that the RPM vs Time table was driving it so low. At least that's my theory...

Interesting development to say the least. It may be my plugs or O2 sensor are on the way out...

you should never ever max your injectors with your amount of mods. is it possible that one of your injectors is fubar'd or your fuel rail/line is kinked in any way?

i didnt really look, but how does your timing look? are you commanding something like 30* WOT?

I don't believe I have a fueling issue. I have no misfires recorded, and as the PCM commands a particular AFR the O2 sensor is showing its achieving that AFR. I'm just wondering why I need such high O2s to not knock.

I'm going to do some maintenance at home. I'm about to order PRJ wires, AL605 plugs, and a new O2 sensor. If that doesn't fix it, I'll do a fuel pressure test. Depending on the results from that, it might be time for new injectors (since I was planning on swapping to 04-05 L67 or maybe L32 injectors anyway before I start moving towards more mods so I always have the headroom).

Someone on the DHP forum brought up that it might be TM showing up. Does TM appear then go away at the standard KR recovery rate? Does it appear right as you enter PE?

I left a lot of my TM settings alone. I want my tranny to last, but I did adjust it so that it can't turn off injectors.

torque management does not create knock. it's a myth.

I have always been told that TM will appear to be knock, but its not actually. It tells the PC there is knock present so that it can control spark and fuel. May want to see what Overkill has to say.

webracin

Originally Posted by Bio248

torque management does not create knock. it's a myth.

We know it doesn't create knock, but there's strong evidence to support that it shows up as knock (since the "KR" value should be renamed "SR" or spark retard).

I'm very interested in what Will would say.

yeah, im at a loss to add any more onto that. i dont even own a tuner. ;p