Thread: PE nuts

Originally Posted by Reptile

Just to clarify something. KR could be a few things...TM will show up as KR in the PCM and here's why. Anytime that timing is pulled it shows up as KR. yup, it's as simple as that.

That's what I had heard.

Originally Posted by Reptile

Now, onto the problem. I honestly think that this deal is running way to rich for a n/a. If you're running too much fuel, some can be left over in the cylinder, and once fresh air/fuel hits it it could be flubbing up your AFR and your timing. It probably is knocking from all the fuel it's getting.

Okay, then why would it do the exact same thing with a full write of my 100% stock file? And the knock starts to go away the richer it gets. It seems that O2s in the 920-940 area have stopped it and the KR is recovering from then on. You can see that in the last scan I posted.

Originally Posted by Reptile

Put the VE back to stock
Put timing back to stock
Fueling back to stock
Raise all of your TM settings in your spark/fuel/transmissions tables...put them to the max.

I did all that by the full write with my stock file. Well, except the TM part. Why would adding TM make this go away?

I think we're on to something with the KR being spark reduction from a TM setting.

I'm heading out of town tonight, and I'm going to try a bin file I prepped last night. I took away the torque management's ability to pull spark (I think). Gonna see what that does.

As for the tables you're talking about, I know the two tables that say Max torque turbine locked and Max torque turbine unlocked. Both are filled with "1000" in each cell.

There's no way this is TM. There must be something wrong with the car, be it bad gas, a bad O2 sensor, bad plugs. Something. She's sick.

Look at this scan. It's so much worse today. I can hardly touch the throttle without knock now. I'll be lucky to be able to cruise on the highway with no knock.

07022008_154958 from sabrewings -- Scan Depot dot net

Got some more questions for you.....

Do you have a aftermarket downpipe?
Check out your front sway bar and make sure its not broken or hitting the downpipe.

I know this sounds random, but if its something that may be hitting around the engine, it could trigger the knock sensor. You may have a bad knock sensor as well. I think you can pick them up fairly cheap (around 40 bucks) or you may want to get ahold of Ed Morad and see if he has a used one you can get really cheap just to try it out.

webracin

Originally Posted by Reptile

knock at 6% throttle? no freaking way. that's literally impossible.

Tell that to my car.

I have some more supporting evidence to the "bad gas" theory. I just drove 380 miles home for my small vacation, and before I left I needed to top off. I put in about 4.5 gallons, which means I had about 12.5 gallons of suspected "bad gas". Throughout a lot of my trip, going up a hill it'd start knocking in the 10% TPS range. Halfway during the drive, it got better. I could lean in to the throttle and hold it at 20% TPS without knock. But, later on by the time I arrived (I'm now under a 1/4 tank) just cruising on open flat road at 75 MPH saw occasional random knock. I'm hoping that time that it was doing better was from the newer good gas (93) that I added mixing in and raising the overall octane of the bad gas. But, by the time I got here too much of it was gone... Eh, it's possible. Grasping for straws I guess.

The way I knew it was knocking was my Aeroforce gauge. Didn't want to mess with the tuner during the drive. I set it to cyclic scan and the annunciator lights to go off at 1.5* of knock or more. Needless to say I saw a lot of red lights... When I left it on the knock value, I'd watch it jump straight to about 2-3*, begin recovery and actually make it to zero, then spike again. Sometimes it only spiked less than a degree and was instantly gone.

I'm at a loss.

Originally Posted by webracin

Do you have a aftermarket downpipe?

Yes, a 2.5" from ZZP.

Originally Posted by webracin

Check out your front sway bar and make sure its not broken or hitting the downpipe.

I'll take a look tomorrow.

Originally Posted by webracin

I know this sounds random, but if its something that may be hitting around the engine, it could trigger the knock sensor.

I've suspected that and I've been hunting something loose. The "needle in a hay stack" analogy comes to mind...

Originally Posted by webracin

You may have a bad knock sensor as well. I think you can pick them up fairly cheap (around 40 bucks) or you may want to get ahold of Ed Morad and see if he has a used one you can get really cheap just to try it out.

I've got a hookup with a guy at a GM dealer who gets me parts at cost pricing. I may get two new ones depending on how hard they are to change.

I will definitely be replacing my O2 sensor while I'm here at home (I had my GM guy ship it here for me, it arrives tomorrow). With 67k miles it couldn't hurt. Next if 3800Performance shipped my order the day I placed it (though I got no shipment confirmation) then I'll soon have Poly motor mounts to install which maybe the reduced engine movement will help (assuming it's false knock).

I wanted to do plugs and wires (plugs should arrive soon) but Paul at PRJ is out of town and I will have to wait on his wires until I get back to my base next week. So, plugs will wait until then, too.

If these don't fix it, knock sensors I guess.

I'm loving the ideas, though. Keep 'em coming. I really do hope it's false knock because the idea of my engine knocking that much makes me woozy.

Gotta get to bed. I worked today and drove nearly six hours...

unplug them. :P

I just filled up with a fresh tank and will see how it goes. In the mean time, could loose DP to manifold nuts or a ticking flex cause knock?

Before I filled up today, I was able to get into the throttle fairly aggressively with little knock. It knocks the most when the TCC is locked and I push into the throttle. I'm not sure if the vibrations resonate in a certain way and cause something loose to rattle or what. The DP wasn't installed by me (had to take it to an exhaust shop and get the OEM DP cut out) so I can't be certain of their tightness.

I guess it is real knock then.

Why doesn't it knock when I get into the throttle more and the TCC isn't locked? Like somewhat aggressive acceleration in 2nd gear around town...

Meant to say that I have those TCC tables filled to the max so they should never try to limit me. It's weird that I can get into the throttle and not see hardly any KR (nless I hit PE, that's still f'd up) but I can barely cruise without seeing 1.5-3*.

Been on new gas for a couple days and no change. I'm also pretty sure it's real knock because when the engine is still pretty cool it won't do it. So, something is heating up in there and causing knock.

I've got nearly 68k miles on the factory iridium plugs and I think they're causing knock. New plugs are on the way, and PRJ wires will meet me back home later this week. Tuesday I'm changing my O2 sensor.

So, I'll see what happens. I've successfully eliminated gas as the issue, though I'd hate to see how bad it is with 87 instead of the 91/93 I have been using...

No luck with changing plugs, O2 sensor, and wires. I'm now on AL605s, PRJ wires, and a brand new AC Delco O2 sensor and it's still the same, if not worse.

I went WOT once and saw a solid 8* of KR with 880-890 O2s.

Is the MAF used during WOT or when in PE? It might be suspect. I'm going to unplug it and see if the car acts any better...

Also, would a leaking o-ring on an injector cause some knock? I smelled a little fuel while leaning over the alternator, and looking at the jetting on my #2 plug it may show some lean running. If I had a vacuum leak at the o-ring for that cylinder's injector, it may be explained.