Please look at my log "knock"

[JDR7919]

Hello all,

Please take a look at my log

Mods are:30 over je pistons, Eagle Rods, Balance shafts removed, 3" down pipe 3" gm mass air flow sensor, upgraded fuel pump 255 Lph, 550 injectors, Ported 16g Ported O2 housing, 2g ported exhaust manifold, act 2600, Fidanza Flywheel, 4 bolt, Logger.

This was 1st and 2nd gear
rpms knock 02 volts
1062 0 .75
1937 0 .08
1718 11 .08
3343 9 .69
4968 19 .78
6218 18 .80
4468 0 .68
4625 29 .82
6750 26 .82

My fuel trims ar low 87 Mid 99 High 97

My Maft settings are base 4 idle 4 mid 4 wot 4
I checked my base timing its right at 5*
Does this look like Im lean? I thought in the .80s was good?
Check my knock sensor it looks good no gunk coming out of it.
Running 93 oct

Any thoughs from anyone would be great.

 

[CanadianTSi]

Hello all,



Any thoughs from anyone would be great.

Do a 3rd gear pull from 2.5 to 7k so we can get a clearer view, although from that little tidbit of info it looks like your lean.

 

[scottsee]

intresting, without a afpr i was expecting your 02's to be in the upper .90's. your really lean. what is your base fuel pressure. test that, and do that 3rd grear log he suggested.

 

[JDR7919]

Ok guys here is a log in 3rd gear.


rpms knock timing 02 volts
1718 0 30 .84
1812 22 18 .14
1837 27 16 .78
1968 31 14 .80
2062 30 15 .82
2437 28 12 .86
2718 27 6 .88
3062 25 6 .88
3781 22 9 .88
4531 20 10 .88
5062 18 12 .86
5718 16 16 .86
6250 14 16 .86
6468 17 14 .86
6500 23 10 .86
6781 22 10 .86
6937 21 9 .86

What thoughts would you guys have?
The car seems to pull really hard I was doing almost 100mph does that sound right or should I be going faster.

I also noticed that when i went over some railroad tracks I got 10 counts of knock. So I was wondering sense my car is lowered 2 inches and is really stiff would that cause it to pick up road noise?

Do you guys know of an article that would tell me how to check my fuel pressure?

 

[JDR7919]

Oh yeah Im running 15psi

 

[CanadianTSi]

Your knocking because your lean, which is killing your timing. Add some fuel and do another log, tune for 0 knock.

 

[JDR7919]

Ok where do i add the fuel low mid or wot?

 

[94Jettameowpsst]

not to hijack your thread, but when your doing a pull in 3rd and you get upwards of 20 counts of knock, shouldnt you let off? Isnt that real bad for your engine, im still kinda confused on that. I mean i dont see any other way besides trial and error if you let off, but i thought you would seriously hurt ur sheet if you kept on it

 

[CanadianTSi]

Ok where do i add the fuel low mid or wot?

WTF

WOT...........

 

[GVR4592]

If you are knocking from driving over railroad tracks that should be the first thing you need to fix. I would take a look at the balljoints. Now if you are knocking even a little bit (real knock, not railroad track knock) it's very bad for your engine.

Are you just using the maft for tuning or do you have an safc also? I'm not very familiar with the maft but bascially anywhere you are knocking you need to add fuel. From the looks of your 02's and the knock count you are pretty lean. Your goal should be 0 knock at all rpms with good timing advance and good 02 readings. It's always better to start a little rich and lean it out, instead of starting lean and trying to richen it up and damaging your engine in the process.

What spark plugs are you using? What is your base timing? For your fuel pressure you need a gauge and a afpr. If you dont have them then you can't tune your car properly.

 

[JDR7919]

Ok so I changed my fuel filter and increased fuel my o2 volts are staying around .70 to .86 that would mean Im still lean right? Im confused because now that I have increased the fuel the car cuts out and pops. 1st does not pull as cause it cutting out and when I get to second and third it starts pulling.

Im using ngk plugs.

What is a good afpr to get that wont kill the wallet?

 

[JDR7919]

Ok one more question.
I have been adjusting my setting on the maft.
According to the instructions for 550 injectors my base setting should be set to # 4 which would make it -20% well I changed to #3 which makes the base setting -15% for 525 injectors. Now my o2s are better and the car is pulling better, does this make sense to anyone?

I do have some knock still but not as high as it was! Should I drive the car like it is for a few days and see if it levels out?

If it stays should I leave my base setting at 3 or change it back

 

[CanadianTSi]

Makes perfect sense...you were lean, you added more fuel so now your not as lean thus not knocking as much and get more timing...this is how tuning works.

 

[GVR4592]

You are relying on your O2 way too much. Forget about the O2 for now, they never read the same from vehicle to vehicle so saying that its .86 doesnt mean anything. You want to tune for 0 knock. If you are knocking richen it up a LOT. Then start leaning it out slowly until you get the desired results. It's better to start rich then to start lean.

 

[4G63 GST]

Ok guys here is a log in 3rd gear.


rpms knock timing 02 volts
1718 0 30 .84
1812 22 18 .14
1837 27 16 .78
1968 31 14 .80
2062 30 15 .82
2437 28 12 .86
2718 27 6 .88
3062 25 6 .88
3781 22 9 .88
4531 20 10 .88
5062 18 12 .86
5718 16 16 .86
6250 14 16 .86
6468 17 14 .86
6500 23 10 .86
6781 22 10 .86
6937 21 9 .86

Whats getting me .. is the 1800 rpm O2 reading .. a .14 .. now maybe it was that the car wasnt at WOT but if it was that reading doesnt make sense to me. At idle most O2 sensors will fluctuate between .2ish and .8ish trying to keep a 14.7 to 1 af mixture which is obviously impossible .. im just curious why it would dip from a .8 to a .1 if indeed it was at WOT

Seems that the car is running rich as the log appears.. a .8 o2 reading is really rich

 

[CanadianTSi]

.8 is not rich....most 1g's like it around .88-.90ish althought they all vary, also you can tell it's too lean from all the knock.

 

[4G63 GST]

a .8 reading from an 02 sensor is definatly rich .. and will definatly shorten the injector pulse (which trys to lean it out to correct the a/f) .. now the car may be knocking .. but a .8 reading from an 02 sensor is a rich reading ..

 

[CanadianTSi]

but a .8 reading from an 02 sensor is a rich reading ..

Where did you find this Information??

Also what is your o2 voltage under WOT because I know on my car anything under .94 is too lean and starts knocking...

 

[GVR4592]

.8 is lean.....LEAN. not rich. canadiantsi is right .94 is a good ROUGH area to have your o2 readings at wot. But with your knock being as high as it is you are destroying your engine. Seriously man I'm not blowing smoke up your ass. Do some searching I am right. DO NOT continue to drive your car with that much knock. Richen it up a lot. Make sure you have the correct plugs and they are gapped correctly. If you dont believe what I'm saying I'll pm you a log of my car with a big16g @21 psi with 0 knock 20-22 degrees of timing advance, .94-.96 O2 readings and 11.2-11.7 a/f on 92 octane. If your engine is knocking at all it is seriously damaging your engine. If you are trying to get 14.7 a/f at wot your engine is not going to last another week. Optimal a/f for a turbocharged car is around 12.2:1. You can make it richer than that to help cool the a/f charge, but definately dont go any leaner than that.

 

[4G63 GST]

Ok .. let me justify what i am saying ..

.8 is rich as apposed to .2 .. im not arguing that .8 at a WOT position is rich (if thats what you thought im sorry i was confused)

Im stating that .8 would be a rich reading from an o2 sensor sitting in closed loop at idle..

If your at WOT and your running a .8 its still a richer reading but could be lean under the circumstances of his knock. On another car a .8 could be a rich reading and be fine .. but on his vehicle you would want to richen it up even more .. because it is STILL too lean .. correct?

 

[JDR7919]

Ok I think Im on the right track now I have gotten my o2s around .84 and .94.

When crusing at say 65 how much should the o2 go up and down?

Also my EGTs are about 1250 at 65mph does that sould ok. Will that go down when I get my fmic?

Thanks for the help guys I will keep you posted

 

[spyderturbo007]

a .8 reading from an 02 sensor is definatly rich .. and will definatly shorten the injector pulse (which trys to lean it out to correct the a/f) .. now the car may be knocking .. but a .8 reading from an 02 sensor is a rich reading ..

Yes 0.8 is rich compared to 0.2, 0.2 is rich compared to 0.1 but who cares.

You don't tell someone who is getting 20+ counts of knock and a 0.8V O2 reading that they are running rich

Also, at WOT the ECU does NOT use feedback from the O2 sensor, so saying the IPW will be shortened because of the O2 voltage is bullshit. At WOT the ECU is in open loop and really only cares about mass airflow (barometric pressure, flow speed and intake air temperature).

Please you either need to choose your words a little better so you don't confuse someone or you need to do more research. Either way, watch the misinformation

 

[spyderturbo007]

When crusing at say 65 how much should the o2 go up and down?

At idle or cruise you should see the O2 voltage fluctuate above and below 0.5 which is considered the stiochometric point for the air/fuel mixture. It really doesn't matter what the range is as far as watching the numbers and trying to determine if it working correctly. As long as they are cycling and your FT's are around 100% (1g) and 0% (2g) you will be fine.

 

[JDR7919]

Ok so I take my car for a ride today and it does the really weird thing. When I start out in 1st gear really slow im mean going like 5 mph my logger says I have 255 counts of knock.
Now I know it only reads up to 43 so what is this 255 about.

I'm also getting knock now when crusing at any speed and slowly accelerate anywhere from 4 to 20 counts. But, If accelerate fast the knock goes to about 15 and begins to drop.

My o2 were going anywhere from .65-.96

The car now dies when I push the clutch in when coming to a stop if I dont let the rpms drop to about 2000 before I push the clutch.

Do any of you feel like these cars are a love hate relationship?
I have been trying to get this thing running good for months now.

 

[xxREVERBxx]

Have you checked your knock sensor? I was geting knock reading of 43 and changed out the knock sensor. Went to about 25 counts of knock, but it was rich knock. I mean you could tell car would chug away in every gear sounded like a steam train.