Greetings,

Over the weekend, I did a couple autotap run's. I still have Knock Retard (as high as 4 and 5). My o2 sensors (while WOT) was over 0.9. Does this mean I am running rich or lean??? What are other indicators that may attribute KR?

Thanks!

 

If you had a MAFT installed, you could try richer settings to see if that made the KR go away. If it did, you might be running lean. You can still run lean with O2's over .9. I don't think the stock O2 sensors are accurate enough to go by those readings alone.

Mike

 

What's your Air/Fuel Ratio?

 

I was just researching this last week.
Here's one of the best pages, titled, "The Causes of Internal Engine Knock, and How to Eliminate it."
http://zhome.com/ZCMnL/PICS/detonation/detonation.html

My Vinci fan controller arrived last week.
I'm having Speedworks install my 160* thermostat and fan controller sometime hopefully later this week after Frank Parra installs my other major mods (as part of a package deal with my 2002).
I dynoed my car again last week and I witnessed a 3 hp decrease and 2.6 decrease in torque compared with the numbers seen in my sig obtained the week before. The engine was running quite hot and the air temperature was 10* higher than when I did my dyno the previous week. Running 93 octane in both instances. ~200 miles difference between dyno days. There was slight knock/detonation occuring between 5000 and 5500 RPM.

I'm going to dyno again after ALL the mods are in place.

I'm hoping that the Blackwing, cold air screens, throttle body coolant bypass, throttle body performance coupler, 160* stat, and fan controller should all help reduce or eliminate the detonation.

 

Autotap is the way to know.

But to your original question, some of us are old enough to remember the smell of lean and rich.

 

Is Air/Fuel mixture one of the parameters within Autotap? I have many autotap runs. I'd be happy to share the file to get your interpretation. Any other suggestions?

Thanks


[Modified by sbkim, 4:40 PM 9/10/2001]

 

Here's a link to various autotap runs from the past:
http://briefcase.yahoo.com/bc/sbkim/...c=bc%26.view=l

THanks

 

:D :D :D :D :D :D :D :D :D :D :D :D :D :D :D
With your quest on KR,I'm having second thoughts for you to bring the Autotap when you come to Chi-town and test it on my car on Sunday,September 23 :jester Just kidding :cheers:

 

I'm no expert, but from the looks of your autotap logs you're running a little rich. :nono:

 

Exactly! All my runs indicate that my car is running rich! So why in the hell am I getting KR!!!! I'v checked around for anything that may cause rattle but nothing yet. So, may be I just have a bad knock sensor??

TC -- I can't wait to log you Autotap log that is ;) Or would your prefer a different log :lol: ok, now we are getting out of control :conehead

 

What data in your scans indicates that it is running rich? Mine runs too lean with the O2's lower than about .92 so you really can't tell just by looking at the O2's.

Mike

 

mchaney,

look at the LTFT'S.

I'm running the same way, about 5% rich.


[Modified by RPOZ4Z, 8:40 PM 9/10/2001]

 

Wadaaaaaa SBDiddy- Can't wait til you bring Autotap next weekend to ra-ta-tap-tap my car :cool: I'm already prepared for KR and see you laugh your head off in the background when I do get KR :lol: :lol: :lol: :mad BTW, how's the house coming along in Kansas City?
Seeya in a few :cheers:

 

Tom,

Yes, I am fired up myself for the visit. I am just hoping that my conference won't be canceled due to recent tragedy in the East. Bulk of the participants are from the East coast.

I will keep you posted. The house is great. If you can believe this, I have been working on the lawn for the last month or so and various home improvement projects --aka mods for the house

Later

 

sbkim,

Among the other suggestions......we used to "read" the spark plugs to get a handle on the "rich/lean" question.

If you suspect a knock sensor.....they are susceptible to over torquing. Sensitivity increases with increased torque.

Have you decarboned the engine?

Good luck.
Mark

 

sbkim,

I just looked at your AUTOTPs.

O2s are most 0,89.

Thats´s on the LEAN side.

I run at 0,92-0,94 NA and 0,94 on NOS (little rich for afety issues)

<0,90 on the lean side
>0,90 on the rich side

To perfect tune NA most Vettes wanna see 0,89 for best hp (but it´s not easy to get that without NR)

To be safe especially on NOS most wanna see 0,94 on the O2s.

That´s what I found about that theme:

WOT O2 averages:
The WOT O2 average is calculated from the B1S1 and B2S1 O2 sensors while under WOT. I have defined WOT as a TPS (Throttle Position Sensor) value above 99.5. Typically, when I go WOT, Tap indicates TPS of 99.6 or 100. This reading, which indicates voltage, can be correlated to an A/F ratio. For MY car (as calibrated by comparing my O2 readings to a wideband O2 sensor) I achieve a 12.5:1 A/F ratio when my O2’s indicate 0.900. It is generally accepted that you want your naturally aspirated (NA) WOT O2’s to be between 0.875 – 0.910. Since I’ve calibrated my O2 readings to a wideband O2 sensor, I know that I want my WOT O2 average to be right at 0.89 to achieve the ideal A/F ratio of 12.5:1 – 12.7:1. A higher voltage (0.93…) indicates a rich condition and lower voltage readings (below 0.875) indicate a lean condition.


All that I don´t understand is that your LTFT show little rich and
the 02s show little lean????


Maybe a pro can tell us more?????


Michael
Michael




[Modified by Austrian Vette, 7:55 PM 9/16/2001]

 

Do you still have the stock plugs in? I had the same problem and found 3 of the platinums had the lower puc missing. Got TS55 plugs & the problem went away.

 

Possibly C4C5 Tech can help you?

 

Mark,

Thank you for your insight. No, I have yet to decarb the engine. I will try that once I narrow down my problem. i have a hunch that it's my powerloader causing this problem. I am really leaning to MAFT...

Michael,

Thank you so much for the info. Yes, I have been getting similar comments from the "pro's". I want to say LTFT was changed by Steve Cole to run on the rich side -- just a speculation. Lean WOT is beyond me. I thought I was running rich under WOT as well since some of my readings were 0.91x under WOT? I was told by a forum member to start logging additional items such as fuel injector pulse and etc. I will keep you guys posted.

Thanks!

 

SB...sounds good and understandable after everything that happened last week. :mad Just give me an update later this week. BTW, speaking of house mods, did you mod your weedwacker yet? :p: