Guy's I'm getting 3-6 degrees of retard from 4800 to 6000
108-112 g/sec, timing is already 15-17 degrees
Any ideas???
most engines run 23-27 degrees around the same RPM and g/sec, WHY??
thanks for your help!!
check your exhaust and make sure you have 1/4 inch of clearance from the body, any contact will transmit vibrations back to the engine and it will pull timing (False KNOCK),, also make sure your motor mounts aren't worn out, causing the exhaust to move excessively.
if your running N/A thats deff low timing, pull another 6-7 degrees and add another .5 point of fuel,, if its still knocking then its 99% false. try and adjusting the knock sensor values.
Or instead you can put some 110 octane in it and see if it goes away.
p.s. i just recently purchased HPTuners Pro and in the process of reading all of their stickies on the forum. ive never touched the program and am just regurgitating info i read there.
Did you check your A/F ratio at WOT with a WB02 sensor installed?
If it was running lean, it will knock.
I did, I have a permanent WB and my AFR are 12.6@WOT, LTFT's are great.
I have gradually backed up my timing from 23 to 17 degrees and Kr still
shows up from 3 gear and up.
put my car on the 4 post lift and cranked it up, put it in gear and
held the rpm at 1400, I looked for anything close that could contact
nothing found, all my scans show something from 4400 to 6000 and
no Kr from 6000 to 7000, and timing above 6200 goes up to 26-28.
Even though I did not see any contact on the exh I still believe that
something is making contact with the frame or trans.
thanks for your replies!!!
Location: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Is there any change if you change your PE table to, say, 11.5:1 to determine if it is fuel related. I noticed if the PE was too lean, I would a few degrees of KR at peak torque in the 4800-5200 rpm. If there is no change, that would seem to indicate it may be burst knock or something banging on the exhaust system.
Also, you may want to check the plugs and make sure all are gapped at .040 and there are no vacuum leaks.
I did, I have a permanent WB and my AFR are 12.6@WOT, LTFT's are great.
I have gradually backed up my timing from 23 to 17 degrees and Kr still
shows up from 3 gear and up.
put my car on the 4 post lift and cranked it up, put it in gear and
held the rpm at 1400, I looked for anything close that could contact
nothing found, all my scans show something from 4400 to 6000 and
no Kr from 6000 to 7000, and timing above 6200 goes up to 26-28.
Even though I did not see any contact on the exh I still believe that
something is making contact with the frame or trans.
thanks for your replies!!!
Is your gas E-10, [10% ethanol] ? If so you need to adj your WOT af ratios by 4% [ 3.9 to be exact], richer. I went through this same problem, in my case it was a lean issue. With a 100% gasoline blend, 12.6 afr on your gauge is 12.6 . With E-10 , 12.6 on your gauge runs like 13.1, that is to the engine , it is 13.1. With E-10 , if you want your engine to see 12.6, you must adj. your WOT afr to read 12.1 on your gauge. If you have access to non ethanol gas , try it . if that fixes your problem then you'll know.
Is your gas E-10, [10% ethanol] ? If so you need to adj your WOT af ratios by 4% [ 3.9 to be exact], richer. I went through this same problem, in my case it was a lean issue. With a 100% gasoline blend, 12.6 afr on your gauge is 12.6 . With E-10 , 12.6 on your gauge runs like 13.1, that is to the engine , it is 13.1. With E-10 , if you want your engine to see 12.6, you must adj. your WOT afr to read 12.1 on your gauge. If you have access to non ethanol gas , try it . if that fixes your problem then you'll know.
Location: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Quote:
Originally Posted by REVAK
Is your gas E-10, [10% ethanol] ? If so you need to adj your WOT af ratios by 4% [ 3.9 to be exact], richer. I went through this same problem, in my case it was a lean issue. With a 100% gasoline blend, 12.6 afr on your gauge is 12.6 . With E-10 , 12.6 on your gauge runs like 13.1, that is to the engine , it is 13.1. With E-10 , if you want your engine to see 12.6, you must adj. your WOT afr to read 12.1 on your gauge. If you have access to non ethanol gas , try it . if that fixes your problem then you'll know.
What year is your car? My 2005 PCM does not measure the % ethanol in the fuel when calculating AFR but the newer ones do. I forget which year this feature was added, but if you do some research, yours may already take that into account.
What year is your car? My 2005 PCM does not measure the % ethanol in the fuel when calculating AFR but the newer ones do. I forget which year this feature was added, but if you do some research, yours may already take that into account.
Mine is an 06, I don't think my car has that feature. When I set my scanner to read % eth. , there is no data value. We've had the crap 10% eth. gas for nearly 2 years now here in eastern Pa. Thanks for the info about eth. compensating feature, I did not know they addressed that. It does tell us though, it is a legitimate problem , or they would not have bothered with it.
guys, I added 110 octane fuel 5gals to 1/4 tank of 93 and it made no diff on my
Kr.
Christopher suggested to unplug the pass side Knock sensor and do a scan and see if anything diff happens, follow up with unplugging the drivers side and repeat scan.
I will try that sat!!
We agree that something is rubbing is causing the Kr (mechanical)??
Location: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Quote:
Originally Posted by pmj341
guys, I added 110 octane fuel 5gals to 1/4 tank of 93 and it made no diff on my
Kr.
Christopher suggested to unplug the pass side Knock sensor and do a scan and see if anything diff happens, follow up with unplugging the drivers side and repeat scan.
I will try that sat!!
We agree that something is rubbing is causing the Kr (mechanical)??
Well, I believe I found the problem.
I removed the plug from the RH Knock sensor and did a scan from 1st thru 4th, no knock retard at all.
Christopher Martin had the same problem, he told me to try it, and it worked!!
the problem was the header making contact with the frame, I had clearance issues after installing the headers, so I removed some material and got 1/4" clearance, I was sure that was enough, but under full throttle the engine moves enough to hit, 1/4" is not Enough you need more.
I will figure a way to get more room.
Location: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Quote:
Originally Posted by pmj341
Well, I believe I found the problem.
I removed the plug from the RH Knock sensor and did a scan from 1st thru 4th, no knock retard at all.
Christopher Martin had the same problem, he told me to try it, and it worked!!
the problem was the header making contact with the frame, I had clearance issues after installing the headers, so I removed some material and got 1/4" clearance, I was sure that was enough, but under full throttle the engine moves enough to hit, 1/4" is not Enough you need more.
I will figure a way to get more room.
Hey, Joe!!
I wonder why most AR headers have this problem??
I've been wanting to go, I would have to go early to avoid the Rain!!
now I will be able to bump my timing up to were it should be, maybe it will help my MPH.
How early are you going??
Hey, Joe!!
I wonder why most AR headers have this problem??
I've been wanting to go, I would have to go early to avoid the Rain!!
now I will be able to bump my timing up to were it should be, maybe it will help my MPH.
How early are you going??
Sounds like their jig needs to be adjusted a bit. I had one of the first sets so I figured it was a birthing pain. Guess not!
You will get your 10 second slip for sure next Sat.
I can't get there that early due to family commitments. Evenings are much better for me. Plus it's so darn hot in the sun all day. Gates open at 8 and track is hot at 10 am.
Corvette Store
Kr- timing only 15 degrees
