Knock Retard Problem? Need some expert advice.
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Knock Retard Problem? Need some expert advice. I recently installed TEA 5.3L heads milled .015, which raised the CR to 11:1. I am now getting random part throttle knock retard ranging from 1 to 5 deg. I am getting very infrequent KR at WOT with .5 to 3 deg. I know how to get rid of the WOT KR...just need to play around with the timing for the new setup. But am stumped about the PT KR. Is this normal? Did not have it before the head swap.
Re: Knock Retard Problem? Need some expert advice. I think that it might be normal. I had my 5.3 heads ported and also had KR at part throttle, I have a truck though. I asked about this in the truck section and was told that it was more than likley false knock. In your WOT runs, do you have KR throughout the entire run or does it come down to zero KR? Mine would start at about 8* and wind down to 0*KR within about 4-6 sec. Hope this helps ease your concern.
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Re: Knock Retard Problem? Need some expert advice. The WOT KR is very rare and random. Very small amount also. I will be base lining the WOT timing at 25 deg and massage it based on the dyno results. I do have a new exhaust also, but installed very tight and no rattles. Any other ideas on the PT KR?
TIA
TIA
Re: Knock Retard Problem? Need some expert advice. I'm not an expert, but I don't see how KR affects your driving at part throttle. See how everything goes after your tuning otherwise sorry, don't know what to tell you.
Re: Knock Retard Problem? Need some expert advice. If you raised the compression of your motor, you may have to retard timing slightly at part-throttle to get rid of the KR.
Having KR at part-throttle is the best thing for the motor, but as long as your KR is functioning properly, your PCM will do its best to keep detonation to a minimum.
One problem that you may want to consider is that without some timing table modifications, your car may kick to the Low Octane Table. This will lower both your part-throttle and WOT timing. The car will run slower on the Low Octane Table, until you put 5 gallons of gas in it.
Good Luck,
Kevin
Having KR at part-throttle is the best thing for the motor, but as long as your KR is functioning properly, your PCM will do its best to keep detonation to a minimum.
One problem that you may want to consider is that without some timing table modifications, your car may kick to the Low Octane Table. This will lower both your part-throttle and WOT timing. The car will run slower on the Low Octane Table, until you put 5 gallons of gas in it.
Good Luck,
Kevin
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From: Overland Park, KS, USA
Re: Knock Retard Problem? Need some expert advice. Thanks Kevin for the input. I have not looked at the PT timing tables. I always see the values all over the place and did not know you can set them. I will talk to Mark at RMS about it. I see most of the KR at low rpm and mph, or basically from stop. Probably occasional clutch chatter and with the torque strap it is causing the KR? The other occurrances are in the 4000 to 5500 rpm range at PT, which is in fact a timing issue with the higher compression.
Thanks again,
Randy
Thanks again,
Randy
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Re: Knock Retard Problem? Need some expert advice. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong> If you raised the compression of your motor, you may have to retard timing slightly at part-throttle to get rid of the KR.
Having KR at part-throttle is the best thing for the motor, but as long as your KR is functioning properly, your PCM will do its best to keep detonation to a minimum.
One problem that you may want to consider is that without some timing table modifications, your car may kick to the Low Octane Table. This will lower both your part-throttle and WOT timing. The car will run slower on the Low Octane Table, until you put 5 gallons of gas in it.
Good Luck,
Kevin </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I am interested in this. I have heard that about the low gas going to the low octane tables. Is there anything I can read to see this?
I don't believe this is the case with my 2000 truck,as I have compared Autotap reads and paid attention to timing and KR, and not seen a difference between full of gas, and almost out. Very interesting though. Thanks in advance! Sam
<strong> If you raised the compression of your motor, you may have to retard timing slightly at part-throttle to get rid of the KR.
Having KR at part-throttle is the best thing for the motor, but as long as your KR is functioning properly, your PCM will do its best to keep detonation to a minimum.
One problem that you may want to consider is that without some timing table modifications, your car may kick to the Low Octane Table. This will lower both your part-throttle and WOT timing. The car will run slower on the Low Octane Table, until you put 5 gallons of gas in it.
Good Luck,
Kevin </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I am interested in this. I have heard that about the low gas going to the low octane tables. Is there anything I can read to see this?
I don't believe this is the case with my 2000 truck,as I have compared Autotap reads and paid attention to timing and KR, and not seen a difference between full of gas, and almost out. Very interesting though. Thanks in advance! Sam
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Verdad Gallardo Re: Knock Retard Problem? Need some expert advice. Your car goes to the low octane table when it determines (due to excessive KR) that there is a poor tank of gas in the car.
The PCM resets this safety function when 5+ gallons of gas are put into the car.
Your gas level does not effect timing unless you have already been kicked to the Low Octane Table, and your car is just waiting for some better gas to get put in before it goes back to the normal High Octane table.
Good Luck,
Kevin
The PCM resets this safety function when 5+ gallons of gas are put into the car.
Your gas level does not effect timing unless you have already been kicked to the Low Octane Table, and your car is just waiting for some better gas to get put in before it goes back to the normal High Octane table.
Good Luck,
Kevin
Re: Knock Retard Problem? Need some expert advice. I am having a similar issue. I can hear spark knock if I blip the throttle in neutral and at throttle tip in on the highway.