looking for some help, getting constant 4* KR, at 19* WOT
08-09-2005, 08:33 PM
#1
looking for some help, getting constant 4* KR, at 19* WOT im helping a member on here tune via email and his car was getting better but so much timing has to be pulled, some of the knock starts to go away as you pull it but he reloaded the last tune that was good and said it was like **** this time. what factors can be looked at for this persistant knock problem. the timing had in spots, where it always showed 4* kr, 12-15 deg of timing pulled, and still showed kr. he checked for oil in the intake and had none, consumes no oil. he has a 383, 11.8:1 CR, 236/239 cam, and your normal bolt ons. attached is a screen shot of the max KR and the timing tables. also, wot o2s read 940 mv, dont have wideband so thats the best i can do there. and the fuel trims are zeroed out wot.
08-09-2005, 09:28 PM
#4
what are his part throttle LTFT's? Thats pretty severe knock. I've seen some highly modded untuned cars respond somewhat like that at part throttle. Its possible his knock sensors are dead, o2's are dead, nothing says its really rich at wot even though its reading 940mv.
Have the VE, PE and MAF tables been edited. If not i'd say its in need of a really good tune assuming all sensors are working correctly.
Have the VE, PE and MAF tables been edited. If not i'd say its in need of a really good tune assuming all sensors are working correctly.
08-09-2005, 09:42 PM
#5
yeah man this is the 17th tune i have done for him trying to fix it, the ve is withing -2 to +2 range. he said the o2s are brand new a few months ago. they are oscillating fairly well, the more i start to think about it hte more i think the knock sensors could be bad, but then again its sparatic, i would think it would pull the same amount of timing every time. maf is off right now its got an sd tune in it. pe has been adjusted but left slightly on the rich side. pe enable has also been tinkered with. it is a little better than it was when he first sent me an email but its still a rediculous amount of knock to be getting.
only other thing i can think of it valve train noise setting them off
only other thing i can think of it valve train noise setting them off
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08-09-2005, 09:51 PM
#8
the ve was just tuned the hottest day of the year, and the numbers still look great. i agree he needs to get a wideband on there to eliminate some issues, but getting the money and getting one or finding someone can be hard lol. part throttle o2 oscillation is great though, although there are some sharp dips at times in the readings.
08-09-2005, 09:55 PM
#10
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940 is very rich for an NA engine when I get that high I see smoke at wot and kr becuase of excess fuel I would try and get it down to at least 900-890 mv. Since Im tuning with narrow bands I try and get my trims slightly negative as map increases like -2/3 range above 55 this has helped me keep kr problems down even with the converter locked.
what do the trims look like?
what do the trims look like?
08-09-2005, 09:58 PM
#11
georgia.
trims are all good, ill get a screen shot but its not really worth it, they are all in the +2 / -2 range. he may be rich at WOT but that still wont tell why part throttle would have all that timing pulled when this is during normal o2s operation/oscillation. so pe shouldnt be a factor and the trims are saying its ok. a wideband would be nice to just rule soem things out
trims are all good, ill get a screen shot but its not really worth it, they are all in the +2 / -2 range. he may be rich at WOT but that still wont tell why part throttle would have all that timing pulled when this is during normal o2s operation/oscillation. so pe shouldnt be a factor and the trims are saying its ok. a wideband would be nice to just rule soem things out
