What are you thinking Corey? I put all the stock stuff back on and sold the Dynas.

 

Well i am thinking of 2 things....

You have a high compression lq4 right? that high compression mixed with a stock cam is not the most efficient engine... I think that the lack of exhaust is building up heat inside the combustion chamber, thus causing the KR after a little bit... Are you still running cats???? See what i am getting at... I bet if you unbolted the y-pipe muffler back would be a nice test...

The other idea is the your fuel pump is not providing enough gas or the tune is off (try adding 10% to the MAF table starting at 8000 and up)... Have you put a mechanical fuel pressure gauge on the truck? The reason i am thinking this is because if you look at the WOT runs in the i believe there is several different WOT punches, the last one got KR... If you watch the O2 voltages of each of the runs they gradually get less and less and less.. Finally on the last WOT punch the O2s go to 870-880, then bam KR....

 

I've still got the cats on. But I dont think that is contributing, because I've always had low numbers at the dyno which I now contribute to the KR (but I can't confirm because I didn't have the logging software back then). I also didn't have the logging software when I had headers and no cats.

Regarding the fuel pump, I just can't fathom it being weak. It was a brand new OEM unit put in back in March of this year.

 

Anything is poss when it comes to fuel pumps.. I see what he is saying.. You really should put a FP gauge on there, even a AFR.. That would tell you real fast if your dropping FP..

 

Ok then how do you explain the O2 readings reading around the 870-880 when your comanding 12.0?????????

 

ive seen 2 brand new OEM pumps be dead or low pressure... then the third one was good... pretty screwed up if you ask me.

 

Just as a test go multiple your MAF table (B5001) starting in cells 8000Hz and up by 10-15%....


Or

Instead of buying a catch can and other crap go buy a wideband... They are 159 shipped on ebay for a LC1...

 

Because this isn't a LQ4 engine. It's a LQ9 with ported heads and higher compression running on a modified LQ4 tune. It's possible that the fueling is off, but I find this highly unlikely because I've had KR on those logs when the o2s are reading above .900mV

 

Just as a test go multiple your MAF table (B5001) starting in cells 8000Hz and up by 10-15%....


Or

Instead of buying a catch can and other crap go buy a wideband... They are 159 shipped on ebay for a LC1...

 

No I actually want the catchcan. The though of oil inside my new intake and heads sickens me.