Thread: Kr kr kr and more kr

I swapped in my l67 a couple months ago and forgive me if this is a little lengthy but I have been through it alot with this thing and still cant get the kr under control so I am looking for advice. At wide open throttle the knock on my car is up to 8 or so and I have already changed a bunch of stuff. The long term fuel trim and short term are consistantly lean and I have changed the fuel pump, filter, pressure regulator and I have checked the injectors for leaks. I have a small exhaust leak on the front header that I havnt had an opportunity to fix yet but I have also replaced the o2 sensor as the rear one has been deleted in the tune. I always run 93 in it and the mods are as follows Intense tuned pcm, prj wires, ported supercharger, zzp stage 1 tb with 99 maf, tog headers w 3" dp, 3.4 mps, ram air hood and box, al 104s. If you guys have any insight on why my setup might be pulling up to 8 deg of kr at wot I would be more than greatful.

sounds like your tunes chitty. A scan would help

I have an ls1 scanner thats why am able to decipher some tuning the long /short fuel trims are lean but what could cause this? I have checked the injectors, filter, regulator I have also replaced the supercharger twice (first one had jb weld come loose and lock up rotors, second one was chit). I had a 98 tb on it by mistake but I changed it out for a zzp stage 1 with the 99 maf it is supposed to have. I added a new m90 today checked all the torque specs on the lim sealed the coolant ports and put new o rings on all the injectors. I have a 255 lph fuel pump and I am about to throw 80 more bucks at by ordering the fuel pump hotwire kit. I have thought about trying 103s but I cant see needing them with just a 3.4 pulley?

Crappy tune...or...hows the mounts in that thing? Sway bar hitting the downpipe? o2 Sensor hitting the firewall or something...just trying to rule out false knock situations.

does the trims ever hit 16.4?

Might be that ported TB with the canned tune. Time to invest in a tuner or go have someone do a custom tune on it.

Originally Posted by bluegtp91

Crappy tune...or...hows the mounts in that thing? Sway bar hitting the downpipe? o2 Sensor hitting the firewall or something...just trying to rule out false knock situations.

All the mounts and the o2 are new it only knocks at wot.

Originally Posted by 01gpgt01

does the trims ever hit 16.4?

the ltft used to be at 16.4 but now it bounces around at 8 to 0.

16.4 would indicate a vac leak. Post some scans from the LS1m

Originally Posted by DanGTP

Might be that ported TB with the canned tune. Time to invest in a tuner or go have someone do a custom tune on it.

I am sure it prob is the tume but thats why i paid 170 for unlimited tune mods. I have a local guy who has hp tuners guess thats my next step besides the fuel pump and hot wire.

Originally Posted by SnowFlake

If you had a way of loading your tune with a DHP I could fix up your BIN file for you. Your problem is definitely in the tune.

sent you a pm but what could be wrong with the bin? he did set the tune up for 1.9 rrockers that i havnt added yet could that be whats causing it?

You say you have an exhaust leak on the front manifold. Fix it. Between possibly blowing noise at the knock sensor and pulling in air that will show your exhaust as lean... this could easily be causing KR.

ZZP S1 TB. Was this tuned for? Many times I see these without a maf screen. That could easily cause a lean condition. If this wasn't tuned for, then likely it's helping cause KR.

Originally Posted by darkhorizon

99/100 times I see this its not tune related.

You've seen this problem a hundred times?? What do you suppose is causing his issue, then?

Originally Posted by SnowFlake

This guy hasn't seen 100 L67 powered cars pass him on the highway, nevermind see this problem 100 times.

Pending further info from the OP I'm saying it's tune related. Of course he could circumvent the tuner's faults by getting a bigger pulley and installing the 1.9's.

The 1.9s are a ways down the road but i did pull the front header off today and it had a huge leak in the center of the collector and i have brian coming down on sat with his hp tuner to look at the tune and see wher im at hopefully we can get it ironed out. I got the walbro pump and tried to install it in my gt fuel pump housing and it wont fit hope the gtp one is different.

Originally Posted by SnowFlake

This guy hasn't seen 100 L67 powered cars pass him on the highway, nevermind see this problem 100 times.

Pending further info from the OP I'm saying it's tune related. Of course he could circumvent the tuner's faults by getting a bigger pulley and installing the 1.9's.

i hope youre not serious because dude has seen more 3800 action this year than you ever will. he knows what he is talking about and you do not.

Well I got the exhaust leak fixed and installed the 255 lph fuel pump (what a pain ) and now the long and short term fuel trims are bouncing all over the place lean to rich and sometimes it knocks when barely into boost and sometimes it will knock like hell up to 10 deg +. I really need help on this guys some are saying its in the tune and some arnt. the fuel pressure goes up to 55 at the rail when you turn the key on and dreps to 43 at idle when you get on the gas it comes back up between 52 - 55. the exhaust leaks are gone and the temp runs steady at about 180 unless its really hot outside. I am going to change the fuel filter again tommorow and might throw a new set of plugs in it.