No changes I have made helped. I changed all of my spark plugs with new tr55's. my old plugs looked GREAT. I also bought a set of new coils to try out.
One thing someone mentioned is a crank relearn. I have never done one, my truck has had at least 5 pcms in it, and 1 engine swap. But I've never thrown a code or anything related to a crank relearn. Could that be somehow causing this? I'm baffled.
Then in that situation I'd without a doubt be doing one asap.Originally Posted by GMCtrk
Any fuel pressure check[s] been made?
Chuck L.
CODY Motorsports
Fuel Injector Service
Madison, GA.
706-342-3152
770-265-5144 [C]
No, but I have recently put in a brand new OEM fuel pump
Lower your PE mode from 90% throttle and disable cat protection
Suggest you..
check it to see if it's maintaining PSI @WOT....
Chuck L.
CODY Motorsports
Fuel Injector Service
Madison, GA.
706-342-3152
770-265-5144 [C]
did you add more fuel as i suggested? you were not very far off from the first tweak i suggested to you. trust me kr will go away once you reach that magic .915mv or so. your tuner took out way too much timing. if you noticed the kr almost went away when you added 2.5 to the ve and 15 to the maf but it was too much and too little timing giving you a very inefficient burn, hence you had some minor kr. in n/a configuration, it will be very hard to hurt the motor as long as you maintain a conservative timing curve of not more than 22 on your wot runs. if you are worried about kr ruining the motor than why don't you just do 6 and 6 for the ve and maf tables respectively and work your way down.
04 gto 243 gmpp cnc ported heads , hot cam 219/228 .525 112, kooks 1 7/8 l/t,lm-1wb, sending unit for fuel press. logging, drag bags for the track na 12.2@112mph 1.77 60ft. new add ons 42lbs lucas injectors, lpe walboro, daves wet plate kit, purge,heater, fpss, wot sw., fjo mini controller,nano, new p/b on hoosier 275/40/17 10.998@126.49mph,1.588 on 103vp, 18* timing 11.2 afr. n150w bassani catbk. catless with ls7clutch.
Bump for OP.
What is the stock compression ratio.
Now with milled/ported heads your compression ratio is 10.6...?
Do you have pics of the ported heads...?
From log posted below, KR shows sawtooth pattern:
Last edited by joecar; June 13th, 2013 at 10:13 AM.
the LQ4 is 9.4:1, the LQ9 is 10.1:1. Both of those engines use the same VE table and MAF table from the factory. I dont have any pictures of the heads. They are just standard CNC'd heads. I will purchase the LC-1 now to monitor AFR and then if it knocks still with good AFR I will add race gas and see what happens. I did the calculation and with the stock cam's lift of .470" I am getting 30 cfm more flow with the ported than stock heads. I also added a catch can.
Referring to post # 16.. Did you check the FP @ WOT??
Chuck L.
CODY Motorsports
Fuel Injector Service
Madison, GA.
706-342-3152
770-265-5144 [C]
Posting Permissions
Reply With Quote