Part Throttle Knock Is Killing Me!

[AWD_ENVY]

My fuel trims are now (as of lunch)
102,101,99.... still knockin like a hoe

Knock sensor was put in correctly... but I'm going to hit it with a sludge hammer if it dosent stop.

 

[EROK006]

Well I reset my ECU, it didn't make a bit of difference. What would cause my fuel trims to never change. No matter what I do with the VPC they stay the same. My O2 voltage changes it show rich just like the trims do. Hopefully this is what causing my knock. Because I sure as hell don't want to go through changing the amount of stuff AWD_ENVY has!

 

[AWD_ENVY]

Thanks


A local guy had the same problem as you, tuned out that his chip was a 660 chip when it was sappose to be for 550's..... you sure your chip is correct for your injectors ????

 

[EROK006]

The label on the chip is right it's for the big ol' 450's and that's what I have!! So I'm pretty sure it's the right one.

 

[AWD_ENVY]

Well... I took out the Knock Sensor and retourqed it to spec.

Didn't do squat


Anyone ?... please

 

[jdmawd]

Originally posted by jdmawd
hers is the setup base timing 9-11*'s base fuel pressure 38 psi (vac line off) 650 injectors 15 psi of boost. i get 40+ counts at part throttle from 3800-5K. the strange part is i have gone as low as -8 on the low table(3K-5K) and as high as +15(3k-5K) but the knock count is unchanged and o2 voltage does not move from .88v should i zero the s-afc turn boost down to like 13 and start over?

OK IM A DUMB A$$

im sure everyone but me knew this, but whatever. i took a minute and thought about how the ECU thinks the injectors are 450cc's and that the injectors are actually 650's.the chip in the vpc thinks the injectors are 660's that means i need to remove 20-25%. from the s-afc across the board, as a starting point. well sure enough, that did the trick. timing is up, knock is down. not gone, but down. *still need to tune it a bit more* timing never dipped below 17*'s. knock never went, above 15 counts. not good but a far cry from 43. i will tell you this, even at 15 psi and semi untuned. i have never driven a car this fast, in my life. this thing is SCARY fast. it always spooled quick, but fell flat because of knock. im sure lowering the base timing, and tuning 4K and 6K (that's where i still get knock at wot). this thing will really start to come around. thanks for everyone's help

 

[sunflashx]

Originally posted by EROK006
The label on the chip is right it's for the big ol' 450's and that's what I have!! So I'm pretty sure it's the right one.

It's the right one. I had no problems with that 450 chip. It ran almost stock for me. Then I switched to the 550 chip and hated the whole device.

Check your base timing, it will act like you are describing if it is too high. 3-5 works well where we are for pump gas.

Fuel trims won't move from like 80's with just the VPC. To tune rich enough for WOT with just the gain nob makes low throttle too rich. 80% fuel trims equal ECU thinking it's too rich and trying to pull fuel.

Have you replaced your ECU caps yet? Last I heard from you you hadn't.

I have a old knock sensor you can try that I know is good if you want. I replaced it because I thought it was bad. It had actually just backed out a half turn or sow and was wiggling around, but I replaced it anyway.

Response nob on the VPC is at maximum, right?

Base Fuel pressure at 38, correct?

 

[jdmawd]

Originally posted by jdmawd



OK IM A DUMB A$$

im sure everyone but me knew this, but whatever. i took a minute and thought about how the ECU thinks the injectors are 450cc's and that the injectors are actually 650's.the chip in the vpc thinks the injectors are 660's that means i need to remove 20-25%. from the s-afc across the board, as a starting point. well sure enough, that did the trick. timing is up, knock is down. not gone, but down. *still need to tune it a bit more* timing never dipped below 17*'s. knock never went, above 15 counts. not good but a far cry from 43. i will tell you this, even at 15 psi and semi untuned. i have never driven a car this fast, in my life. this thing is SCARY fast. it always spooled quick, but fell flat because of knock. im sure lowering the base timing, and tuning 4K and 6K (that's where i still get knock at wot). this thing will really start to come around. thanks for everyone's help

just a quick update, since knock seems to be the hot topic. i set base timing at 5*'s changed the plugs to ngk's number 7's. base fuel pressure is 43 psi. at 20 psi i get zero knock at 7200 and 18* of advance. tip in knock is gone,at every rpm point. 02 volage is .88 at wot.

vpc:
gain 12 0'clock
idle 6 0'clock
response 5 o'clock

SAFC:
for now LO 1k -30 -15 across the board

HI-10 across the board

 

[Turboniam]

Glad to hear you figured it out....

I have run into the same problem where it was just the "tuning" part and I was WAY too rich!

 

[jdmawd]

Originally posted by Turboniam
Glad to hear you figured it out....

I have run into the same problem where it was just the "tuning" part and I was WAY too rich!

so damn true, i think... i take that back, i know im super rich. but for now while tuning rich is better.