Phantom knock, Afratioest is off + Adjustable Cam Gear Tuning Question

[bigbird94]

I am new to tuning and just starting to street tune with ecmlink v3 Lite.
Since day one my car has been plagued by terrible phantom knock. For a while I couldnt even drive it without getting ridiculous counts of knock all the time (brand new KS)... The only way to help the problem for me was too pull a LOT of timing on my sliders and on my timing table. As you can see in the log it likes to knock, but if I remove my foot from the petal quick, it goes away.. I am not making a lot of power, I am sure it is due to all the timing pulled. If I put the sliders up any further Ill get high rpm knock... I am wondering if my cam adjustable cam gears are the problem. When I bought my car it was tuned on an AEM EMS and the exhaust cam was 3* advanced and the intake cam 2* retarded. My CAS is turned all the way counter clockwise. I am guessing that would be all the way advanced? I do not have a timing light so I did not set base timing, I was told it was set to 5* btdc before being tuned. If anyone can clarify please do.


Car:
93 GSX 5spd
Rebuilt 6 bolt

Important Mods
td05h 20g turbo
3"exhaust
link v3 lite w/ SD
Kelford 272 cams
Supertech valve springs
Fidanza cam gears


My AEM wideband is right around where I want it throughout the rpm range (11.5) but my afratioest is low, what can I do to make these line up? I know its related to the VE table but I have never played with that table and really do not understand how those changes affect the car.

 

[My1GLaser]

The CAS should be somewhere near the middle. You HAVE to time it with a timing light before doing any tuning. If its 10* off and you set your fuel & timing sliders then change the base timing you can pretty much throw everything you did out the window. Yes you need to set it to 5* BTDC with a timing light!!!

Did you know that you have a knock sensor circuit malfunction trouble code in the ECU?

IMO it looks so far out of whack that I would just start over.

Zero out the adj cam gears.
Verify valve timing is correct.
Set base timing with a timing light. (Note what the timing is before you change it for an idea of how far off it was.)
Take it for a spin and see if you can pull the timing sliders back to zero.

Are you running 950 inj? Did you do idle and cruise tuning? Your LTFTs aren't way out of line.

Your AFRatioEst looks close enough to me.

 

[turboglenn]

All the way counterclockwise would be fully retarded... that's rotating it the same direction that cam would be turning, turning it against the rotation of the camshaft would advance it.. I'm dealing with something similar but mine's in a software setup on my haltech ECU , but i have mine all the way advanced to get timing zero'sd, but i came to the decision tonight that my timing light is junk and needs replaced

Anyway, cam timing can have an efffect on an engines desire to knock, but actually advancing the exhaust cam and retarding the intake cam is the best addition of power i've found for my car, and in some reading i've heard both ways that this can increase tendency to knock and that it's the opposite that increases knock tendancy.

NOw , what i have to say here may not hold true to your case, and it might worry you, but i'm just tossing it out there.. When i went through a deep puddle and sucked up water in my old stock 6 bolt, i bent a rod from hydrolocking the engine and although it didn't effecthow the engine ran, ANYTIME i was over about 4200 RPM it would drive my aftermarket knocksensing system crazy, the noise it was making from the bent rod couldn't be heard, nor could the effects be felt in the driving of the car but it was making a ton of noise that even the best aftermarket knock system couldn't distinguish from real ignition knock/detonation.. SO as horrible as it might be, you shyould check for mechanical damage to the engine if after sorting out the rest of the electrical you are still unable to resolvethe knock issue

Another few things to check are physical noises from things around the engine. I JUST fixed my A/C today (replaced condensor and charged the system) and the sounds of the AC pump kicking in and out will register on my knock system, which is designed and specially reprogrammed to deal with high perfpormance 4g63 engine noises, uses a saturn knock sensor and is about the only KS i trust to tell me anything about tuning.. I guess what i'm trying to say is it doesn't have to be knock to set off that sensor and in fact a lot of times when it's constantly going crazy i've found that it isn't real knock but something noisy in the transmission, engine accessories or suspension that'sn setting it off.. check and eliminate possibilities one by one and eventually you'll get on the right track, sorry i can't be more definitive with what ot look at but almost any metal on metal noise is enough to drive the KS crazy

 

[bigbird94]

Thank you for the responses.


My1GLaser, I was aware of the DTC, after clearing it, it has not returned.

I am going to do as you said and zero everything out, and re-time the car. I am not wild about spending $100 on a timing light though.... Oh well.

I am running 950cc injectors.


turboglenn, I really do hope that there is no mechanical damage done to my engine but if this phantom knock doesnt go away the possibility will be investigated. I have searched all over for other noises that may be being picked up as PK but with no success. The only thing I can think of is a noisy lifter.