Knock/lean condition

[BuickMike231]

Hey guys, I have been messing with this for a little while now and not sure what could be causing this. I have got all my Scanmaster numbers right where they should be and on a 3rd gear the other day I showed a little over 5 degrees of KR and the O2's were in the mid 400's...not good. The Casper's Knock gauge was pretty much maxed out too in the red. Would an RJC Power Plate help, could it be related to the front cylinders getting starved a bit? I'm running about 16 psi on 93 octane and the rest of my combo is in my sig. Any help or ideas would be appreciated!

Thanks

 

[turbocvc]

Are your MAF readings good at WOT? I was chasing a lean condition for a long time and decided to check my MAF readings on the sm one day and it would only show 140-150 at 16# of boost. The car ran fine just could not get into it in 3rd. The MAF seemed fine for everyday driving, I swapped it out with a good unit just to see and it gave me a better reading of 220-235 at WOT. I ended up getting an LT1 MAF and translator and it hasn't leaned out since with my same setup.

 

["Turbo-T"]

What's your fuel pressure look like?

 

[BuickMike231]

Fuel pressure is set at 43 psi line off, I honestly haven't confirmed that it raises one psi per pound of boost since I only have the direct tap fuel gage. I haven't watched the MAF numbers but I will have to check. I had to replace the MAF right when I got the car a few years back but I know the replacement ones are crap sometimes. I have been thinking about doing the LT1/Translator for a while just haven't had the cash to throw at it right now! Sounds like it worked out pretty well though. I'll try to check the MAF readings and post back! Thanks guys.

 

[BuickMike231]

I took the car out and couldn't really hammer on it, but MAF seems to be acting alright, I got into it a bit and got it to around 207 or so before I had to back off. What's strange though is I turned my TT chip's fuel back down ( I had it up to like 18% additional) to around +9% and it seems to have helped. Where the knock would slowly start to creep in and the two gauges would register something I didn't see anything at all on either gauge. I remember a while back reading something along the lines of too much fuel can create a fake lean condition or something like that, like the computer thinks it's running lean from having way too much fuel thrown in and it could show up as a knock reading. It seems to have helped though, I jumped on it what little I could and where I normally would have seen something on the KR in the Scanmaster and for sure would have had some lights on the Casper's gauge, I saw nothing on either. Maybe I was just choking it with gas...I have to play around with it a little more but it seems to have solved my mystery knock problem! I'll post if I find anything else, any body else see something like this before?

 

[bmackinnon]

Fuel pressure is set at 43 psi line off, I honestly haven't confirmed that it raises one psi per pound of boost since I only have the direct tap fuel gage.

That would absolutely be the 1st thing I checked.... do whatever have to do to verify fp is rising 1:1 with boost. Just get a hose to extend your gage and duct tape it to the windshield... that's what alot of people do.... cheap and easy...