Help with knock please

[400ss]

I have this 1989 chevy truck with 5.3L and magnacharger.. 4L60E and 3.73 gears, everything was fine with the stock pulley,
i upgraded the pulley from 3.5 to 2.9 inches..

problem im having is knock during part throtle mostly in 4rth gear, how can i remove this knock problem, looks like AFR is ok and i been removing spark advance on the areas it knocks and havent removed it..

or should i go COS speed density tune?

any help ill apreciate it

[joecar]

I see several problems:

MAP sensor pegs at 103 kPa (it seems to me that you would be in boost).

When MAP pegs at lower throttle (you're still in boost), wideband shows Lambda 0.86 (which is too lean for boost).

CALC.CYLAIR does not match GM.DYNCYLAIR_DMA, partly due to MAP pegging and partly due to air model being incorrect.

[joecar]

Your .ctz fails to open in the tunetool (nothing happens, tunetool is blank).

[400ss]

I open the file in Scan and Tune, then in the Edit tab and then in Edit with v7.5 and it will open in v7.5

when in part throtle in 4rth gear it will knock, i see it pegs at 103 but i think it only see low boost because the throttle is like in 40-50% and low RPM, and the wideband in those areas shows , 11.14-11.70
im runing in only MAF right now because i was tuning the MAF.. but i cant get remove that knock.. im using CYLAIR to track spark advance because when CYNCYLAIR_DMA will only track up to 0.68 grams/cyl, i dont know why

[joecar]

I open the file in Scan and Tune, then in the Edit tab and then in Edit with v7.5 and it will open in v7.5
...Nope, I can't even do that, it is greyed out...

I'm using V8 build 277.

[joecar]

...

when in part throtle in 4rth gear it will knock, i see it pegs at 103 but i think it only see low boost because the throttle is like in 40-50% and low RPM, and the wideband in those areas shows , 11.14-11.70
im runing in only MAF right now because i was tuning the MAF.. but i cant get remove that knock.. im using CYLAIR to track spark advance because when CYNCYLAIR_DMA will only track up to 0.68 grams/cyl, i dont know why

If you look in your log where TP goes to 99%, MAP is still 103 kPa (although it does not knock there, probably because PE fueling is sufficient).

[joecar]

Can you update your software, open and re-save your .ctz file and re-post it here.

[joecar]

Which V7 and V8 build versions are you using...?

[400ss]

If you look in your log where TP goes to 99%, MAP is still 103 kPa (although it does not knock there, probably because PE fueling is sufficient).


it pegs cause the truck has the stock MAP, right now is runing only with MAF, on WOT the truck will not knock, the AFR my wideband shows on WOT is 11.50-11.70

should i go COS 2 Bar?

[joecar]

My concern is that when TP is PT, MAP sensor is not reporting correctly, so fueling may be under... (I have to think about it).

Yes, you should take advantage of 2-bar MAP sensor with the COS.

[400ss]

Ill go cos2bar.. i used to think. That is the maf isnt pegging it can be tunes easily for boost. But the cars i tuned with cos 2 bar with forced induction where easier and simpler

[400ss]

Couldnt find a 2Bar map at the moment, here where iam..... im still working on this, but still having knock., did some changues on the tune, i will try it,, there is again the tune and a log

This tune file is the last one i modified but havent tried it,, the log is from the last tune used