Need advice: Knock @2500-3000 rpm

[Abdulla]

Hi All,

1. Getting KR (knock) in 2500-3000 rpm range (Noticed it on the dashboard while logging for AUTOVE) however, I couldn't hear any audiable knock (or maybe I got used to it reason of a broken tooth on the diff.ring!)

2. Commanded stoich A/F is (14.68), but it is enriching ~10% upto 13ish sometimes with no apparent reason in reference to tune setup
My brain has stopped working .. need yours for a while

My setup:
-OLSD
-MAF disabled & force failed (unwired)
-Disabled CAT protection
-Hiked main VE by 10% more across the board
-NB-o2 feedback disabled
-WB-o2 A/F is in sync all over (LC-1, gauge, V2, Logwork, GM.AFR)

Engine Mods: Bank's Ram CAI "this huge CAI sent my MAF (out of range) on day 1 - no over oiling/clean MAF-, yet couldn't figure out the reason!"


Thanks

[WeathermanShawn]

Really does not look like that much KR. If real, it probably is just having trouble with those high IATS.

I see your Spark IAT Table is 'enabled'. You can always take out 50% more Spark per that Table, or just lower your High-Octane Spark in those areas.

As far as your fueling, if your AFR/EQ is bouncing around that much, why not go back to closed-loop for a while..or you are just going to have to dial in your VE Table even better.

Thats all I have..

[Abdulla]

Thanks Shawn, appreciated

Really does not look like that much KR. If real, it probably is just having trouble with those high IATS.

Well, taking all the precautions in advance I drove it around 3:30-4:00 am early morning..the coldest IAT I can get here

I'm leaning toward the burst knock, however, I thought to do the same as you suggested and I will as an additional precaution, any other suggestion is welcome

Commanded A/F:
I found that A/F is in negative correlating to MAP @MAP =>60 kPa (pic attached) despite my setting to enrich the commanded A/F beyond 65 kpa, while below 60 commanded A/F stays at 14.68 regardless of any other parameter (Ok, 5 kPa error.. maybe not a big deal)

Sofware Question:
for example, when I highlight (70 kPa-MAP) in the scan tool chart, the corrosponding value which is highlited in tune tool (main VE) is showing 15 kPa in the column..! am I missing something here?

[joecar]

In scantool, on PIDs tab, on the MAP pid do rightclick->Metric, this will hightlight the correct column in the tunetool.

[joecar]

For the commanded A/F, use the scantool->tunetool cursor linking to see which cell in B3605 it is commanding from.

What are you using for fuel (alcohol content)...? Are you sure it is using only B3605...?

[WeathermanShawn]

Abdulla:

If you find OLSD a little challenging, I have found that just by going to CLSD for a week or two may help you to 'clean-up' your VE Table. Trims computes many times per second..in reality they are a good way to integrate fuel differences over time. Some may find that easier than trying to do it all by WO2BENS. Obviously, you would just apply the LTFTBEN percentages against your existing VE Table.

Just an idea if your fueling remains erratic...

[Abdulla]

on the MAP pid do rightclick->Metric

For the commanded A/F, use the scantool->tunetool cursor linking to see which cell in B3605 it is commanding from.

What are you using for fuel (alcohol content)...? Are you sure it is using only B3605...?

Thanks, Joe. I do apologize for the way I did put my previous question, B3605 is sat to 14.68 (equiv=1) upto 60 kPa, and to enrich at 65 kPa and beyond at my normal operating temps ranges (I overlooked that when I posted the question), however, I'm wondering why it is enriching earlier at 60 kPa.

I'm worried more about that KR, the engine is running at actual A/F of 13ish in that zone, I will pull some timing in that zone and give it a second try tonight and see how much big hole I can put through the piston

Fuel: 98 octane (RON)= (~93 R+M/2 in USA/Canada), no alcohol as far as I know

Thanks

[Abdulla]

Thanks for your follow up Shawn, In fact I'm doing all this just for sake of learning and helping others, so CLSD and LTFT is on the "to-do list" too. ^_*