AlwaysinBoost

iTrader: (17)

Just like the title says, I'm getting some funky knock counts when I transition between closed and open loop. It happens more so when I build a small amount of boost (less than 1psi) and lift off the throttle. According to the logs, right when the manifold goes from positive pressure to vacuum, it knocks anywhere from 2-10 counts.

I've tried adding fuel, removing timing, I checked and rechecked that nothing is hitting anything cause false knock. anyone have any ideas?

And

have you tried det cans to check?
you could adjust the knock load at the rpm to a little higher so that it doesn't register, if you know its false

Boosted Tuning

iTrader: (12)

What load is this happening at?

AlwaysinBoost

iTrader: (17)

And, I don't have Det cans.

Jay, this is happening right around 100 according to 1byte load

Boosted Tuning

iTrader: (12)

You may wanna try raising the knock load, like And said.

AlwaysinBoost

iTrader: (17)

I wanted to use that as a last resort of there were no other options. I don't like messing with knock thresholds.

JordanS4

iTrader: (11)

I was having the same problem as well on my 2.3 with headwork/cams, try lowering the threshold where it crosses over (85 load, ex.) and make sure your open loop fueling is good. That seemed to work out some of the knock for me but I'm sure some of it is phantom as well.

AlwaysinBoost

iTrader: (17)

my open loop fueling is suspect... maybe I'll try to nail that down a little better. I keep on chasing my trims and everytime I touch my inj scaling I have to redo the whole fuel map, lol.

Boosted Tuning

iTrader: (12)

Yes, messing with the knock thresholds should always be a last resort.

But, if you looked at the knock thresholds, the stock ones are low and can be raised a lil IMO.

fryedchikin

How do your AFR's look just before and after the transition ?. I spent hours tweaking the fueling to end up with a smooth transition but eventually eliminated all but the occasional 1 count of knock when going from closed to open loop.

stunt2

iTrader: (8)

what about disabling closed loop, put the ecu in constant open loop and map the car that way ?

AlwaysinBoost

iTrader: (17)

I think first I'm going to throw some race gas in the tank to see if this low load knock is real or not. If I'm still getting it after running high octane then I'll probably increase the knock load threshold.

EVO8LTW

iTrader: (41)

I used to fight that all the time. I also used to think it was false knock, but it wasn't. The solution was partially lowering the open loop load threshold to keep the AFRs in check, but mostly eliminating large timing jumps. Look at your timing when it knocks. If it comes down from too high too quickly, it will knock.

AlwaysinBoost

iTrader: (17)

How do you go about changing the open loop threshold and how would that effect the knock I'm getting?

I think my timing map is good with jumps. The most I have after 100 load is 3*, but mostly its around a 2* increase. Here is a log from the ride into work this morning to show what I'm talking about.



I know the fueling still needs work, as I said before I've been chasing my trims but I think I finally have them nailed down so no more rescaling injectors. As you can see the timing doesn't move around much at all.

EVO8LTW

iTrader: (41)

You are really rich in the 90-something load range. At 1 psi you definitely don't need to be any richer than 12.5 AFR. Being too rich can trigger knock. As far as changing open/closed loop crossover points -- that may not be your issue here, but there are two "open loop load" tables that have the values for various RPM ranges when the ECU will go from closed to open loop.