need scan tool help.

[CSXT802]

I just got a used OTC 4000E scanner. It works great, but now that I see what the car is doing I'm worried about driving it.I started a post last month after my dyno numbers fell short of what I expected. http://www.turbo-mopar.com/forums/showthread.php?t=4328

well today I got to use the OTC to figure out why my car feels flat up top.
according to the scanner I'm getting knock retard starting at 9-10 psi of boost. This seems way to low to be picking up knock retard.
I'll list some basic stats and let me know what you think.
Car set up:
FWD stage 5 3 bar cal.
12 deg. base timing
BR9ES spark plugs .035 gap
1080 cfm spearco FMIC
46 trim T/3 T/4 turbo
+ 40% injectors
93 octain pump gas with a bottle of lucas octain boost added
now here are some of # off the OTC when the knock retard happened
air charge temp 75-90 deg.
coolant temp 185-200 deg.
elec advance at idle showed 16 deg. cruse no load no boost 24-31 deg advance
now once the car hits the 9-10 psi mark I show knock retard on all 4 cylinders. #4 and #1 show knock first.
I backed off my base timing to 8 deg advance but it made no differance.

[inmyshadow]

I would tighten up the gap on the plugs. I keep the gap under .030 on the Champion plugs. I'm assuming the BR9ES is at least one heat range lower then stock.

You could also try moving the injectors on the cylinder that are knocking. See if the knock follows the injectors.

[CSXT802]

On the OTC 4000E when it shows electronic advance is that total advance.? Or is it advance on top of the base timeing.?

[inmyshadow]

I think its on top of base timing.

[ShelGame]

Are you reading that boost from the OTC or your boost guage? If it's from the OTC, you need to multiply the boost by 3/2. Scantools don't know you have a 3-bar MAP and scale the values coming from the SMEC as if it was a 2-bar.

So, your 9-10 psi boost may actually be 14-15psi...

[CSXT802]

Are you reading that boost from the OTC or your boost guage? If it's from the OTC, you need to multiply the boost by 3/2. Scantools don't know you have a 3-bar MAP and scale the values coming from the SMEC as if it was a 2-bar.

So, your 9-10 psi boost may actually be 14-15psi...

I was reading the boost guage. the knock act goes from no to yes at 9-10 psi on guage.

[MiniMopar]

What is the O2 voltage while the knock is happening? Is this a 2.2 or a 2.5? What cam are you running?

[CSXT802]

What is the O2 voltage while the knock is happening? Is this a 2.2 or a 2.5? What cam are you running?

It's a 2.2, I don't know what the O2 voltage was but my A/F gauge showed rich. the cam is a 88 T1 roller.

[ssheen]

What is the TPS voltage?

[iTurbo]

How much advance does the 4000E show when at WOT? FWIW, my stock TII logic module says '9' in the ADV parameter. My base ignition timing is 12' BTDC so total timing in my case is 21 degrees at WOT. I'm pushing 18 psi and only get a hint of KR on #4 just when full boost (18 psi) hits. This is on a pretty much stock TII w/3" exhaust setup though.

[MiniMopar]

Hmm...something is afoot. Has the head ever been milled? It doesn't sound like anything is wrong with a particular cylinder. Seeing #4 first is pretty normal.

[CSXT802]

Hmm...something is afoot. Has the head ever been milled? It doesn't sound like anything is wrong with a particular cylinder. Seeing #4 first is pretty normal.

The head and block were decked when I built the motor. Nothing drastic just enough to make sure they were flat.

[Akromix]

I had this same problem...turned out carbon buildup was at fault. Once I cleaned all the flaking carbon from the head and pistons the knock disappeared.