super88mr2

I did a couple pulls tonight with a base pfc map. At around 4600-5400 I got the exhaust overheat light to blink a few times and then it went out. Pull started at around 3k in 2nd and ended right after hitting 3rd. My knock count was 66 (peak) and my injector duty was (83.3% peak) I know the light blinks for knock and injector duty warnings but neither of those seems very high. I decided to see what my peak timing was and it said 51 degrees (Leading)! Is that reading accurate even though I wasn't monitoring timing during the pull? I sure hope it wasn't trying to advance timing by 51 degrees during acceleration.

Also, I did a ghost trace prior to this pull and that was in 2nd gear from 3,000 to about 5,500 because I saw the light blinking and could feel timing being pulled. When I looked at the trace it was strange. It increased as normal dropping cells as load increased and going towards the right as rpm increased BUT it also kept going straight across as if it was sitting at idle.

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That's roughly what it looked like. It increased all the way to cell 20 but I never even got close to that in revs. The load looks normal, stopping at cell 17. Id like to know if any of this sounds normal. My guess, before you guys school me is -- that it's seeing those cells and that amount of timing when I let off the throttle...at least that's what I hope...Mods on the car are: downpipe, catback, cone filter....boost avg's around .67-.72 peak.

thewird

iTrader: (8)

The thing with peak reading for timing is its always going to read the highest point on your map that you achieved. Which means its going to take the highest value from your regular driving in vacuum or when you let off at high RPM which is probably where your 51 came from. If your knock and injector duty cycles aren't triggering the engine light, then possibly a sensor is going out of spec like the TPS. See if the voltage goes out of spec when you full throttle.

thewird

arghx

iTrader: (3)

The default threshold is 60 knock counts to illuminate the warning. It really depends when the 66 occurred. Datalogit logs will help you figure out whether it is something to be concerned about. Some engines are noisier than others. One thing to try is to retard the trailing a little bit (increase split) to see if that affects the knock numbers. The default leading map is plenty safe for stock turbos.

At high rpm and high vacuum (decelerating) that is right. Look at the IGL map and it will make sense.

The PFC is not capable of pulling timing in response to the knock sensor signal. This is explained in the PFC Commander manual. You may have ignition breakup though.





Hard to say what that is, but I wouldn't be concerned about it.

Yeah that's normal.

super88mr2

I figured the 51 degrees was when I shifted (I had looked at the leading table and saw 51 only at no load conditions so that's what I had initially hoped it was) As for me feeling the timing being pulled, I may have been incorrect because when the light did flash it was right around the transition so that may have been what I was feeling I just saw the light go off and jumped to conclusions I think. If it WAS ignition breakup, what components usually cause this? The car has brand new plugs and wires...

You mentioned split, that's the one thing I've been wondering about. As you stated arghx, retarding my trailing plugs will increase "split". I have been reading on here about people tuning actual "split tables" so I was under the impression that there were actually 3 ignition tables.

Correct me if I'm wrong. Hypothetically if my leading is at say...15 degrees for cells 5 and 5 and my trailing is at 10 degrees for cells 5 and 5 then I'm sitting at a 5 degree "split" for that cell..and if I were to retard that trailing to 7 degrees timing then I would be at an 8 degree "split" and if at any time my trailing is higher than my leading then I am at a "negative split" which is something I wouldn't try to mess with until I get a wideband/datalogit (which btw are on their way).


Thanks for the responses guys.

thewird

iTrader: (8)

The split table is something you can only see with the datalogit and doesn't actually exist. The FC-edit software calculates the trailing map based on your desired split map. I'd wait until you get your datalogit before you start messing with it. But yes your assumption on how the split works is correct.

As for possible ignition breakup. If you already changed your plugs and wires, then it can only be the coils. However, usually people just get the twin power and coils are rarely replaced unless they are actually bad and/or twin power doesn't fix the misfire.

thewird