tazza

I got a few screen shots. It doesn't seem to show the MAP settings. At idle i get: Throttle position: 9.4% Engine RPM: 662 load 1.6% Advance 10degrees, this does jump back to 7 every so often, not stable Inlet manifold pressure: 26KPA Air flow rate: 1.81 g/s Intake air temp 58c Coolant temp 93c In gear, with my foot on the brake i can get it to ping. Throttle 17.6% RPM 1725 Load 16.1% Timing advance: 23 degrees Intake manifold pressure 65kpa air flow 16.17 g/s The weird thing is, if i put my foot down harder to get higher revs, the ping stops and the timing advance drops to about 15 degrees. I thought with higher revs, the timing would also advance....

You are right, its a non turbo EJ20. Still waiting to go home and check the MAP settings, only a few more hours!

I don't believe it has a tumble generator valve, the plenum joins straight to the head. I will have to look tonight to see if it has an EGR valve or not, from memory i don't remember seeing one, but i will have to look to be sure. It has about 191,000k's on the clock. It is an auto, it is an ex rep car, so its done quite a few k's in a short time. I had never owned a subaru before this and had no idea that you were meant to use upper engine cleaner every service. I serviced it about 3 times and never knew to use it. I have since run quite a bit of engine cleaner through it as i wasn't sure if it was carbon build up or not. I have even taken it for a nice long drive up a mountain and highway to try and get it hot in an effort to burn any carbon it may have built up. I will have to look at the MAP value tonight. The advance when i tested it last night at idle was 7 degrees and jumped to 10, then 7 (it was a bit erratic) but at that time i don't know if it was at full operating temperature. When driving, not revving too high hit about 48. Any idea of what the advance should be at set RPM levels? I really appreciate the time you are taking to help me with this. I also know how hard it is to diagnose without having something in front of you.

I don't think it has an AVCS, not that i could find at least. Where should i look for a tumble valve?

Thanks for the idea. I have been using scantool, not sure it gives me any details on knock sensor inputs. It does show timing advance though. Its something for me to check out though. See if the advance changes when the knock occurs at a set throttle. I have run fuel system cleaner through it a few times, the fuel filter was changed not that long ago too.

Hi guys and gals. I have a 2005 Impreza GX with an EJ20. It has been pinging when the revs are in the 1,000 - 2,500 RPM range. Even on very light load, i have run multiple cans of upper engine cleaner through it. Tried different fuel. Its been doing it for quite a while now. Premium fuel does help with the noise, but its still there. I hooked up a timing light on number 1 and the timing is weird. The timing jumps back 15 odd degrees randomly, multiple times every second. It doesn't hold in the same point as you would expect it to do if it was firing at the right time. I suspect this is the cause of my engine ping. I have used two different types of light, both show the same thing. I 'tested' the knock sensor by using the timing light and watching where it was, then lightly tapping the knock sensor bolt, the timing rolls back then slowly returns back to normal. I figured this means the sensor is ok. The only other thing i can think of is the cam angle sensor or crank angle sensor. Is there a way to tell if they are ok? or would they cause this erratic timing retardation at random times?