Timing Getting Retarted Into Negative

[nighthawklude99]

Ok so I have been trying to figuere out why my car runs like crap sometimes, but for the most part it runs great. The problem is that sometimes, and its never predictable always just at random times it will bogg and cause a huge loos in power. I alwayse thought it was because it was retarding the timing and finaly tonight I had my data logging laptop hooked up and was logging when the problem occured. When i get into any kind of boost, decel, and sometimes right when i got on it (then it would quit and run really strong, others it would continue to bog) it would pull timing all the way down to -14 at times but usualy -5 to -10. The tricky thing is that it only happens sometimes, not all the time and its never predictable. It also seems like it does it when its extreme hot (hotest days of the summer) or extreme cold (night like tonight mid to high 20's) this has been the first time it has done it since the hot summer days. What do you think could be causing this, my thoughts are knock sensor or mass. Does anyone know how I can logg knock to see if this is it? Timing is dead on 15 btc. Its really annoying, it makes my car non consistant and i cant stand that.

Thanks Jason





Car is a 1989 240sx hach w/ red top sr20det, front mount, 2.5 cold pipes, 3 hot pipes, apexi avc-r, tomei ecu(had stock sr ecu and did the same problem) 3 down pipe, 3 exhaust cutout.

[nighthawklude99]

Anyone have any input?

[LigouriRd]

Does your logger show anything in regards to knock? I could be that the ecu is sensing knock and reverting to a secondary map which has a timing retarded. How much boost are you running? If possible can you run less boost see how that effects the problem?

[nighthawklude99]

Im only running 10-12 psi (havent gotten apexi ebc dialed in yet) but when i was running stock boost. It also did the same thing with the stock computer. Im thinking its one of the sensors malfunctioning, but really not sure which one. I wish it showed me knock, might be a little easier to dial in on the problem. If anyone knows of a device or program that would show that (thats not $200+) i would be all over it.

Thanks Jason

[SoguRacing]

mine does this too. not sure what the problem is, i dont have any kind of data logger but every now and then the knock level on my SAFC goes up start at 0 then as i drive is slowly climbs, recently has reached as high as 30. dont know how to fix this either.. just thought i'd add that