Am I experiencing detonation?

[oplix]

I've started having a problem recently. It might be due to installing a turbo back exhaust because for some reason my boost seems to spike higher than on the stock exhaust.

Anyways, Whenever I WOT my car, I will experience a stutter or hiccup if you will. Now if i keep it at WOT through the stutter, it will stutter again a few seconds later. The stutter doesn't last more than a second but it's really annoying.

I'm running a Evo 3 16g @15psi, new NGK BPR7ES spark plugs, new ACCEL 300+ Thundersport plug wires, 3" Turbo back exhaust, intake, Turbo XS Bov, Joe P MBC, and a boost gauge.

Does this sound like detonation? When the stutter occurs i can hear a sort of "pop" noise almost sounds like backfire.

 

[r1991_4g63t]

sounds like fuel cut to me

 

[r1991_4g63t]

i bet if you had a logger you would see that your fuel system is getting maxed out. mine will do it everyonce in a while and my car is 99% stock

 

[oplix]

I thought fuel cut felt more like a "brick wall" than a quick stutter.

 

[r1991_4g63t]

call it what you will but whenever mine did that i could look at the logs and see either the MAS or inj DC maxed out

 

[oplix]

I think you are right. Maybe my boost is a bit too high since I do have a stock fuel system right now.

 

[Zenja]

call it what you will but whenever mine did that i could look at the logs and see either the MAS or inj DC maxed out

That's not fuel cut, and neither is what the OP is having.

Knock on DSMs shouldn't really cause a stutter. Once it detects knock, it'll pull timing and it'll instantly pull slower, so you can feel something when that happens. But stuttering implies it's quickly changing between less and more acceleration, and it wouldn't do that because it takes a while for the ECU to slowly increase timing again.

I guess you could check for boost leaks. My car had a high RPM stutter when it was running too rich.

 

[r1991_4g63t]

That's not fuel cut, and neither is what the OP is having.

Knock on DSMs shouldn't really cause a stutter. Once it detects knock, it'll pull timing and it'll instantly pull slower, so you can feel something when that happens. But stuttering implies it's quickly changing between less and more acceleration, and it wouldn't do that because it takes a while for the ECU to slowly increase timing again.

I guess you could check for boost leaks. My car had a high RPM stutter when it was running too rich.

he didnt say it was, he was asking if it was. he experiencing the same thing i am, and it doesnt "knock" at all when it does it so it has nothing to do with timing. whats happening are the stock fuel system is getting over run by his mods.

 

[Mr Peepers]

Fuel cut is the ECU seeing a predetermined amount of airflow and shutting down the fuel supply in an attempt to save the engine(the fuel system may or may not be actually overrun). Boost leaks will cause it to cut out sooner. What you've described does and doesn't sound like fuel cut but try doing a boost leak test anyway.

Make sure your plugs are gapped at .028"

Some other things I've noticed to cause hesistations/sputtering/bucking are a bad fuel filter pick-up sock, fuel filter, or having the TPS unplugged.

If nothing else, turn the boost down since you have no way of monitering what's going on.

 

[viprez586]

Pull the plugs, you'll see small aluminum flakes or damage if you have detonation.
What is the small flakes from? Your piston.

 

[schroder]

Definitely not fuel cut...I had a stock 1g maf while running my b16g for about a week or 2 (Evo MAF now!) and when it started getting colder I still get to experience fuel cut around 17psi...You'll drive at WOT and around a certain RPM the car would, as everyone else has said, feel like you ran into a brick wall or rear ended someone. The nose dips a little and you def. feel the car cut fuel/spark. I had a studder uptop...If its audible, you could overrun be overrunning your maf and if you knock sensor is bad (as mine was and I had this happen sometimes too when I got it tuned with a higher fuel cut) its not detecting the knock from your motor as fast or as much so it doesn't pull the timing it needs to and you feel and hear the studder. Generally, if you can only feel it, and the studder feels like it wants to pull but it doesn't have enough spark, your too rich. THere is a difference in the feel, but its hard to explain until you've hit both. Hope my post helps and doens't confuse!