I read a lot of archives last night on the topic of detonation.

I see a lot of issues that people have with high compression and too much timing, and one of the common suggestions is to retard the dizzy.

However the symptoms I read about seem to mention the rattling/rocks/bbs noise while the motor is under load, especially around 4000rpm.

My motor works great when I hit the gas so that's why I'm confused.

However, I have noticed at lot lately, that when I decelarate, foot off the gas, wideband reading 19.9, I hear and feel a strange rumble/popping from the engine bay.

Could that be detonation, and if so, how, because I thought fuel stops spraying upon decelaration? or is it ignition that is cut when you decelarate? or both?

I have a b16a2 with CTR cams and pistons and and ITR lsd tranny. I was wondering if perhaps it could be a diff/drivetrain issue.

Any thoughts? I'm not sure what I'm hearing.

Maybe I'll burn another CROME chip with the knock sensor enabled.....

 

It ain't knock. You may be getting some backfire. Unburned fuel igniting in the exhaust system.

 

You need to datalog to know at what manifold pressure and rpm the event is occuring.

But I would recommend turning fuel duration and timing down using crome.

 

If you'r running a Honda ECU then when you chop the throttle then the injector duration goes to zero. There should not be any knock at all. There's nothing to burn.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">If you'r running a Honda ECU then when you chop the throttle then the injector duration goes to zero. There should not be any knock at all. There's nothing to burn.</TD></TR></TABLE>

That's what I was wondering. This is a 2000 Si with a conversion harness to a p28 socketed with moates.net equipment.

Perhaps its time to invest in datalogging equipment.

Is injector duty cycle and fuel duration the same or two different things? If different, where is that set in CROME?

 

Check you decel fuel with a wide band O2, if its to rich you may be experiencing mild back fire. I just corrected this problem on my car, decel was ~11 AFR way to rich.

 

"Dee Dee Dee!" - Carlos Mencia

It was just a loose tie-rod.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ( o )( o) &raquo;</TD></TR><TR><TD CLASS="quote"> It was just a loose tie-rod.
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It happens to the best of us