Detonation problem with 14* timing!!

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blackLX91

Member

May 1, 2002

31

0

6

Wisconsin

Sep 12, 2006

#1

• Sep 12, 2006

• #1

I've set my timing at 14* and run 92-93 octane pump gas. I noticed that when i run it hard it kinda seems to breakup at around 4500 rpm and higher. I'm trying to figure out the best way to solve the problem. I am also wondering if the gas here is affecting it, because we have the reformulated crap maybe the octane isn't quite what it is advertised at. I am gonna try backing it down to 13 and see what happens but is it possible the damper spun? My car is basically stock and just turned 27000 origonal miles the other day. I wouldn't think it spun so soon but who knows for sure. Anyone have a similar problem?? Any help is appreciated, THANKS!!!

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

Sep 12, 2006

#2

• Sep 12, 2006

• #2

All things mentioned sound plausable.

If you back down timing and the issue continues, I'd check the ignition and fuel side of things. On the ignition, a large plug gap can cause a high RPM misfire. A failing ignition coil or TFI (in the very early stages of failure) can act like this.

Or simply outrunning the fuel pump and losing pressure/volume at those high RPM's is possible.

Yanking codes is always a good idea. Things like lean/O2 codes, or IDM codes can be helpful clues.

Good luck.

 

P

postalbunny

Member

Oct 26, 2005

118

0

17

Sep 12, 2006

#3

• Sep 12, 2006

• #3

Had the same issue as you after I spun the balancer... replaced balancer and it fixed the vibration issues but had a breakup after 3k rpm.

Turned out to be the TFI module... problem only occured after motor had warmed up too.

 

Flavadave4

Active Member

Nov 28, 2003

1,044

21

49

Utica, NY

Sep 12, 2006

#4

• Sep 12, 2006

• #4

yeah if you dont know what the true octane is it could really cause problems at 14*.......back it down a little and see if it corrects itself.

IMO its better to start with the easy obvious things before you start ripping and tearing.
GOOD LUCK

 

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BadAndy

Founding Member

Feb 21, 2001

766

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0

Ohio

Sep 12, 2006

#5

• Sep 12, 2006

• #5

might try some lucas fuel injection cleaner

 

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blackLX91

Member

May 1, 2002

31

0

6

Wisconsin

Sep 13, 2006

#6

• Sep 13, 2006

• #6

Everything u guys mentioned is on my list of near future mods! Crazy huh!!! Yea i'm gonna back it down to 12or 13 again and see what happens but everything you guys said makes sense. Thanks, if it ever stops raining here i'll try and figure it out! Hopefully its not the coil it is a pretty new msd along with the ignition box. We'll see.

 

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GREYFOX4INCH

Member

May 8, 2005

190

0

16

western MA

Sep 13, 2006

#7

• Sep 13, 2006

• #7

when you say that its "breaking up" that makes me think missfire, not detonation.
my car is around 12-14* and pings on warm days (i have to back it off) some cars dont like alot of timing, there all a little different.

 

FORCED2DV8

New Member

Jun 6, 2005

458

0

0

Grand Rapids MI

Sep 13, 2006

#8

• Sep 13, 2006

• #8

Like HISSIN said, check the coil and tfi module, and the rest of your ignition system, wires rotor cap, You might have to back the timing down a little.

 

Black1987Stang

Active Member

Aug 22, 2004

1,422

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37

Jersey Shore

Jun 13, 2007

#9

• Jun 13, 2007

• #9

See if your balancer spun....Just put it to TDC on compression stroke and pointer should be at 0 on balancer, if not it's spun. I hear platinum plugs will do that too sometimes, esp with too big of a gap or weak ignition. Also if you have a MSD box with the rev limiter in it, take the chip out and see if that's it, a chip caused my friend's to break up earlier than what it should have. I would put it to stock timing (10degrees) once you find out if the balancer is spun or whatnot.

 

Darkwriter77

Resident Ranting Negative Nancy

5 Year Member

Jul 1, 2005

314

281

134

Apache Junction, AZ

Jun 13, 2007

#10

• Jun 13, 2007

• #10

Same here. Hot days (95*+) = pinging @ 3/4 throttle and above, usually above 3k RPM. I'm suspecting that having the EGR spacer coolant lines deleted might influence the matter a little, but it only happens on the hotter days above 95* for me, or if I've been sitting in traffic a lot and my temp gets above 205* or so. Backing the timing back down as far as 12* didn't do diddly, and even going all the way back to stock 10* didn't cure it entirely - still get light pinging above 3,500 RPM when I'm up to full operating temp, when ambient temps are hot.

Maybe it's largely a MAF and/or IAT sensor design issue...?