Notices
SC - 1st Gen (1992-2000)

ignition breakup or spark blowout ????????

Thread Tools
 
Search this Thread
 
Old Aug 16, 2008 | 09:32 AM
  #1  
lexforlife's Avatar
lexforlife
Thread Starter
Lexus Fanatic
iTrader: (7)
 
Joined: Dec 2002
Posts: 6,864
Likes: 18
From: So Florida baby
Default ignition breakup or spark blowout ????????

guys i need some good insight here

i need to know opinions with reasons behind them for this

when on the highway crusing in 5th and i down shift to 4th around high 3k rpm range and car builds boost fast (t67dbb) i hit about 19ish 20psi and car bucks a few times then shuts off . i would pull over turn key off and restart no problem

could this be spark completely blown out and cyl being flooded with fuel . i do notice egt temp climbs fast while in this 4th gear while boost builds but funny thing it doesnt happen too much if i am in higher rpm band while doing 4th gear pull doesnt happen at all with 2gear pull or 3rd gear pull


could this be too much timing advance in that rpm range and makes car shut off because reg knock from knoeck sensor and pulls timing to the point of shut off

car is a 97 sc300 na-t so its obdII

550 inj
t67dbb 68back
boostlogic manny and piping
map ecu
2.5headgasket
ngk plugs 6097 gapped at .024-.025

running around 19 to 20psi is this too much boost for stock ign with no hks twin power


i am thinking spark blow out completely and with fuel dumping no chance of reigniting while under boost
Reply
Old Aug 16, 2008 | 12:00 PM
  #2  
SCoupe's Avatar
SCoupe
Lexus Test Driver
CL Folding 25,000
 
Joined: Aug 2003
Posts: 887
Likes: 0
From: California
Default

fwiw: My plug blow out / mis-fire issue was solved when I re-gapped the 6097 from about .28 to about .26 with ~18psi on CA 91 oct pump gas.

You're already at .24 gap

The three suggestions for me were re-gap plugs, coil packs and ignition wires in that order, the plug regapped solve my issue and I went no further.

T61 single, 2jzgte, 700cc top feed, Apexi NEO, Blitz EBC making 440 whp. I'd offer suggestions but your situation is past my meager abilities.
Reply
Old Aug 16, 2008 | 06:36 PM
  #3  
thaimonkee's Avatar
thaimonkee
Lead Lap
iTrader: (2)
 
Joined: Nov 2003
Posts: 795
Likes: 0
From: Maryland
Default

i had a spark breakup problem too. Im running a pt67 also. i was gapped at
.26 and started getting breakup around 18 psi. we couldnt get past 369 hp. then we regapped it to .19 and got 509 hp at 23 psi but that was maxing out the stock ignition.
I wanted more so i installed the hks DLI and made 543 with same boost.

my opinion is either gap it lower or install a DLI.
Reply
Old Aug 17, 2008 | 05:29 AM
  #4  
lexforlife's Avatar
lexforlife
Thread Starter
Lexus Fanatic
iTrader: (7)
 
Joined: Dec 2002
Posts: 6,864
Likes: 18
From: So Florida baby
Default

Originally Posted by thaimonkee
i had a spark breakup problem too. Im running a pt67 also. i was gapped at
.26 and started getting breakup around 18 psi. we couldnt get past 369 hp. then we regapped it to .19 and got 509 hp at 23 psi but that was maxing out the stock ignition.
I wanted more so i installed the hks DLI and made 543 with same boost.

my opinion is either gap it lower or install a DLI.
when you had your worst breakup did the car ever just shut off while in boost
Reply
Old Aug 17, 2008 | 01:44 PM
  #5  
thaimonkee's Avatar
thaimonkee
Lead Lap
iTrader: (2)
 
Joined: Nov 2003
Posts: 795
Likes: 0
From: Maryland
Default

it never shut off. it just started missing like crazy. I have no idea why yours would cut off while driving...sorry
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Superjatt
SC - 1st Gen (1992-2000)
28
Sep 26, 2015 03:55 PM
Bigzavs
SC - 1st Gen (1992-2000)
14
Aug 10, 2012 09:59 PM
SC300_704
SC - 1st Gen (1992-2000)
2
Dec 4, 2010 11:07 PM
reddot
RX - 1st Gen (1999-2003)
10
Aug 29, 2009 05:52 PM
builtsohc
SC - 1st Gen (1992-2000)
5
Jun 3, 2006 04:15 PM




All times are GMT -7. The time now is 08:38 AM.