Hrmm...Let's discuss Spark Plugs+Gaps+wires? - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 08-25-2008, 11:37 AM   #21
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,796
Total Cats: 247
Default

Gap new plugs to .020. Fixed. Then tell us how it didn't affect idle, cruise, mpg, or anything else.
patsmx5 is online now   Reply With Quote
Old 08-26-2008, 02:51 AM   #22
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Nov 2007
Location: orlando, FL
Posts: 558
Total Cats: 0
Default

lol... i guess i'll try the .020?...i hope you were joking about idle cruise mpg and everything else.... hahaha
XxGoKoUxX is offline   Reply With Quote
Old 09-07-2008, 11:46 PM   #23
Junior Member
 
Join Date: Sep 2008
Location: ATL GA
Posts: 290
Total Cats: -217
Default

i had the same problem after i moved from GA to CA every time i would pull hard to 7k i would start to lose power and sputter around 6k till 7k so i checked my #7ngk plug and the cap was at 35 i changed it to 29 and that fixed the problem car runs great all the time. i thought about the COP option but the most i ever boost now is 15psi i think ill get a oil cooler first.
locomonkeyboricua is offline   Reply With Quote
Old 09-08-2008, 01:01 AM   #24
Elite Member
iTrader: (17)
 
Join Date: May 2007
Location: NY
Posts: 1,614
Total Cats: 2
Default

I'm curious to hear back from the guy patsmx5 suggested to regap to .020..

I'm THINKING I;m experiencing blowout. Also no backfire, dont think I'm seeing misfire (at least cant notice) either.

What I AM experiencing is when I pull the car hard, I sometimes get a sudden loss of power/RPM. It doesn't happen everytime, and only when really getting on it.
Perfect example, get on the car up to 6k rpm, then all of a sudden RPM's drop to 5kRPM, and then car comes back to life.
Been wanting to check the gaps, just haven't gotten around to it...
TonyV is offline   Reply With Quote
Old 09-08-2008, 01:19 AM   #25
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Quote:
Originally Posted by tvalenziano View Post
get on the car up to 6k rpm, then all of a sudden RPM's drop to 5kRPM, and then car comes back to life.
So you're seeing the tach drop suddenly from 6k to 5k and then come back, yes? Do you believe this to be reflective of reality? Seems to me it'd be difficult for the engine to actually do that in the period of time that I envision you describing.

When I was having trigger problems with my MS, I observed this behavior frequently while under heavy load- the tach would drop down suddenly, accompanied by a momentary loss of power, and then come right back. In my case, this was a pickup problem however, which was causing the ECU to not generate spark signals in the first place- misfire due to spark blowout should not actually produce the sort of tach dropout that I think you are describing.
Joe Perez is online now   Reply With Quote
Old 09-08-2008, 10:49 AM   #26
Elite Member
iTrader: (17)
 
Join Date: May 2007
Location: NY
Posts: 1,614
Total Cats: 2
Default

Yes I believe it to be happening, as I dont know anything else that could show my tach drop 1k rpm, even if my foot stays on the throttle...

Another thing is I can't duplicate the condition on command. Sometimes it happens, sometimes it doesn't. It's not WOT, but def 3/4 throttle...usually in 2nd or 3rd gear...right around 6k rpm.

I dont think I'm hitting any kind of fuel cut, and as I said a fuel cut would be very easy to duplicate.

I have to try and catch one of these in a DL
TonyV is offline   Reply With Quote
Old 09-08-2008, 10:55 AM   #27
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

Tony try to log the event. It's most likely spark blowout- I used to see the same before i went to cops with a .035" gap. Its also possible it's acceleration enrichments, under accel wizard your setup for TPSdot right?
Braineack is offline   Reply With Quote
Old 09-08-2008, 11:07 AM   #28
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

I don't see how spark blowout could cause a tach drop. Assuming he's using the stock tach driver of an early '95, the tach output of the igniter is not a closed-loop thing- it gets pulsed whenever the primary operates, regardless of what's happening on the secondary. If he's driving the tach directly from MS, or by diode-OR'ing the SparkA and SparkB triggers, then it's doubly impossible for a secondary-side fault to cause this problem. He's talking about an observable drop of 1k RPM on the tach that happens almost instantaneously, and the engine simply can't change speed that fast.

This really sounds like a CAS trigger problem to me. If you can log an event, I've got $0.01 that says it'll show as a very massive and rapid spike in RPM.
Joe Perez is online now   Reply With Quote
Old 09-08-2008, 11:09 AM   #29
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,796
Total Cats: 247
Default

Quote:
Originally Posted by tvalenziano View Post
I'm curious to hear back from the guy patsmx5 suggested to regap to .020..

I'm THINKING I;m experiencing blowout. Also no backfire, dont think I'm seeing misfire (at least cant notice) either.

What I AM experiencing is when I pull the car hard, I sometimes get a sudden loss of power/RPM. It doesn't happen everytime, and only when really getting on it.
Perfect example, get on the car up to 6k rpm, then all of a sudden RPM's drop to 5kRPM, and then car comes back to life.
Been wanting to check the gaps, just haven't gotten around to it...
Try new plugs gapped to .020 and see if it fixes it.
patsmx5 is online now   Reply With Quote
Old 09-08-2008, 12:25 PM   #30
Elite Member
iTrader: (17)
 
Join Date: May 2007
Location: NY
Posts: 1,614
Total Cats: 2
Default

I'm gonna try logging it, just keep the laptop in the car till I finally catch it I guess. Also obviously it won't hurt to check the gaps on the plugs.

I haven't messed with any enrichment stuff, not that far along yet, lol.
Just getting the hang of tuning, DLing, etc.

AND I really need to get on my EzTherm...my CLT temp values (and prob Intake Temps) are way off... On a good run my CLT shows CS140's-HIGH170's...
TonyV is offline   Reply With Quote
Old 09-10-2008, 11:07 AM   #31
Elite Member
iTrader: (17)
 
Join Date: May 2007
Location: NY
Posts: 1,614
Total Cats: 2
Default

Regapped plugs, I guess I had them on NA gaps? (.035-.040)

Bought them down to .020-.025

Also gonna do some logging and see if I can repeat the event, though hopefully it was the gaps...I just dont know if they'd be blowing out at only 5-6lbs of boost, even with stock gapping
TonyV is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
FS/FT: 03.5 Mazdaspeed Protege leatherface24 Cars for sale/trade 15 10-16-2015 12:35 PM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
01-05 Fab9 PNP COPs (used) FrankB Miata parts for sale/trade 6 09-30-2015 12:48 PM
In need of AEM guidance W/pics E=MC^2 AEM 1 09-17-2015 01:34 PM
Obligatory "N00B" post! D_Breezy Meet and Greet 5 09-08-2015 06:37 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:03 PM.