SaturnFans.com
what's new (beta) - classifieds - forums - photos


Go Back   SaturnFans.com Forums > Models > Saturn S-Series > S-Series General
Register FAQ Members List Groups Calendar Chat Room Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 10-19-2018, 10:14 AM   #1
HankHill
Junior Member
HankHill is on a distinguished road
 
HankHill's Avatar
 
Join Date: Jan 2013
Posts: 18

1997 SC1
Default Cyl 3 misfire at idle... couple dumb questions

So I've got a 97 SC1 with misfire at idle and corresponding P0303 code. I've replaced the spark plugs, which did seem to help a little, but so far that's all I've done. The misfire goes away as RPM increases, and the code will even clear on its own on a ~1 hr highway drive, but then returns after I've been stopped at a few lights. That leads me to suspect it's a vacuum leak (my logic being that if it was a spark or fuel issue would only get worse with RPM/load, and if it was a temp sensor issue it wouldn't affect only cyl 3).


But just to rule out ignition related issues, my noob questions:
- Are cylinders are numbered from pass side to driver's side, or vice versa? (Is cyl 1 or cyl 4 closest to the passenger tire)?
- Both plugs connected to a given coil fire simultaneously (one of the 2 being waste spark), correct? In other words, I should be able to swap wires between terminals on the same coil in order to rule out an issue with a coil itself? I suspect one or both of my coils have been changed, so the labeling on them may be what's confusing me here.

I think if I can rule out ignition, my next steps will be to:
- Verify the engine temp that the ecu is seeing to make sure it's not a t-stat or temp sensor issue
- Spray starting fluid around the intake manifold/cyl head to try and find a vacuum leak
- Compression test
- Swap injectors between 2 and 3 to see if the misfire moves


Anything I'm missing here?

...
'97 SC1 Auto - Shaturn

REWARD EXCELLENCE!

Add to HankHill's Reputation
Rate the quality of this post and help HankHill reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
HankHill is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 10-19-2018, 11:49 AM   #2
alordofchaos
Super Member
alordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud of
 
alordofchaos's Avatar
 
Join Date: Jan 2009
Location: Central MI
Posts: 11,970
 

2002 SC2
1998 SL2
Default Re: Cyl 3 misfire at idle... couple dumb questions

Quote:
Originally Posted by HankHill View Post
But just to rule out ignition related issues, my noob questions:
- Are cylinders are numbered from pass side to driver's side . . .? (Is cyl 1 . . . closest to the passenger tire)?
Yes. If you are standing in front of the engine compartment and looking at the engine, plugs are 1-4 from left to right.

don't recall if they are numbered on the sticker on the radiator support or not



Quote:
- Both plugs connected to a given coil fire simultaneously (one of the 2 being waste spark), correct? In other words, I should be able to swap wires between terminals on the same coil in order to rule out an issue with a coil itself?
clever, can't think of why this woldnt work other than length of plugs

...
I'm not worthy to grovel in the shadow of Signmaster's wisdom

11/2016 red 2002 5 spd SC2 124k DD
7/2010 Craigslist white 1997 SC2 project
12/2008 eBay silver 1998 SL2 5 spd 102k, now 201k+ miles

REWARD EXCELLENCE!

Add to alordofchaos's Reputation
Rate the quality of this post and help alordofchaos reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
alordofchaos is offline   Reply With Quote
Old 10-19-2018, 01:35 PM   #3
fetchitfido
Super Member
fetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant future
 
fetchitfido's Avatar
 
Join Date: May 2006
Posts: 13,958
 

2001 SC2
Default Re: Cyl 3 misfire at idle... couple dumb questions

People that don't know better swap the plug wires around all the time then wonder why it's misfiring...
They have a 'polarity', a stronger primary fire and a weaker secondary fire. The secondary generally isn't strong enough to do a proper burn so the PCM responds as if it's misfiring (because it is).

All the vacuum lines come directly off the top of the throttle body, should be easy to spray carb cleaner around and find a leak, if one exists.

REWARD EXCELLENCE!

Add to fetchitfido's Reputation
Rate the quality of this post and help fetchitfido reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fetchitfido is offline   Reply With Quote
Old 10-19-2018, 01:59 PM   #4
Waiex191
Senior Member
Waiex191 has a spectacular aura aboutWaiex191 has a spectacular aura aboutWaiex191 has a spectacular aura about
 
Waiex191's Avatar
 
Join Date: Oct 2016
Location: Poplar Grove, IL
Posts: 1,178

1999 SL2
1998 SC2
Default Re: Cyl 3 misfire at idle... couple dumb questions

Sparks travel better through a vacuum than through dense air. On a 2 cylinder waste spark system, the cylinder on the compression stroke has dense air and the one on exhaust stroke does not. So, you don't get balanced current flow out of the two secondary ends of the coil, and the controls can detect if you are firing #2 or #4 for example.

...
Bryan Cotton
'99 SL2, 5SP bought new
Rebuilt at 204,067 September 2017
Engine, subframe, diff pin mod, brake lines, headliner, alternator, and so on!
'98 SC2, 5SP bought 2018

REWARD EXCELLENCE!

Add to Waiex191's Reputation
Rate the quality of this post and help Waiex191 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Waiex191 is offline   Reply With Quote
Old 10-19-2018, 02:33 PM   #5
alordofchaos
Super Member
alordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud of
 
alordofchaos's Avatar
 
Join Date: Jan 2009
Location: Central MI
Posts: 11,970
 

2002 SC2
1998 SL2
Default Re: Cyl 3 misfire at idle... couple dumb questions

Quote:
Originally Posted by fetchitfido View Post
People that don't know better swap the plug wires around all the time then wonder why it's misfiring...
They have a 'polarity', a stronger primary fire and a weaker secondary fire. The secondary generally isn't strong enough to do a proper burn so the PCM responds as if it's misfiring (because it is).
that's the reason I couldn't think of Maybe OP's car already has one switched . . .

Have a bit more time now, cleaned up the image a bit to clarify, and show spark plug wire routing (1 & 4 should run parallel next to each other, as should 2&3)
Attached Images
File Type: jpg 12900_fo_85.jpg (32.9 KB, 5 views)

...
I'm not worthy to grovel in the shadow of Signmaster's wisdom

11/2016 red 2002 5 spd SC2 124k DD
7/2010 Craigslist white 1997 SC2 project
12/2008 eBay silver 1998 SL2 5 spd 102k, now 201k+ miles

REWARD EXCELLENCE!

Add to alordofchaos's Reputation
Rate the quality of this post and help alordofchaos reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
alordofchaos is offline   Reply With Quote
Old 10-19-2018, 02:44 PM   #6
fetchitfido
Super Member
fetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant futurefetchitfido has a brilliant future
 
fetchitfido's Avatar
 
Join Date: May 2006
Posts: 13,958
 

2001 SC2
Default Re: Cyl 3 misfire at idle... couple dumb questions

Hope this doesn't confuse the OP but I did run a slightly modified '96 SC2 with the wires flipped around with 0 issue's. My dad had a bunch of '94 Cavi Z24 parts, I figured the coils might be more powerful than the S-Series (3.1 V6 vs 1.9 I4), but the catch was the polarity of them is the reverse of the S-Series so instead of the right 4123 order I used 1432. Didn't have any misfires, but the butt dyno said 0hp gain which was rather boring and not according to plan

REWARD EXCELLENCE!

Add to fetchitfido's Reputation
Rate the quality of this post and help fetchitfido reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fetchitfido is offline   Reply With Quote
Old 10-19-2018, 03:22 PM   #7
alordofchaos
Super Member
alordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud ofalordofchaos has much to be proud of
 
alordofchaos's Avatar
 
Join Date: Jan 2009
Location: Central MI
Posts: 11,970
 

2002 SC2
1998 SL2
Default Re: Cyl 3 misfire at idle... couple dumb questions

Well, that's interesting! Even if 0 gains, it's good to know for replacement if S series coils become hard to find in the future. I've never had a coil issue, but it seems like s series in JYs are slowly dwindling. hasn't been a 3rd gen coupe in my local yard for a while

Almost forgot . . . for OP, rather than switching wires, you could swap the coils and see if the problem goes with the coil

...
I'm not worthy to grovel in the shadow of Signmaster's wisdom

11/2016 red 2002 5 spd SC2 124k DD
7/2010 Craigslist white 1997 SC2 project
12/2008 eBay silver 1998 SL2 5 spd 102k, now 201k+ miles

REWARD EXCELLENCE!

Add to alordofchaos's Reputation
Rate the quality of this post and help alordofchaos reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
alordofchaos is offline   Reply With Quote
Old 10-20-2018, 12:12 AM   #8
edlee
Member
edlee will become famous soon enoughedlee will become famous soon enough
 
Join Date: Oct 2005
Posts: 381
 

1999 SL1
Default Re: Cyl 3 misfire at idle... couple dumb questions

If the Saturn Coupe uses a fragile plastic intake manifold gasket like the Saturn SL1, then that's probably it or will eventually be the cause of misfires. There are some things that just should not be made of plastic.

REWARD EXCELLENCE!

Add to edlee's Reputation
Rate the quality of this post and help edlee reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
edlee is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
two dumb questions... zwack S-Series General 1 11-01-2014 11:59 PM
Dumb questions bradbennett1981 S-Series Tech 10 08-03-2009 01:43 PM
Turbos and dumb questions..... Rossmeister Astra Tech 12 08-19-2008 02:27 PM
95 sl2 bad idle for dumb blonde wall2wall S-Series Tech 9 02-26-2007 05:10 PM
2 Dumb Questions DesertPuma Ion General 6 08-21-2002 04:31 PM


All times are GMT -4. The time now is 04:24 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
SaturnFans.com. The Saturn Enthusiasts Site.