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


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

Reply
 
Thread Tools Display Modes
Old 01-24-2020, 09:52 AM   #1
onlinebiker
Advanced Member
onlinebiker is a glorious beacon of lightonlinebiker is a glorious beacon of lightonlinebiker is a glorious beacon of lightonlinebiker is a glorious beacon of lightonlinebiker is a glorious beacon of lightonlinebiker is a glorious beacon of light
 
Join Date: Dec 2015
Location: sw michigan
Posts: 976
Default Engine retarding ignition - part 2.

I' ve had a problem with sagging midrange power - between 50-57 mph - 99 SC2 auto trans - abs and traction control. (TC off ABS disconnected)

When first starting the car cold - the problem does not present. After it heats up (5 miles) if you accellerate slowly - you hit a dead spot - live data shows the spark drops back to 10 degree btdc or so....

Put it to the floor - great accelleration - keep speed above 57 mph (about 2300 rpm) and the advance stays up above 41 degree btdc.

Have changed knock and map sensor. No difference. No CEL.

Any ideas?

...
92 SC2
93 SC2
96 SC2
97 SL2
97 SC2
99 SC2
01 SC2 x 2 yellow
02 SC2
02 SL2
parts
2 94 SC2 parted out
2 96 SC2
98 SC2 - rusty frame minus engine.

REWARD EXCELLENCE!

Add to onlinebiker's Reputation
Rate the quality of this post and help onlinebiker reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
onlinebiker is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 01-24-2020, 11:39 AM   #2
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 43,531
 

2003 L-Series 3.0L Sedan
Default Re: Engine retarding ignition - part 2.

Shotgun answer - faulty pcm. No spare pcm to throw in suggests more diagnosing.

What brand spark plugs? What's compression numbers? (higher than stock compression suggests the pcm may reduce electronic spark timing) Any vacuum leaks? Tried a tank of premium gas? Can you determine what gear is used when the engine falls down?

The next few questions relies on a reader or scantool for specific values. What's actual coolant temperatures in everyday driving? Do coolant temps vary greatly while driving (local traffic, highway)?

...
VCX NANO

REWARD EXCELLENCE!

Add to fdryer's Reputation
Rate the quality of this post and help fdryer reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fdryer is offline   Reply With Quote
Old 01-24-2020, 01:26 PM   #3
billr
Master Member
billr is a name known to allbillr is a name known to allbillr is a name known to allbillr is a name known to allbillr is a name known to allbillr is a name known to all
 
Join Date: Jul 2013
Posts: 5,128
Default Re: Engine retarding ignition - part 2.

Does your live-data indicate "knock detected" or "knock retard" values? Just changing the knock sensor isn't enough to ensure that whole circuit is OK or that something else isn't being detected as "spark knock".

What is the MAP and rpm when you are seeing that 41 BTDC timing? 41 sounds like a lot for this DOHC type engine.

REWARD EXCELLENCE!

Add to billr's Reputation
Rate the quality of this post and help billr reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
billr is offline   Reply With Quote
Old 01-24-2020, 02:44 PM   #4
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 43,531
 

2003 L-Series 3.0L Sedan
Default Re: Engine retarding ignition - part 2.

A partial reprint from '97 SL2/SC2/SW2 service manual;

1997 Saturn SL2/SC2/SW2

Electronic Ignition (EI) System Description

The electronic ignition system on both single overhead cam (SOHC) and dual overhead cam (DOHC) engines provides spark energy to ignite the air/fuel mixture necessary for combustion. The powertrain control module (PCM) controls spark under all engine running conditions. The system components include: the PCM, electronic ignition (EI) module/coil pack, spark plugs, spark plug wires and knock sensor.

The spark dwell(On*time) and degrees ofspark advance are dependant upon engine speed, manifold absolute pressure (MAP), and engine coolant temperature (ECT). The PCM can vary spark advance from 39 degrees BTDC to 3 degrees ATDC under all engine running conditions when no spark knock is present.

IGNITION CONTROL

The primary function of the EI module is to charge and discharge the coil packs based on PCM control. The PCM has 2 control circuits, one for the 2/3 coil and the other for the 1/4 coil. The PCM uses a high controlsignal of near 5 volts to charge up the coil and a low controlsignal of near 0 volts to discharge the coil. If the coil is charged and the control signal is low, the coil willfire through its secondary towers. The secondary voltage can
reach a maximum of 40,000 volts.

...
VCX NANO

REWARD EXCELLENCE!

Add to fdryer's Reputation
Rate the quality of this post and help fdryer reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fdryer is offline   Reply With Quote
Old 01-24-2020, 09:26 PM   #5
bluesl2
Senior Member
bluesl2 is a glorious beacon of lightbluesl2 is a glorious beacon of lightbluesl2 is a glorious beacon of lightbluesl2 is a glorious beacon of lightbluesl2 is a glorious beacon of light
 
bluesl2's Avatar
 
Join Date: Jul 2005
Posts: 1,953
Default Re: Engine retarding ignition - part 2.

Are your plug wires hooked up correctly on the coils?

REWARD EXCELLENCE!

Add to bluesl2's Reputation
Rate the quality of this post and help bluesl2 reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
bluesl2 is offline   Reply With Quote
Old 01-30-2020, 07:06 AM   #6
1996SL11.9L
Senior Member
1996SL11.9L has a spectacular aura about1996SL11.9L has a spectacular aura about
 
1996SL11.9L's Avatar
 
Join Date: Sep 2009
Location: Stouchsburg, PA
Posts: 1,868
 

2002 SL1
Default Re: Engine retarding ignition - part 2.

Depending on how much carbon buildup you have on your pistons it could be the cause of your problems. I have a scangauge and have knock retard programmed into it and it was active all the time. Search google for saturns active knock retard patent and you will see it’s pretty aggressive. The timing you’re seeing is what I seen also on my 96. I actually see 44 degrees lightly loaded around 50-55mph.

My SOHC 96 had 1/16” of buildup on the pistons plus deposits stuck to the head that no matter what chemical I threw at it. The only way was when I replaced the head gasket I manually decarboned the pistons and put my clean rebuilt spare modified head on it.

It uses the idle background noise as a base line to detect knock. So if you have piston slap or a worn and noisy timing chain that will also activate knock retard.

A colder spark plug might help. Look at me thread “Not your typical spark plug question”. You can buy the Denso version at advanced auto. It is K20TR11

I even added water injection to my 96 to try and clean the carbon off the pistons. It used 1qt of oil per 1000 miles and that carbon was really baked on.

REWARD EXCELLENCE!

Add to 1996SL11.9L's Reputation
Rate the quality of this post and help 1996SL11.9L reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
1996SL11.9L 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
Head shave timing retarding a myth? hinsonracing S-Series Mods 20 10-22-2018 11:47 AM
Sources for ignition part rklein S-Series Tech 4 05-28-2013 11:01 PM
Recommended Ignition Switch part # Belarus99 Ion Tech 2 04-25-2010 11:15 PM
okay fuel and ignition diagnostics part 2 dragon370 S-Series Tech 18 08-24-2007 12:28 AM
99' SL2 ignition timing retarding off idle 8PistonSky S-Series Tech 8 04-13-2007 11:40 AM


All times are GMT -4. The time now is 12:50 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
SaturnFans.com. The Saturn Enthusiasts Site.