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 06-29-2013, 06:24 PM   #1
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default 94 SL1 Vacuum Specifications

Evening all;

I just replaced the head gasket on the kids' 94 SL1. It was leaking antifreeze pretty good, but it was running decent before I parked it a couple of months ago. Since I put it back together it has been running pretty rough and plugs become black and soot-covered in no time at all. Obvisously it's runnig very rich. To the best of my ability, and with limited tools I've diagnosed and replaced a dodgy throttle position sensor (TPS) and the manifold absolute pressure (MAP) sensor. Doing so has improved things somewhat, but the engine still idles and runs rough when it's cold or warm.

I replaced the coolant temperature sensor a couple of years ago, and I measured the resistance earlier, and it seems reasonable. I think it was about 2,000 ohms at about 90 degrees. The air temperature sensor checked out about the same too. I've also checked the operation of the Exhaust Gas Recirculation (EGR) valve with a hand vacuum pump and it seems functional as well. I also checked the oxygen sensor and that was outputting between 0.1 and 0.9 volts.

I suspect a piece of crud may have fallen in to the trottle body or maybe a vacuum hose or fitting let go after being moved after 20 years of inactivity. Anyway, before I tear into the throttle body I was looking to check the various vacuum hoses out, but I don't know how much vacuum I should expect to see at what RPM etc. I didn't see any such table in the official Saturn Service Manual at the library search, so I didn't expect it would be listed in a Haynes manual either.

So, my question is how much vacuum should I expect to see at the three hoses that originate from around the back of the carb/inlet manifold.

Thanks in advance for any guidance you can offer.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 06-30-2013, 01:56 PM   #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: 39,313
 

2003 L-Series 3.0L Sedan
Default Re: 94 SL1 Vacuum Specifications

In general, with throttle plate nearly closed and the idle air control valve automatically adjusting for idle speed, vacuum on any port behind the throttle plate at 800-900 rpm should show approximately 15-21in. hg on a vacuum gauge. The power brake vacuum port is a good place to measure vacuum - it makes no difference in port diameter as diameter controls vacuum volume and not negative pressure. Running rich has more to do with sensors than a properly maintained engine.

Your '94 uses two coolant sensors, a single wire one for the temperature gauge and a two-wire one for the pcm. The original two-wire sensor is faulty, using a plastic tipped nose that fails and causes rich running issues. The repair is replacing it with a brass one. Which sensor did you replace?
Attached Images
File Type: jpg plastic cts.jpg (41.9 KB, 1 views)
File Type: jpg coolant sensor.jpg (15.5 KB, 0 views)

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 06-30-2013, 02:56 PM   #3
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Thanks very much for your response.

It was the two-wire sensor I replaced. The connector looks very similar if not identical to the connect for the air tep sensor. It has two pins inside the that are tricky to get to. That is where I measure the resistance values and copmpared them to the table I found in the service manual. Because I've replaced a couple of these sensors before that is where I suspected the issue was originally. I even disconnected the sensor and jumpered a 1K resistor across the terminal last week when I first started dinking with it. I'm in Kansas and it was hotter than hell at the time, hence the 1K ohm resistor.

I've been messing with it again today. I disconnected and reconeected the battery to reset the ECM in case it had temporarily lost it's mind. I ran it for a couple of miutes and attempted to read the vacuum at the MAP sensor. Now that I've read your response though, I will try again at the brake vacuum hose you specified. Anyway, the point I was getting to is that after running the engine for a couple of minutes I rechecked the two-pin CTS and it was reading whatever resistance translated into 140 degrees. I also tested the MAP sensor and retested the old MAP sensor and found that the orignal was not bad either. Doh! If othing else, I'm learning a lot about the air/fuel/throttle control and vacuum systems on this car.

I'm not sure if this is relevant, but while I was looking down the throttle body when it was runningI could see gas pooling on the butterfly valve. Of course it' still rnning very rich and pumping black smoke out of the back of it.

One of the many things that is puzzling me is how this thing was running so well before I parked it. The plugs in 1 and 2 were perfect sandy-brown while 3 and 4 were a little darker, but not nearly as sooty as they are now.

Oh I forgot to mention that I replaced the PCV valve and hose as the hose was completely rotted in half. I checked that there was no blockage where the hose connects to the inlet manifold last night too. It appears they don't affect the operation of the engine that much.

I keep expecting to find something stupid that I left off, but I've checked and re-checked everything I can think of. I'll check the vacuum where you suggested and then pull the throttle body off and see if I can find anything.

Thanks again for you guidance, and keep it coming.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 03:17 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: 39,313
 

2003 L-Series 3.0L Sedan
Default Re: 94 SL1 Vacuum Specifications

The two-wire coolant sensor connector can be a sore point too, from corrosion or stretching the tiny terminals so an replacement may be needed. Any higher resistance anywhere in the coolant circuit is interpreted as a 'colder' engine. The lower the resistance the warmer the engine coolant.

Seeing fuel in the throttle body may also suggest a worn injector or pressure regulator diaphragm. This is presuming your throttle body uses a single injector on top of the throttle body? TBI's wear out and parts for rebuilding are still available.

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 06-30-2013, 04:00 PM   #5
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

I'll swing by O'Reilly or Autozone and pick up a CTS since they are so cheap. I hate to replace parts to resolve problems without really understanding the root cause first though. I hope tha fix is that easy, but I keep hearing that voice in my head asking what I screwed up, becasue it was runing fine when I parked it.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 04:08 PM   #6
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: 39,313
 

2003 L-Series 3.0L Sedan
Default Re: 94 SL1 Vacuum Specifications

No need to replace the sensor, its the connector that may also cause a higher resistance connection to skew the coolant signal, causing the pcm to run rich.

The throttle body may have a worn out injector and/or regulator diaphragm, causing rich running conditions.

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 06-30-2013, 06:13 PM   #7
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Is there a way to test the injector and/or regulator diaphragm? I suspect not with the tools at my disposal.

Also, after taking off the throttle body I noticed that the top piece that the injector was connected to was not tight to the rest of the throttle body. I tightened the 2 tork bolts and then removed the idle air control valve (IAC). Is there a way to test the IAC by apllying voltages to the different pins? The wires going into the connector appear to be paired by color. They are color coded something like:

Pin 1 -> green/white
Pin 2 -> green/black
Pin 3 -> gray/white
Pin 4 -> gray/black

I tried applying various volatges across the pin 1 and pin 2, and then pin 3 and pin 4, but did not get the plunger to move.

Thanks.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 07:38 PM   #8
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

I was thinking about your comment about the CTS connector possibly being the root of the problem. I thought I might try tracing the 2 wires back to the PCM and ohming it out from there. Then I could measure across the sensor at the pins and determine if there is a connector issue that way.

I found a resource that said that the black and yellow wires go to pins J1C03 and J1C12 respectively. I found the PCM by the drivers footwell, but I haven't been able to identify connector J1 or the numbering scheme for the connector.

Any ideas?

Thanks

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 07:42 PM   #9
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Oh it's a bit of a moot point for now since I have the throttle body off, but I couldn't find the brake vacuum hose you aluded too earlier i this thread.

Thanks.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 08:06 PM   #10
fetchitfido
Super Member
fetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud offetchitfido has much to be proud of
 
fetchitfido's Avatar
 
Join Date: May 2006
Posts: 13,499
 

2001 SC2
Default Re: 94 SL1 Vacuum Specifications

The brake vacuum hose? It's the biggest vacuum line the car use's and second in size to the coolant hose's. Most of the time it's on the left side of the booster (with master cylinder facing you) but the one pictured and everything I find on RockAuto has it on the right side (no hose attached to it, just a tag & plug where the hose would be).

I'm not sure what the specs are for the FPR but a easy test for telling if it's bad is removing the vacuum line and smelling for fuel (fuel smell in the vacuum line = bad & needs to be replaced).

An easy way to find vacuum leaks, if the engine reliably runs on it's own, is a can of carb-clean. Spray it anywhere suspected of leaking, if idle change's right after a spray that's where it's leaking from.
Attached Images
File Type: jpg 5471160-01.jpg (28.1 KB, 6 views)

...
The proper way to fix a S-Series automatic is to replace it with a 5spd O:)

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 06-30-2013, 08:29 PM   #11
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

FPR?

Thanks.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 09:19 PM   #12
autopat
Member
autopat is on a distinguished road
 
Join Date: May 2007
Location: Casa Grande, Arizona
Posts: 161

1996 SC1
Default Re: 94 SL1 Vacuum Specifications

FPR is a fuel pressure regulator. You can check the injector operation by simply running the car, and looking at the spray pattern coming out of the injector. I had the same problem, rough running, rough idle, but once off idle it was pretty smooth. I checked it after I shut off the car, and saw it drip, so I turned the key on, but didn't start it, and noticed it was dripping into the intake. Changed the injector and voila! Smooth as silk. Had a FPR go bad on a 96 SC1, but that one ran pretty good, a little hard to start when it was warm, but it also idled really high, like 2200 to 2500.


Pat

...
2010 Camaro SS
2002 SL2
2000 Suburban
1998 SL1
1996 SW2
1992 Monterey Cobra
1990 Suburban
1973 Nova SS
1966 Suburban
1965 Chevy S/W/BW

So many projects....so little time!!

REWARD EXCELLENCE!

Add to autopat's Reputation
Rate the quality of this post and help autopat reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
autopat is offline   Reply With Quote
Old 06-30-2013, 10:43 PM   #13
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Lol! The brake vacuum hose... What a noob! I don't know how I could have missed that monster. I guess I had tunneled vision and I was only looking at the throttle body.

This is looking like it is pointing towards the injector more and more. Time to start looking for parts online I think.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 06-30-2013, 11:06 PM   #14
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Pat, when you said you replaced the FPR did you just replace the diaphragm?

Thanks.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 07-01-2013, 04:39 PM   #15
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

I just replaced the fuel pressure regulator diaphragm and no change. Before I drop $75 on an injector, is there a bench test I can perform on the old one to determine if it's really worn out first?

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 07-01-2013, 06:01 PM   #16
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: 39,313
 

2003 L-Series 3.0L Sedan
Default Re: 94 SL1 Vacuum Specifications

Generally speaking, once the ignition switch is turned ON, the pcm turns on the fuel pump for 2 seconds to pressurize the lines feeding injectors. At this point, the fuel pressure should leak past any weakness in the fuel system including the injector. Look at the injector. Is it leaking from full fuel pressure or not? Starting the engine isn't necessary. While the fuel pump runs for only 2 seconds and pressure may bleed off, the initial pressure is enough to see any leaks anywhere in the pressurized lines.

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 07-01-2013, 06:46 PM   #17
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Yes I monitored the throttle body and injector while the ignition was on but did not see any leaks. After viewing a couple of YouTube videos I'm guessing that the PCM sends pulses to the injector based on how much gas it thinks the engine needs. I wonder if there is a solenoid in the injector and it can't actuate precisely enough for the signal from the PCM. Or maybe the little nozzles in the injector have worn and can't deliver such small amounts of gas as the motor requires. Thoughts?

Thanks.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 07-01-2013, 09:10 PM   #18
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

Update:

I splashed out $80 for an injector from Advanced Auto Parts since, they could get it here by tomorrow morning. In the meantime I pulled the existing injector from the throttle body. The smaller, bottom o-ring was not in great shape, but apparently not bad enough that gas would leak past it fast enough that I could detect it. I'll install the new injector in the morning and report back.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser is offline   Reply With Quote
Old 07-01-2013, 11:52 PM   #19
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: 39,313
 

2003 L-Series 3.0L Sedan
Default Re: 94 SL1 Vacuum Specifications

FYI, this link is a good reference for '91-'95 Saturns; http://www.differentracing.com/tech_articles/index.html

How many miles on the car?

Injector ON time is based on; coolant temperature, map, timing, throttle position, etc.. The pcm uses all sensor info to determine how long injectors are fired. Consider a new injector and regulator diaphragm as the equivalent of a carburetor overhaul.

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 07-02-2013, 10:41 AM   #20
Scouser
Junior Member
Scouser will become famous soon enoughScouser will become famous soon enough
 
Join Date: Jun 2013
Location: OZ
Posts: 43

1994 SL1
Default Re: 94 SL1 Vacuum Specifications

The car only has 128K on it. Really pretty low for a 94.

I'll be checking if the injector showed up shortky, and if it did I will install it and see what happens.

Thanks.

REWARD EXCELLENCE!

Add to Scouser's Reputation
Rate the quality of this post and help Scouser reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
Scouser 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
Tie rod end / LCA nut torque specifications? isoOctane S-Series Tech 7 11-17-2015 12:57 PM
Alignment specifications?? hholbein S-Series Tech 7 11-24-2010 09:09 PM
94 SL2 need toe-in specifications casterman S-Series Tech 3 12-04-2007 01:39 PM
Model Specifications freakerz General Saturn Discussion 2 11-04-2004 12:10 AM
Specifications glewisr Miscellaneous Tech 7 12-11-2003 07:22 PM


All times are GMT -5. The time now is 01:09 AM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
SaturnFans.com. The Saturn Enthusiasts Site.