SaturnFans.com
saturnfans.com - classifieds - forums - webmail


Go Back   SaturnFans.com Forums > Models > Saturn S-Series > S-Series Tech

Reply
 
Thread Tools Display Modes
Old 10-16-2020, 09:37 PM   #21
billr
Master Member
billr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to behold
 
Join Date: Jul 2013
Posts: 5,664
Default Re: 93 sw1 crapped out injection issues

Let's regroup back at reply #13...

Are you using a voltmeter now, and have the injector (or some other load) connected to test for power and grounding pulses at the injector? If those are OK, then move on to the same circuits at the PCM connector.

I know you said you have spark, but have you checked to verify the fuel pump comes back on when cranking? That would be further proof that the CKP signal is there/OK.
billr is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 10-24-2020, 05:13 PM   #22
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

Everything is tested. Pump runs when engine is turning over ohms test injection is fine all the 12v ground lines and everything between the pcm and icm tested fine.
codyas is offline   Reply With Quote
Old 10-24-2020, 07:24 PM   #23
billr
Master Member
billr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to behold
 
Join Date: Jul 2013
Posts: 5,664
Default Re: 93 sw1 crapped out injection issues

Ohms? No, I'm asking you to check voltages (relative to ground) at the two injector terminals, with the injector or some suitable (less than 1000 ohm) load connected to the the two harness wires. At KOEO, both wires should read 12VDC, then when cranking one should remain solidly at 12VDC and the other should pulse to 0V.
billr is offline   Reply With Quote
Old 10-24-2020, 11:19 PM   #24
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

Already been through all that. Nothing happens theres a slight pulse but the injection don't do anything. I can put the injection wire to ground it sprays.
codyas is offline   Reply With Quote
Old 10-25-2020, 12:30 PM   #25
billr
Master Member
billr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to behold
 
Join Date: Jul 2013
Posts: 5,664
Default Re: 93 sw1 crapped out injection issues

We need to investigate what that "slight pulse" is; have you describe it more or even post a video/picture of what you are seeing on the meter. Try looking at that pulsing voltage using an AC range, and try looking at it with the meter set for "range hold", both in AC and DC. Evaluating those pulses with just a voltmeter can be difficult/tricky, but it is crucial to determine why the injector doesn't flow when it is (apparently) being pulsed. Either the pulses are too short, not low enough, or the injectors are bad/wrong. Try the voltmeter connected to the two injector terminals, that may show the pulses more distinctly.
billr is offline   Reply With Quote
Old 10-25-2020, 05:24 PM   #26
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

I had the pcm open and had probed the actual transistor that makes the injection work. Id have to get some numbers but i tested different things across the terminals. When it does do that slight pulse i believe there is around 1 or 2 volts sitting at the base of the transistor and it bounces maybe 1/4 of a volt there but between the collector and emitter the resistance was something like 50 ohms and would only dip very slightly. Maybe 45. I didn't write it down i don't recall the exact numbers but i believe it was around those areas. And the same test went thru 3 pcms. Idk if that injector could be wrong i believe it tested at 1 ohm on the injector and from the positive terminal on the ecm all the way to the injector pin on the ecm was about 1.5 ohms. So the wiring has a slight resistance there but shouldn't be causing a problem. Unless that injector isn't in spec. Somewhere i read 1-4 ohms or something was good. I think it tested pretty close to the original one i pulled out. Idk if theres anything that could make the pcm not run the injector? Just slowly running out of possibilities. I haven't ever had an issue like this with my other 3 saturns i had before.
codyas is offline   Reply With Quote
Old 10-25-2020, 05:28 PM   #27
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

Alot of these tests ive been using a really old analog meter. Sometimes i prefer that one to show fluctuations and stuff. So not really possible to do the "hold" deal with that one. Haha.. If i could remember where i sat the original injector i would swap that back in and see if it works. Have to clean up the terminals though. I got a other one since well 200k and the electrical plug was all gooped and melted.
codyas is offline   Reply With Quote
Old 10-25-2020, 09:01 PM   #28
billr
Master Member
billr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to behold
 
Join Date: Jul 2013
Posts: 5,664
Default Re: 93 sw1 crapped out injection issues

What is the input impedance of that analog meter? My auto/electronics experience may not be applicable here, as I started out in the 1960's with a VTVM and have use circuit-powered meters very little, and only for pretty much non-electronics purposes.

It sounds like your '93 SOHC PCM is considerably different from my '94 DOHC unit. The injector drivers (four of them) in mine are buried in proprietary 15-pin SIPs. Without datasheets for those SIPs, I have little clue as to which pins are which; doubt I could reliably tell even if they are BJT or FET devices.

I also question the usefulness of C-E resistance measurement to check for driver pulsing. To pulse, the PCM needs to be powered up. Any active power in that driver output circuit would greatly influence the resistance reading.

Are you willing to back out of the PCM "rabbit hole" for a while and do the voltage checks I asked for at the injector connector? If not, I should bow-out here. Without your cooperation, my efforts here will be frustrating to me; and probably you too.
billr is offline   Reply With Quote
Old 10-25-2020, 10:08 PM   #29
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: 44,412
 

2003 L-Series 3.0L Sedan
Default Re: 93 sw1 crapped out injection issues

It was suggested to test fuel pressure back in post#4. With 200k miles, no one knows when fuel pumps fail. Maybe now's the time after exhausting several avenues; replaced/tested injector with 12v directly, replaced pcm twice, checked continuity between injector and pcm, etc. With a single throttle body injector incorporating a pressure regulator that does wear out (from other members posting worn out regulator diaphragm), you're left with no idea if the fuel pump still runs and outputs pressure after 200k miles/27 yrs or not, if the tbi regulator is faulty or not and if the fuel filter is blocking fuel pressure and flow.

As mentioned previously, enabling the fuel pump manually is simple. Locate the fuel pump relay, remove it and familiarize yourself with relay pinouts on the relay. Insert a short jumper wire or paper clip into relay socket terminals 30 and 87. This sends 12v immediately to power the fuel pump regardless of ignition switch position. Presuming the fuel pump fuse isn't blown, you may hear a quiet hum/hiss sound of the fuel pump. You can try starting immediately (someone turning the ignition key) while looking down the tbi for fuel spray or loosen a fuel line fitting to see if fuel pressure forces fuel out. Any fuel flow at this point doesn't tell you pressure, just fuel at a loosened fitting.

Several members with TBIs see fuel spraying out with engine starting or idling when troubleshooting rich fuel problems. These instances were about worn out injectors not closing and/or built in pressure regulator fault.
...
VCX NANO
fdryer is online now   Reply With Quote
Old 10-26-2020, 04:18 AM   #30
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

This meter runs on a 9 volt for some things and 1.5 D battery for other things. Not sure about specs further than that. I believe only the voltage and current tests are circuit powered on it. The only reason i checked resistance over the transistor is to see if it was actually pulsing. Which its a very insignificant change. Not enough to pulse the injector. All fuel related things have checked out good. Fuel pressure pump works just fine.
codyas is offline   Reply With Quote
Old 10-26-2020, 01:12 PM   #31
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: 44,412
 

2003 L-Series 3.0L Sedan
Default Re: 93 sw1 crapped out injection issues

Some circuits electronically switch ground instead of 12v. If both injector wires were tested for continuity to pcm, is the pcm grounded? There should be ast least one electrical ground terminal on the pcm if not several. Then equipment ground, a shield ground or Faraday cage against rf noise that may be picked up in electronics, interfering with circuitry.

If I'm not mistaken, tbi and multi point injectors electronically switch ground with injectors supplied with 12v power when ignition is turned on, hence measuring 12v on both sides of injector connections to ground. If pcm ground becomes corroded or faulty, the power transistor cannot switch on ground to compete the injector circuit on each pulse.
...
VCX NANO
fdryer is online now   Reply With Quote
Old 10-26-2020, 03:09 PM   #32
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

Grounding was tested. Pcm case to car body less than 1 ohm across. With pcm hanging not connected to the car. Theres 2 main grounds on pcm on mine both checked out. And yeah 12v on either end of injector. Very small amount of current passing thru that transistor. Which i believe is normal and tells me the circuit is complete anyway. Im not sure if theres a possibility of half shot wiring that will test ok but with a potential current draw Maybe a corroded connection could be a point of issue. I am tempted to add a jumper to ground and 12v see if anything happens. It did sputter over once when i smacked the fuse box. I think i was checking fuses and when i smacked on 1 to get them in all the way when i cranked it again it sputtered over and quit again. Possible issue? I mean idk how much current the pcm takes but heck im about ready to rip the whole electrical system out and start over. Ive never had an issue that wasn't fixed after throwing maybe 3 parts at it. Im up to like 5 parts already with no change. And hours of diagnostics checking over everything.
codyas is offline   Reply With Quote
Old 10-26-2020, 04:40 PM   #33
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: 44,412
 

2003 L-Series 3.0L Sedan
Default Re: 93 sw1 crapped out injection issues

My guesstimate is around one amp for the pcm but injector switching transistor may run several amps but in pulses. Your pcm fuse(s) tells you maximum amperage. In general, current draw for engine computers are low amperage for switching power to relay solenoid coils. Sensors operate on milliamps. Power circuits draw current depending on what power they need.

On a side note, one L300 owner went thru hoops trying to figure out why his engine wouldn't startup. After some back and forth exchanges, it was determined his ecm, normally bolted on top of an intake manifold runner (central manifold with two runners feeding both sides of the V6) wasn't completely mounted. One screw loosely held the ecm on and prevented engine starting/running. Once bolted correctly, the grounded ecm operated perfectly. He was unfamiliar with grounding electronics had the ecm loose while troubleshooting.
...
VCX NANO
fdryer is online now   Reply With Quote
Old 10-26-2020, 05:33 PM   #34
codyas
Member
codyas is on a distinguished road
 
Join Date: Jun 2013
Posts: 181
 
Default Re: 93 sw1 crapped out injection issues

I may try something. The way the pcm mounts on a 93 does not really have a good ground if any grounding exists at all. Theres plastic guides and a push in thing. Its like a screw but just clicks up in and holds it in place. The grounding it has seems ok but it is old and possibly corroded within a crimp fitting in the harness terminals. Suppose its worth a shot. Just seems odd . if its not needing much power. It just uses a little power to switch the transistor. And the transistor just sinks the current to ground. The transistor operation seems fine idk if something within the pcm is not getting power to do that or if something is just preventing the pulsing. I cranked it over with the coolant and tps disconnected. I have had issues with failed temp sensors thinking it was much hotter than it was. But it usually still stumbled and tried to run. This issue now is just getting to me. It ran. Died at a redlight. After a little bit it started idled fine. Gave it some gas and it quit again. I mean a failing ground could be a potential issue. . right now i kinda hope its something dumb like that. Running out of ideas
codyas is offline   Reply With Quote
Old 10-26-2020, 06:06 PM   #35
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: 44,412
 

2003 L-Series 3.0L Sedan
Default Re: 93 sw1 crapped out injection issues

Basic Ohm's law: E=I x R. Current can be determined with injector resistance and voltage. Using 13 vdc, divide 13 by injector resistance to determine current draw.

Many are unfamiliar with current flow. Current flows from negative to positive. Case in point: every alternator has a fusible link wire calibrated to around 25 amps while most alternators are rated anywhere from 75-300 amps. The fused side of alternators is thru this fusible link wire, connected to a side terminal, limits the input current but not the output current. All current flows from the alternator case/frame bolted to the engine block. Engine block ground goes to chassis ground then to battery negative. Anyone assuming high charging current goes thru the small fusible link wire would be wrong - the fuse would burn up. Going thru case ground to engine block back to battery negative allows easier current flow for recharging the battery as well providing all the electrical needs of every vehicle.

Injectors are pulsed on and off. The on time pulse varies to provide precise fuel shots on every intake stroke. Short pulse = short shot of fuel, long pulse = more fuel per injector pulse and everything in between. Pulse time is seen with an oscilloscope.
...
VCX NANO
fdryer is online now   Reply With Quote
Old 10-26-2020, 07:35 PM   #36
billr
Master Member
billr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to beholdbillr is a splendid one to behold
 
Join Date: Jul 2013
Posts: 5,664
Default Re: 93 sw1 crapped out injection issues

Well, I intended to just watch this thread from now on, but that description of the charging system is so misleading I just gotta say...

Nearly all alternator circuit certainly does go through the fusible link. That is, all but the 5A or so for energizing the field and powering the regulator.

Yes, all alternator current also goes through the case/ground connection; it has to be a "closed loop", another fundamental of electricity. By the way, electrons flow - to +, but current flow is the opposite (+ to -)
billr is offline   Reply With Quote
Reply

Bookmarks


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
2006 Ion 2 Secondary Air Injection System Issues Jeriath Ion Tech 3 10-31-2013 03:08 PM
"Hydrogen Power" vapor injection / water injection - worth it? terpodion S-Series Mods 9 07-10-2012 12:35 AM
Whoops, I crapped my pants golftango Aura General 6 06-28-2010 08:10 PM
oxygen sensor crapped out...where/what to buy? colonelhogan44 S-Series Tech 7 12-25-2006 03:04 PM
Northern Ontario was crapped on!!! craig2000LW2 General Saturn Discussion 10 11-23-2000 02:04 PM


All times are GMT -4. The time now is 01:55 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
SaturnFans.com. The Saturn Enthusiasts Site.