94 STS, Starts up, Shuts off, no useful codes, not security system
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 21
Cadillac Seville / Cadillac Eldorado Forum Discussion, 94 STS, Starts up, Shuts off, no useful codes, not security system in Past Cadillac Vehicle Discussion; Thanks in advance for any assistance, and I apologize in advance if I incorrectly posted this. My Car: 1994 Seville ...
  1. #1
    TooManyCars is offline Cadillac Owners Member
    Automobile(s): 94 Seville STS, Bradley GT/68 Ghia, 85 Fiero GT, 88 V8 Comma
    Join Date
    Apr 2013
    Location
    Henrico, VA
    Age
    35
    Posts
    9

    94 STS, Starts up, Shuts off, no useful codes, not security system

    Thanks in advance for any assistance, and I apologize in advance if I incorrectly posted this.

    My Car:
    1994 Seville STS - 4.9 Northstar
    Auto trans on floor
    Approx. 115,000 miles
    Condition: good~excellent, southern car, little or no metal corrosion/dry rot on plastics, appears to have been well maintained, has had body damage in front - repaired and repainted at one point.

    Codes: (only 1 code)
    P095 - Engine Stall Detected (History)


    Symptoms:
    Starts up smooth as glass, but shuts off approx. 2 seconds later.
    Fluttering the gas insanely fast (like your life depends on it) will keep the engine chugging poorly for 20 seconds or so until your leg gets tired. WOT or no throttle at all will both stall. Mid range throttle will also stall, no amount of throttle can seem to keep it running.

    It does not appear to be the security system. If I put tape on the key resistor (to cause an open circuit) , I get a "Wait 3 Minutes" message on the dash. I do not get this message when starting normally with the key un-taped.



    Misc. Info, I don't know if any of this matters but you never know, in no particular:
    I recently purchased this car, it had this problem when I bought it. It sounded like the security system which I speculated was a simple fix, but do not believe it is.

    The only prior information is that it died on my buddy in a parking lot at low speeds, and has had the startup/shutdown symptom ever since.

    Fuel pump has been changed out twice, to no avail.

    I do not yet have an FSM, but will be procuring one very shortly.

    I changed out the crankshaft positioning sensors to no avail.

    There is no battery in my keyfob remote.

    There is no passenger side muffler on the car at the moment

    When I open the driver door, the Security indicator lamp is blinking, but turns off when I close the door.

    Trunk hold down appears to need replacing also, and the truck is stuck open at the moment. When turning the key forward, the dash states the trunklid is open as well.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,346

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    Blinking security light is normal.

    Check for a a stuck open EGR valve. Pull it and clean the pintle valve. Be absolutely sure that it does not stick in any position and moves freely throughout it's travel. Also be sure not to allow any solvent to run int to the "can" (hold it upright, making the job a bit more of a challenge).

    Wouldn't hurt to clean the TB while you're at it.

  4. #3
    TooManyCars is offline Cadillac Owners Member
    Automobile(s): 94 Seville STS, Bradley GT/68 Ghia, 85 Fiero GT, 88 V8 Comma
    Join Date
    Apr 2013
    Location
    Henrico, VA
    Age
    35
    Posts
    9

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    Ranger, thank you very much for your input!

    Here is what I have found:

    I cleaned the EGR.. The pintle moved fine, was not stuck, but there was buildup of rust and carbon around the hole, so I cleaned that out and then used rubbing alcohol to clean the light dust and debris, being careful to not get any liquid in the cylinder. I am out of TB cleaner, do you think rubbing alcohol will suffice?

    The TB is likely clean enough to eat out of.. I wiped it out with a paper towel, but it is pretty much spotless on the inside. Accordingly, I did not clean it, think I should use cleaner on it anyway?

    New Information:
    If I clear all codes, start it up, and let it die gracefully, I get no further codes.

    If I clear all codes, start it up, flutter the gas like a mad-man causing it to barely continue to run (as previously mentioned), I get the following 2 codes:
    P073 (E073) ..................................... Intermittent Coolant Sensor Signal
    P074 (E074) ................................................ Intermittent MAT Signal

    If I then clear the codes again, start it up, let it die gracefully, I only get the original code of P095 - Engine stall detected.


    Any ideas? I have also requested my buddy to get me a trouble tree from one of his manuals to help diagnose.

    Thanks for the help!

  5. #4
    basscatt's Avatar
    basscatt is offline Cadillac Owners Master
    Automobile(s): 89 Coupe DeVille, 95 Sedan DeVille, 03 SLS, two 02 DHS's
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    63
    Posts
    9,368

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    what is the fuel pressure at the fuel rail -

  6. #5
    RippyPartsDept's Avatar
    RippyPartsDept is offline Hi, I'm Chris - Please Read My Signature
    Automobile(s): 1999 DeVille "Bianca" (white/blue, VIN-Y, 160k)
    Join Date
    Sep 2007
    Location
    Wilmington, NC
    Age
    34
    Posts
    13,946

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system



    also, try starting it with your foot through the firewall (WOT)
    once it revs up let off and see if it stays running

    i think that is how you start it in fuel dump mode where it doesn't try and get the prefect air/fuel mixture just makes sure that it will run
    Chris Heath (RippyPartsDept) is an ASE Certified GM Parts Consultant at
    Rippy is a Cadillac, Hummer, Saturn & Saab dealership - family owned and operated in Wilmington, NC since 1946
    We offer all forum members deals on parts and freight - e: parts@rippyautomotive.com ph: 800-RIPPY-22
    <-- insert standard boilerplate about posts not necessarily representing my employer, etc -->

  7. #6
    TooManyCars is offline Cadillac Owners Member
    Automobile(s): 94 Seville STS, Bradley GT/68 Ghia, 85 Fiero GT, 88 V8 Comma
    Join Date
    Apr 2013
    Location
    Henrico, VA
    Age
    35
    Posts
    9

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    It would not start at WOT.. Tried it a few times.. I am trying to figure out exactly how to check the fuel pressure now, I will update once I have a reading.

    Thanks again all!

  8. #7
    basscatt's Avatar
    basscatt is offline Cadillac Owners Master
    Automobile(s): 89 Coupe DeVille, 95 Sedan DeVille, 03 SLS, two 02 DHS's
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    63
    Posts
    9,368

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    Quote Originally Posted by TooManyCars View Post
    It would not start at WOT.. Tried it a few times.. I am trying to figure out exactly how to check the fuel pressure now, I will update once I have a reading.

    Thanks again all!
    ------------------
    I am trying to figure out exactly how to check the fuel pressure now
    you can "rent" one for free at autozone - or other big auto parts stores -

  9. #8
    TooManyCars is offline Cadillac Owners Member
    Automobile(s): 94 Seville STS, Bradley GT/68 Ghia, 85 Fiero GT, 88 V8 Comma
    Join Date
    Apr 2013
    Location
    Henrico, VA
    Age
    35
    Posts
    9

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    I bought a fuel pressure tester from Autozone.. I am a little skeptical of the readings.. At first I had no reading at all. So I pulled the fuel line off the front of the filter and it had plenty of flow (but did not check pressure there). I did manage to get the gauge to read approx. 3~10 psi after a few starts.

    I tested on the shrader valve that is located under the cruise control, is that the correct spot?

    I am thinking the gauge might be faulty, or perhaps its not engaging the nipple on the shrader valve correctly? I am going to try it on another vehicle and see if I have any luck.

    I am rather certain the fuel pump is new, if it turns out I don't have enough fuel up front, might it be a pinched line?

  10. #9
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,346

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    If you did it properly (engine at idle or at least key on to energize the fuel pump) your fuel pump is D.O.A. You should have around 40 psi fuel pressure. It will never start with 3-10 psi.

    I suspect you looked at the clean air side of the TB without opening up the throttle plate, because unless you just cleaned it, it will not be clean enough to eat out of. Open the throttle plate and take another look. You'll be surprised.

  11. #10
    TooManyCars is offline Cadillac Owners Member
    Automobile(s): 94 Seville STS, Bradley GT/68 Ghia, 85 Fiero GT, 88 V8 Comma
    Join Date
    Apr 2013
    Location
    Henrico, VA
    Age
    35
    Posts
    9

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    The TB is definitely clean.. I wiped down both sides of the plate as well as inside of the TB past the plate. I am going to see if I can test the fuel pressure at the filter as well as try the pressure gauge on another vehicle. I will update once I get that far.

    Are there any other reasons that fuel could be restricted with a new pump? FPR maybe? Would low pressure cause it to start flawlessly, just not run for too long?

    Thanks again!

  12. #11
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,346

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    No way to test the pressure at the filter. It has to be done at the threaded service port on the fuel rail.

    "New fuel pump"? You have a new pump? Where did you get this pump? Was it installed correctly? If all is OK then it is possible that you have a REALLY badly clogged fuel filter and it would have to be clogged something terrible to prevent starting.

  13. #12
    TooManyCars is offline Cadillac Owners Member
    Automobile(s): 94 Seville STS, Bradley GT/68 Ghia, 85 Fiero GT, 88 V8 Comma
    Join Date
    Apr 2013
    Location
    Henrico, VA
    Age
    35
    Posts
    9

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    My buddy put the new pump in himself.. First he tried just the pump on the original assembly, same problem. Then he tried a complete assembly, but used, same problem. Then he put in a new pump. Thats why I ask about pinched lines etc., I am curious as to the quality of his labor. The filter appears to be brand new, and judging by its location he had likely changed it when he did the pump.

    But just to clarify, the car starts wonderfully.. It starts up like the day it came off the showroom floor, one click and shes running.. It just dies after 2~5 seconds.

  14. #13
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,346

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    Sorry, I see you mentioned new fuel pump in post #1.

    I don't know. 3-10 psi should be easy to diagnose. Bad pump, clogged filter, kinked line? What else could it be?

  15. #14
    Tankboy40's Avatar
    Tankboy40 is offline Cadillac Owners Fanatic
    Automobile(s): '93 ETC (N* 120k)
    Join Date
    Jun 2012
    Location
    Akron Ohio
    Age
    41
    Posts
    320

    Re: 94 STS, Starts up, Shuts off, no useful codes, not security system

    Quote Originally Posted by TooManyCars View Post
    Thanks in advance for any assistance, and I apologize in advance if I incorrectly posted this.

    My Car:
    1994 Seville STS - 4.9 Northstar
    Am I the ONLY one who noticed this?

    a 4.9 is NOT a N* !!!!!!!

    Doesnt a TBI system run at only 7-10 PSI in perfect working order??

  16. #15
    MoistCabbage's Avatar
    MoistCabbage is offline Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    20,472
    A '94 STS has a Northstar.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting