Engine stalls randomly SL1 1994 manual

Discussion in 'Saturn L-series' started by FeralserF, Aug 26, 2023.

  1. FeralserF


    Aug 26, 2023
    Likes Received:
    Hi, I have a 1994 SL1 Manual. The car has had an issue where it has stalled six times randomly over the last few months. Sometimes in hot day weather, other at noght. Since buying, the vehicle always has had an idle that when starting the car would bow slightly up and down around the 750ish rpm mark.

    I noticed three times the stalls occurred shortly after filling gas, other three times no. The car accelerates fine, doesnt overheat, never a check engine light and drives cross country, mountains without a hitch. When I start the car, the fuel pump primes no issues. What could it be?
    FeralserF, Aug 26, 2023
  2. FeralserF


    Sep 21, 2023
    Likes Received:
    Electric Ladyland
    Sounds like crank position sensor CKP.

    What is the resistance across it ( car off or sensor pulled)?

    What usually happens is that the coil inside the ckp develops a crack or discontinuity.

    The problem usually becomes heat sensitive, because as the heat rises, the coil expands ever so slightly inside the ckp and breaks the continuity of the circuit.

    No ckp signal equals no spark and no fuel injector pulses. Engine stops dead.

    30 minutes is pretty much how long it takes the ckp to cool down enough and contract such that the coil becomes continuous again and the car drives like nothing ever happened.

    It's an inexpensive fix to a truly annoying problem.

    If you want to convince yourself, keep a spark plug socket, long extension, and a 3/8 ratchet with you. The next time it happens, carefully remove a plug and ground the electrode and have someone else crank the engine. There will be no spark. Yes you could test at the coils, but that's hard to see during the day.

    Reinstall the spark plug and do not over tighten as the aluminum block is Hot.
    Derf, Sep 21, 2023
  3. FeralserF


    Aug 26, 2023
    Likes Received:
    Here is a more up to date inquiry, no it isnt the crank sensor.

    1994 Saturn SL1 5spd manual

    Okay, so car stalls randomly and the idle becomes eratic in neutral before stallout. Think you know whats wrong? think again because I doubt anyonr can help me at this point, been struggling on the side of the road for over 5 months of troubleshooting, if you have the answer I would be surprised, and you would be smarter than what is now half a dozen mechanics, but Ill take your ideas, like if you have experience with the MAF doing this, any advice is appreciated. Car runa great other than this issue, Ive driven 30,000 miles like this but the problem has gotten worse and now the car will stall everyday when the day warms past 65f or so. Here is what I replaced, I will never, ever, ever ever ever buy another saturn btw NEVER! Vehicles paint looks almost brand new after 30 years. Car seems in great shape but WTF with the random stalls.....here is what I replaced...and no there is no check engine light or codes

    Fuel Pump
    Battery cable connection
    Both ignition coils
    Spark cables
    Idle air control valve
    Crank sensor
    Throttle position sensor
    Throttle body
    Clutch hydraulics(unrelated)
    Idler pulley(unrelated)
    Drive belt(unrelated)
    Key ignition cylinder(unrelated)
    PCV and EGR hoses
    Fuel filter
    Air filter
    Air filter housing gasket

    I literally took a saw and sawed partially into the gas can and almost blew up replacing the fuel pump redneck style through the seat trunk area. Im 37 and in my entire life I have never cried and bled and shouted at the heavens more off of anything, not even close, never have the right tool no matter how many I buy. I am so exhausted and 1500 miles from anyone I know trying to fix this in the deserts, I dont know how to give up but I have literally gone insane. Advice? How does anyone decide and follow through with being a mechanic is beyond me, Im ready to give up driving if I cant fix THIS CAR.

    my last remaining ideas, let me know why theyre not it or why they might be

    MAF sensor, should I tap on it or unplug it with the car on? What electrical readings can I look for on a multimeter?

    Catalytic converter, does it get clogged when its hot? I dont smell any gas smells after I replaced the coils and ICM, but did prior very rarely

    Engine temperature sensor, this was jimmy rig soldered onto ground, I unplugged it car still runs with it plugged or unplugged

    Speed sensor, really??,

    O2 sensor, really?

    Some sort of engine compression issue or head gasket leak that only acts up when the car stalls?

    Doesnt seem like fuel injectors would fail simultaneously like this, am I wrong?

    Cam sensor?

    Some electrical cord?

    WHAT AM I missing?
    FeralserF, Jan 3, 2024
  4. FeralserF


    Aug 26, 2023
    Likes Received:
    Also, when the car stalled once when I just turned it on it wouldnt reatsrt, so I pushed it into gear to restart. When it goes out when driving ill throw it into neutral then back into gear and it force restarts before pulling to the side of the road This worked for quite a few months but now after I restart it driving as soon as I try stepping on the gas it goes full stallout. The issue has gotten worse..
    FeralserF, Jan 3, 2024
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.