I have the most complicated saturn here plz help

Discussion in 'Saturn S-series' started by FeralserF, Jan 3, 2024.

  1. FeralserF


    Aug 26, 2023
    Likes Received:
    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
  2. FeralserF


    Jan 20, 2024
    Likes Received:
    Good that you renewed the IAC valve.
    Suggestions (what maybe missing):
    1. On '94 S series, the EGR is mechanical, thermo spring activated. These require more replacement than the later electric actuators. I would renew the EGR valve.
    2. The ECT ElectricCoolantTemperature sensor is important to fuel mixture (etc.) and has lots consequences.
    Replacements are cheap. Have new one ready to thread in before remove existing (else leaks coolant)....
    It is important that the ECT connections to wiring harness are proper (polarity does Not matter) and good quality.
    3. Consider replacing the electrical Connector at the termination of wiring harness for both the IAC and the ECT.
    {Or do serious troubleshooting of those component circuits}. The harness connectors do fail....

    Be mindful that the OnBoard Diagnostics (OBD1 here) are generally first step in troubleshoot cars with computer controls. Suggest procure an OEM (Helm) Saturn MANUAL for that year of car. The Throttle Body Injection cars were Very Reliable and contributed to the good reliability reputation (only obsoleted for fuel efficiency reasons).
    If you have a Smart Phone, can get APP which (with ELM hardware interface) can yield Real Time data....
    I would renew the EGR & ECTs & FuelPressureRegulator before doing the better scan tool thing.

    I have not worked on the ThrottleBodyInjection on those year/models.
    4. I would locate the FuelPressureRegulator. The fuel pressure regulator on 96-98 can STICK and mess with injection hence Mixture (later years FPR included with filter).
    Both the IAC valve and EGR can mess with airflow (hence Mixture of fuel/air) which is critical near/at idle.
    TomM96, Jan 20, 2024
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