1995 Chevy Monte Carlo, 3.1, automatic, approx. 129,000 miles

We just bought a 1995 Monte Carlo a little over 2 weeks ago and already we are having ALOT of problems so I hope someone can answer my questions. We have already replaced the turn signal switch, and the rear defogger does not work, the odometer isn’t working, and the gas gauge jumps around between 1/2 tank and full no matter how much it has in it, but the major problem is this. When you start the car sometimes it would hesitate a bit before turning over. Once it’s running it would run smooth but after you get out on the road after just a couple miles it starts to sputter and cut out like it wants to die. Sometimes it will and sometimes it won’t. When it does it will start again but it doesn’t take long to start cutting out again. It acts like it’s not getting fuel, like maybe it’s the fuel pump or clogged injectors, so we changed the filter and used some injector cleaner but that has not helped. Today we were not more than 4 or 5 miles from home when it died for good and now it will not start at all. When it died the last time, there was a small pop, like a muffled backfire, not from the back of the car but it sounded like it was directly under the front seats and the engine started idling very rough before it stopped and wouldn’t turn over at all. Like I said it was acting like it’s not getting any fuel so maybe it’s a fuel pump or bad injectors, but from what I have read, it could possibly be the ignition switch not registering the transponder chip in the key. My question is this. How can my husband test to see if it is any one of these problems or something else entirely without going to a garage. There is no money in the budget for that unfortunately. There are no lights on the dash (check engine, anti-theft) but with the gauge issues that may not mean anything. If someone could address one or even better all of our problems we would be forever grateful. Thank you in advance.

2 thoughts on “1995 Chevy Monte Carlo, 3.1, automatic, approx. 129,000 miles”

  1. No Start Diagnostics

    1. Rear Defogger: First Check the 3 fuses that are tied to this circuit. Fuse # 16, 24 and 15.
    If they are OK, then Check the Rear Window Defog Relay(not all models are equipped).
    If that checks out, then check for power going to and then from the Rear Defogger Switch.
    If that checks out, check for power at the Grid at the rear window itself. (repair as needed)

    2. Odometer not working: If the speedometer is working but the odometer is not, the Instrument cluster/meter will need to be replaced.

    3. The Gas Gauge: The fuel sending unit is located on the side of the fuel pump assembly and comes as part of the fuel pump assembly. The sending unit contacts are worn out. The Fuel Pump Assembly will have to be replaced to correct the problem.

    4. Will not start: The most likely cause to your problem is the Ignition Control Module from what you have described. I believe the ignition control module has been breaking down and would cause a “NO SPARK” condition. This would allow unburnt fuel into the exhaust and when it did spark that one last time made the loud pop sound under your seat. This is common.

    You may want to check to see if you can spark and or fuel. If you see that you have spark, you may try spraying starting fluid into the air filter to see if it will start. If it does, you know you have a fuel related issue and at this point you need to replace the fuel pump anyway to repair the fuel gauge operation. Hope this gets you started in your repairs.

    To test fuel pump:
    1.Connect pressure gauge J–34730–1, or equivalent, to fuel pressure test point on the fuel rail. Wrap a rag around the pressure tap to absorb any leakage that may occur when installing the gauge.
    2.Turn the ignition ON and check that pump pressure is 24–40 psi. (165–276 kPa)
    3.Start the engine and allow it to idle. The fuel pressure should drop to 28–32 psi (193–221 kPa) due to the lower manifold pressure.
    NOTE: The idle pressure will vary somewhat depending on barometric pressure. Check for a drop in pressure indicating regulator control, rather than specific values.

    4.If the fuel pressure drops, check the operation of the check valve, the pump coupling connection, fuel pressure regulator valve and the injectors. A restricted fuel line or filter may also cause a pressure drip. To check the fuel pump output, restrict the fuel return line and run 12 volts to the pump. The fuel pressure should rise to approximately 75 psi (517 kPa) with the return line restricted.
    5.Before attempting to remove or service any fuel system component, it is necessary to relieve the fuel system pressure.

  2. Thank you so much for answering all of my questions! You were a huge help. It is the Ignition control module. The fuel pump is working fine but we are going to replace it anyway in the near future to fix the gauge issue. And thanks for using plain simple English! I’m not a mechanic but I have owned so many used car over the years that I can pretty much take an educated guess at what the problem is and alot of mechanics try to talk down to you like you wouldn’t understand. Your site is deffentaly going into my favorites list!!

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