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1995 Dodge Intrepid, no start, no spark

It came home yesterday, and this morning it refused to start. Even though I can hear the fuel pump engage, I tried a shot of starting fluid into a vacuum port on the intake. It made no difference. I pulled all six plugs and did a compression test. All were between 120 and 130 PSI except one that showed 150. That shouldn't keep it from starting. So I laid all the plugs atop the intake with their wires connected and checked for spark. None of them sparked. The check engine light is not on. What is the most likely cause for this situation?
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Comments

  • edited February 2011
    Start by finding out whether or not 12V is making it to your coil pack. If not, then your next stop should be relays and fuses.
  • edited February 2011
    I should also have mentioned that it was a little hard to start a few weeks ago, but that had largely straightened itself out. I thought it was a dirty injector and ran some BG-44K through it. That may have nothing to do with the current situation as spark didn't seem to be an issue.

    The coil pack has white numbers painted on it, leaving me to believe that it was replaced by a salvage yard unit at some point. I've only had the car three months.
  • edited February 2011
    The first step still doesn't change. If 12V is making it to the coil, then worry about the coil. Think about it - a very simple way to narrow your search by eliminating whole problem areas.
  • edited February 2011
    It's possible that the ASD relay is at fault. Here is some information from ALLDATA about it that may aid you in checking it out.

    The PCM energizes Auto Shutdown (ASD) relay by supplying relay ground, when ignition switch is in START or RUN position and PCM is receiving a reference signal from distributor.

    When the ground is applied, the relay is energized, and voltage is allowed to flow to fuel pump, fuel injectors, ignition coil, generator field winding, and O2 sensor heating element.

    When PCM does not receive reference signal from ignition system, (indicating engine is not running), then the PCM interrupts relay ground circuit and no voltage is supplied to fuel pump, fuel injectors, ignition coil, generator field winding, and O2 sensor heating element.

    The PCM controls fuel pump relay and ASD relay simultaneously, through same ground circuit.

    CIRCUIT OPERATION
    The Automatic Shut Down (ASD) relay is located in he Power Distribution Center (PDC). Power for the coil side of the relay is provided by circuit F12. This circuit is HOT in the START and RUN position, and is protected by a 10 Amp fuse in cavity 18 of the junction block.

    Power for the fuse is supplied on circuit A21 from the ignition switch. The A21 circuit receives power from the A1 circuit. The A1 circuit is protected by a 20 Amp fuse located in cavity A of the PDC.

    The Powertrain Control Module (PCM) controls the ground path for the coil side of the relay on circuit K51. This circuit connects to cavity 51 of the Powertrain Control Module (PCM) connector. It is also spliced and connects with the coil side of the fuel pump relay

    When the ASD relay is energized, the contacts internal to the relay close connecting circuits A14 and A142. The A142 circuit is spliced and provides power to the fuel injectors, generator, and the PCM.

    Circuit A14 is protected by a 20 Amp fuse located in cavity B of the PDC.

  • edited February 2011
    In his post he said he casn hear the fuel pump and has no spark at the plugs. That would rule out the ASD relay.
  • edited February 2011
  • edited February 2011
    Here is some more info. I checked for voltage at the four pin connector at the coil pack by checking each recepticle to ground and each to each of the other recepticles in turn. None showed voltage. Yes the key was on. Then I ohmed three fuses that had to do with ignition even though they looked good from the outside. They checked OK too. So I tried to start it. It fired up on the first try, but missed and ran at 2200 RPM. AS it settled down it seemed to run OK. Then it started to pop through the intake. I shut it off and restared it. It ran ok part of the time and popped part of the time. I do not hear any vacuum leaks hissing. Unless someone has a good theory about this thing, I'll probably tow it to a pro tomorrow. I should have mentioned that it is the 3.5L OHC V6.
  • edited February 2011
    Go to Autozone's website, register an email address, plug in the car's info, and go to the Repair Guides section. Find the ignition section. It should tell you which wires are which on the harness for the coil pack and how to check for voltage so that you can double-check. It may also tell you how to check the resistance on the coil pack - that's not a full check but you can at least tell if its definitely bad.

    I'd do that before jumping into the expenses of a tow truck and paying a shop for both diagnostics and then parts. If the coil pack is bad, you're probably just looking at something like $60 for a new one, and as you can see it is a breeze to install.
  • edited February 2011
    A failed crankshaft sensor will prevent your car from starting and will not necessarily set a code depending on the 'failure mode', or how it has malfunctioned. Basically the computer cannot tell if the engine is turning and will not energize the ignition system. This may not be your problem, but it's one thing to check.
  • edited February 2011
    His plug spark test was FAULTY....you need an assistant or use a creative clamp method to ground out the body of the plug in order to see arcing at the plugs.... I suspect that you do have a spark issue but at least test them properly to see first if you actually have no spark. You need to ground the body of the plug somewhere on the engine would be nice...
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