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Engine Ghost Help - No start 900 1995

Good morning:

Just got a ‘95 940 wagon with no starting issues.

OBDI is not throwing codes.

Seems to fire a little with pedal pressed then back to dead turning over. I did get it to start with rough idle and missing but to keep it running, I had to keep the pedal moving. It would die if a kept the pedal in once spot. Once the enginer got warm, it ran perfect. Once it was turned off and sat for a while it gave the same problem.

I was following the engine coolant temp sensor ECT check steps on the FAQ links.

Question: with ECU harness attached at terminals 13 and 5, do I check for volts (should be approx 2V) and resistance(should be ~6k ohms cold) WITH KEY ON FOR BOTH CHECKS?

Also, with the ECT disconnected at engine head (DMM should read infinite ohms per Ringlee in FAQ)), does the key stay also on?

Do you know a way to check if the ECU brain is bad? I may fear this. I am hoping the engine harness has a wire break since the previous owner had a rat chewing on things.

I also have a 92 745 turbo. I know the ECU is differnt between a 95 945 non turbo. But can I swap them out just to see if the 940 car starts? Then the ECU is bad?

I am going to swap the RPM sensor and ignition control module off the 92 740 to see if the condition changes on the 95 940. I did put a new knock sensor, AMM and swapped with the coil with good one. I had these laying around from a visit to a junk yard. I love going there!


Thanks BB








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    Engine Ghost Help - No start 900 1995

    Hi,


    Because it is election day, I’m going to do something I don’t normally do, act a little conservative. It is perfectly in line with your parts replacement disposition.

    Replace the intake manifold gasket

    Verify engine compression

    Replace engine fuel

    Replace all vacuum hoses

    Verify valve clearance


    Your ECU is fine if the car runs at all. Don’t worry about the ECT until you complete the above operations.


    Goatman

    P.S. I HATE going to the junkyard!








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      Engine Ghost Help - No start 900 1995

      Maybe I gave the impression that it does start, but it really just cranks over and over.

      compression test = 180 180 190 190

      fuel volume test = 700cc per 30 seconds

      This car has 130k on it and pristine in the engine area.








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        Engine Ghost Help - No start 900 1995

        Rob,


        "Once the enginer got warm, it ran perfect." This vindicates the functionality of the fuel computer.

        Great compression readings!!!

        Continue to check and correct any vacuum leaks.

        The crankshaft position sensor is suspect.


        Goatman








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          Engine Ghost Help - No start 900 1995

          Does it have a good hot spark? You may want to clean the internal contacts in the Regina coil just to make sure all is good - it costs nothing.

          It looks like you've checked the fuel flow rate. How about psi at the fuel rail? Your 940 should have a schrader valve on the rail that you can check with a tire gauge to get a quick and dirty reading.








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            Fixed! ---Engine Ghost Help - No start 900 1995

            goatman got it!

            The crank position sensor bad. The wire insulation was crumbled under the black outer layer right before the sensor. I pulled my CPS of my good runner and the suspect car started right up.

            Life is good! Really helps to have two Volvos to swap parts - and the BB team!

            thanks







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