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How many volts to injectors and how to test fuel pressure? 700

I'm troubleshooting a no start condition on an 86 745tic and I have 2 questions:

-How many volts should the injectors be getting with the ignition at the "ON" position? I assume 12V from the power pin (Green wire) and none from the ground (Gray)? I check the fuel injector ground and it has continuity/low resistance and I'm almost 100% sure I don't have a RSR (Checked almost everywhere.)

-There's no test port on the fuel rail that I can find. Would I have to make a tee that goes in between the fuel line and rail?








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    How many volts to injectors and how to test fuel pressure? 700

    First, you have a B230FT with Jetronic 2.2 system.

    It has the hall-effect sensor and no CPS on the flywheel. I don't think it has the RSR in '86. That is a biodegradable wiring harness year. Is the harness original?

    Do you have a fully charged battery when trying to start? These cars don't like weak or underpowered batteries.

    Have you checked for voltage at the fuel injectors while cranking the engine? You can use a test light on the green wire of the injector to ground. If the test light lights up while cranking then you have the injectors firing.

    Have you check the over boost switch? What about the pins on the ECU? Sometimes they corrode and have a weak connection.

    Have you tried to disconnect the AMM with the fuel inj. relay in and then starting the car?

    Have you checked the vacuum lines from the PCV system to the intake and turbo hose?








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    How many volts to injectors and how to test fuel pressure? 700

    -Cleaned ECU/other grounds
    -Injectors are getting voltage, grounds are good
    -Pulled return line off fuel rail, healthy amount of gas
    -Swapped in ECU, FPR, ignition powerstage, IAC, fuel pump relay and coil that came off a working car
    -Fuel filter installed correctly
    -Distributor cap and rotor look ok, cleaned the contacts
    -Plugs are getting nice fat spark
    -Spark plug wires are routed correctly
    -Inline fuel pump is definitely turning and staying on
    -Fuel is reaching the combustion chambers
    -Swapped the FI relay with 4 other ones
    -Nothing clogging up the intake
    -No catalytic converter to clog
    -Audible fuel pump noise and fuel relay when cranking
    -New fuel filter
    -Tachometer reads the RPM when cranking
    -Checked for vacuum leaks
    -No radio supression relay

    Tried starting it yesterday and it stumbled a couple of times and flooded. Poured some ATF into the chambers, tried again today and there was nothing besides the starter cranking.

    I still have to assemble a rig to test the fuel pressure so there's that factor still but if it's fuel it still doesn't make sense. I took off the intercooler elbow and sprayed starting fluid into the throttle body (with throttle partially open to wide open) while it was cranking and it didn't start.








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      How many volts to injectors and how to test fuel pressure? 700

      You have spark and fuel. That's 2 out of 3
      Is cam turning?
      I would check condtion of timing belt for broken teeth and verify that valve timing is correct.
      --
      David Hunter








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        How many volts to injectors and how to test fuel pressure? 700

        Forgot to mention it but yes, the cam's turning and the timing belt is okay. I'm not sure if there's anything that can block air intake.








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          How many volts to injectors and how to test fuel pressure? 700

          Any History?
          Was someone else working on it?
          Is valve timing correct?
          --
          David Hunter








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            How many volts to injectors and how to test fuel pressure? 700

            The car had been sitting for a couple of years, it ran when I bought it from the previous owner and I drove it home after I replaced the battery. I then performed the following work on the car:

            -Replaced the engine, transmission and rear end fluids
            -Removed the airbox thermostat, blocked off heater openings in airbox
            -Replaced fuel filter (hoses are on correctly, replaced the nylon hose on the pump)
            -Replaced blower motor and fuse
            -Did some welding on the passenger floor and rocker panels (Removed the negative battery cable before I did this but not before disconnecting the ECU)
            -Swapped on another set of wheels

            I didn't touch anything else in the engine bay so I was pretty confused when it didn't start. I replaced the spark plug wires and coil and cleaned the cap and rotor after this along with all the other work/checks I've done so far. I've documented most of it here in case I forgot something:

            http://forums.somethingawful.com/showthread.php?threadid=3223384&pagenumber=1

            Thanks for your help so far, I appreciate it!








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              How many volts to injectors and how to test fuel pressure? 700

              Did the donor engine have the same Flywheel? Regina vs. Bosch engines have a different flywheel and one wont run the other.....different hole pattern for CPS to read.








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              How many volts to injectors and how to test fuel pressure? 700

              You can't change the engine without touching just about everything in the engine bay. Easy to twist, tear, rip, stretch all sorts of stuff, especially wiring.
              Valve timing?
              --
              David Hunter








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                How many volts to injectors and how to test fuel pressure? 700

                Sorry, that was poorly worded. I performed an oil change and not an engine transplant.

                Finished my fuel pressure tester and with the relay jumpered I got a reading of 45 psi, which is within the 43.5 +-1.5 range.

                Swapped in an oem coil and resistor pack, replaced some vacuum hoses. Nothing.

                I forgot to put the fuel pump relay back in when I tried starting it and the engine fired up for a second, stumbled and died. This happened several times. I inserted the relay back in, tried starting it and it went back to the old "starter cranks to the end of time" state, even with my foot to the floor. Tried starting it with the relay removed again and it fired up for a second before dying.

                I've tried half a dozen fuel pump relays and I've confirmed the relay ticking and pump operation already. I really have no idea.








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                  How many volts to injectors and how to test fuel pressure? 700

                  Well then if you have fuel and air and you have spark...all thats missing is timing. Have you verified the timing belt hasnt jumped a couple teeth? Use the index marks or a timing light. After confirming proper time I would do a compression test to make sure you havent blown a HG. I havent read your whole thread but did you cleaned all the engine grounds(two on fuel rail and the ones behind battery and one below power steering pump)? Ohmed out the CPS? Jumpered RSR?








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                    How many volts to injectors and how to test fuel pressure? 700

                    I have the upper timing belt cover off right now, I'll see if I can see the crank pulley without pulling off the bottom cover.

                    The car doesn't exhibit symptoms associated with a blown head gasket (milky oil, bubbles/oil in the coolant) and I'm not sure how useful cold compression numbers would be.

                    Cleaned the fuel rail and ECU grounds, I'll check the other ones as well.

                    The car uses a Hall sensor. I cleaned the terminals and the presence of spark and a moving tach needle should rule it out. No radio supression relay.








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                      How many volts to injectors and how to test fuel pressure? 700

                      My step brother had a 740T which blew a HG just between the #2 and #3 cylinder.
                      No internal leaking just a loss of compression between the two cylinders. No oil in coolant or vice versa. Wouldnt start...just sayin you may wanna rule it out.








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                      How many volts to injectors and how to test fuel pressure? 700

                      Two thoughts:
                      I don't think that you can see the crank pulley timing mark but for this purpose you could use the O degrees timing light mark on the vibration damper rim as long as the rubber bonding has not slipped.

                      Something may be wrong with fuel pump operation. Primes but are they really running while cranking. Don't have a wiring diagram for your car but why not jumper them on and try starting. Believe this can be done at the fuses if anything like the 240.
                      --
                      David Hunter








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                        How many volts to injectors and how to test fuel pressure? 700

                        Cold compression numbers are 120+ PSI so compression is confirmed. No luck cranking it with the fuel pump bypassed on.

                        I couldn't see the timing mark on the crank pulley so I checked with the timing belt alignment diagram and from the notch on the crank it looks like it might be off a couple of teeth. When the cam gear is ~4 teeth past the alignment mark the crank notch is touching the timing belt when it should be nowhere near it. Does that make sense though?








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                          How many volts to injectors and how to test fuel pressure? 700

                          It makes no sense. The timing cannot change if the belt tension is correct and no teeth are damaged or missing on the belt and....... it was installed correctly. What is the history here? Was it ever running with the belt set that way? When cam timing is off, ignition timing is wrong as well.
                          Set the timing.
                          --
                          David Hunter








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    How many volts to injectors and how to test fuel pressure? 700

    Not sure how you have determined that you have a fuel delivery problem. You have gone from injectors to check valve. The check valve will not cause a no start.
    The 3 things to check when starting to diagnose a no start assuming engine cranks noemally
    Is the cam turning (just look in the oil filler)?
    Do you have spark at the plugs?
    Are the fuel pumps running?
    Answer to these questions will determine where the diagnosis process goes.
    What are the symptoms of the no start?
    --
    David Hunter








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    How many volts to injectors and how to test fuel pressure? 700

    Not sure how you have determined that you have a fuel delivery problem. You have gone from injectors to check valve. The check valve will not cause a no start.
    The 3 things to check when starting to diagnose a no start assuming engine cranks noemally
    Is the cam turning (just look in the oil filler)?
    Do you have spark at the plugs?
    Are the fuel pumps running?
    Answer to these questions will determine where the diagnosis process goes.
    --
    David Hunter








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    How many volts to injectors and how to test fuel pressure? 700

    All four injector plugs read .80V, the ground pulses to 1.4V when cranking.

    Battery has enough juice to power the starter so I'm going to take a look at the injector wiring and ground. Would a bad ballast resistor cause this?








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      How many volts to injectors and how to test fuel pressure? 700

      Ah, thanks! Injector voltage looks okay...

      Where is the fuel check valve located, off the main pump? I took a look at the fuel pump/lines with a mirror today and I didn't catch a glimpse of it.








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      How many volts to injectors and how to test fuel pressure? 700

      I misinformed. The 12V does not appear on the injector hot side until cranking starts. The ground side of course is pulsed to ground by the ECU.
      --
      David Hunter








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    How many volts to injectors and how to test fuel pressure? 700

    You can make a pressure gauge for testing purposes by taking the connections off of an extra fuel rail (recycling yard) and making up what you see in the photo at your local auto and hardware supply.

    Randy

    Photobucket








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    How many volts to injectors and how to test fuel pressure? 700

    Radio suppression relay.

    Inadequate fuel pressure could result in a no start condition. Both pumps are coming on, relay is working, fuel is coming out of the return line, new fuel filter, FPR came off a working car.

    I'll take a look at the injectors and post back.








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    How many volts to injectors and how to test fuel pressure? 700

    12V on both sides of injectors with key on. When you start cranking the 12 will drop some and the side going to the ECU will be getting pulsed to ground which should trigger spark, not all meters will see this pulsing.
    RSR? what is that?

    If the fuel pumps are running you almost certainly have fuel rail pressure, that pressure will stay for as long as 3o minutes after shut down. Are they running?
    --
    David Hunter








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    How many volts to injectors and how to test fuel pressure? 700

    You should see 12VDC switched at the injector connectors.
    The plus 12 is constant and the ground return is switched by the ECU.









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    How many volts to injectors and how to test fuel pressure? 700

    Look here for troubleshooting:

    http://www.brickboard.com/FAQ/700-900/EnginePerformanceSymptoms.htm
    --
    Post Back. That's whats makes this forum work.







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