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91 745 running issues (regina system, normally aspirated) 700 1991

OK, so here is my problem. The car is hard to start. It requires pumping the throttle and will start rough after a try or two as long as I hold the throttle, then evens out. The idle is like 200 RPM, so I adjusted the stop for the TB butterfly so that the car idles at 550. It idles here but does hunt some, occasionally stalling. When in gear first starting off idle the car hesitates badly, then jumps out of the gate. This is if it has idled for 30 seconds or more. It also does this in traffic. At highway speeds (above 45) when letting off lightly letting off the throttle it seems to miss. I first suspected fuel pump issues as someone here suggested, but the car is also running bad rich. I see white smoke and smell gas when starting up, and it is getting terrible fuel economy. Any tips you can provide would be helpful, as I can't seem to find much info relating to the Regina system.
Thanks
keith








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    Check Throttle body- 91 745 running issues (regina system, normally aspirated) 700 1991

    I don't think the problems are specific to Regina system.

    From what you describe, I would clean throttle body, removing it from car. Then TPS (throttle position switch) can be tested easily, and be replaced if neccesary. TPS should be readjusted too. Adjustment of the throttle stop to increase idle is a clue that the problem could be throttle body and TPS.

    If there is still problems look to ICV (idle control valve aka Idle Air Control)being dirty or worn out. Some people like to clean them, but it can be damaged in the process.

    See this index page of the FAQ pages, much easier to find things:
    http://40mph.com/Brickboard_700-900_FAQ_Expanded_Index_Version/ (it links back to Brickboard.com)
    --
    I own a Volvo or Does Volvo Own Me? Try the easy to search Expanded Style FAQ Index http://40mph.com/Brickboard_700-900_FAQ_Expanded_Index_Version/








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    91 745 running issues (regina system, normally aspirated) 700 1991

    car runs fine for about 2 minutes then hesitates upon acceleration.








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      91 745 running issues (regina system, normally aspirated) 700 1991

      Throttle Position Sensor bad?
      --
      Mine: 4-940s running, 2-740 and 1-940 parts cars, and 3 1959 John Deere 630s (1 for parts), dtr1:3-940s, dtr2:1-740








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    91 745 running issues (regina system, normally aspirated) 700 1991

    See if the fuel pressure regulator on the front of your fuel injector rail holds a vaccum, (just suck on the tube hard and don't drink any gas if its leaking) ..common, and cheap, and easy

    listen to your injectors tick and see if one might be stuck open, or disconnect them 1 at a time and see if it gets better. easy, ..common, and cheap at the yards.

    A failing Engine temperature sensor will tell the computer the engine is cold and your mixture will be way rich. hard to get at, ..common, and cheap.

    A failing air intake temp sensor will have a similar effect, but these seem to last the life of the car, only check it for sludge from the flame trap. ..cheap and easy.

    A really weak regina ignition coil can fail to ignite your fuel completely and make it run way rich. use a 10 dollar spark tester at the coil wire then at a plug wire for about 20 to 30 thousand volts. ..not common on regina.

    The cold start injector could fail and make it super rich like you describe. (attatched to the underside of the intake)


    Thats a start, help me out, guys













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      91 745 running issues (regina system, normally aspirated) 700 1991

      As I delve into the FAQ, I now am wondering if these problems are not in fact fuel pump related. Is this possible? I hear it run then shut off when the key is in position II, just like it should.
      Thanks,
      Keith








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      91 745 running issues (regina system, normally aspirated) 700 1991

      I had the same problems w/my 89 regina,,,the sock on the fuel pump is probably clogged,the base of the regina coil went bad&I got an $89 replacement from advance auto.Thats was the big thing.I believe the wire through the pump sender unit is fragile&can be defective.Any other pump sender from a 740 will work.
      The throttle body has to be cleaned&throttle stop screw properly set.&also replace the o ring by the tps sender to stop an air leak there.
      lots of little things can go wrong because volvo forgot to make this cars out of rusted crap like similarly aged american autos.








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        91 745 running issues (regina system, normally aspirated) 700 1991

        I agree with blindy on the tps o-ring, but how does a poor fuel supply, via a bad sender make for a rich mixture and bad mileage?








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        91 745 running issues (regina system, normally aspirated) 700 1991

        Also check the vacuum line to the MAP sensor which is mounted on the driver's side near the firewall. If that line is cracked or off completely, the sensor will be sending the computer a "no vacuum" signal which would mimic a high load or wide open throttle condition. This would dump lots of fuel into the engine.
        That sensor could be bad as well if the vacuum line is OK.

        Once you get this sorted out I would change the oil as it will be diluted with raw gasoline from running so rich.

        Andrew S.

        '91 740 Rex Regina







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