slimjim40s Posted July 2, 2004 Share Posted July 2, 2004 After first starting it up - my 4WD Hatchback w/190k miles runs just fine. However, after about 40 minutes of driving it starts to hesitate badly on takeoff and when shifting between gears. Someimes it eventually overcomes this after a while - but mostly the hesitation continues for the duration of the drive. Also - if I turn off the car for a while and then start it up again a little later - the problem begins immediately. Only when it sits for a long period of time (a couple of hours) does it drive well - for a while. Then the problem starts up again. I have replaced the fuel filter, and tried higher octane gas - but to no avail. I have looked at other similiar threads - but none seem to match my problem exactly. Can someone help me? Its very important to me. Thanks all. Link to comment Share on other sites More sharing options...
Sweet82 Posted July 2, 2004 Share Posted July 2, 2004 What year is your Subie? I have TWO fuel filters in my 82 Hatch. One under the hood and one just forward of the tank by the pump. Have you done the basic tune up? If not do it! Glenn 82 SubaruHummer 01 Forester Link to comment Share on other sites More sharing options...
slimjim40s Posted July 2, 2004 Author Share Posted July 2, 2004 Great! Thanks. Its an 84. I will look for the other filter. And I will do the tuneup. J What year is your Subie? I have TWO fuel filters in my 82 Hatch. One under the hood and one just forward of the tank by the pump. Have you done the basic tune up? If not do it! Glenn 82 SubaruHummer 01 Forester Link to comment Share on other sites More sharing options...
archemitis Posted July 2, 2004 Share Posted July 2, 2004 i wonder if its a vac leak, and at startup when the choke is still on, its ok, because of all the fuel making up for the air leaking in. maybe... Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 2, 2004 Share Posted July 2, 2004 I would hope that after 40 minutes of driving the choke would be pulled off. Just the engine heat alone would do that. Still - pull off the air cleaner cover and check to make sure it isn't partially closed or something. Sounds to me like a bad accelerator pump in the carb. The accelerator pump squirts a small jet of fuel into the carburetor throat when the throttle plate is opened to allow the engine enough fuel to increase its speed to the point where the main circuit can take over. Pull the air filter housing off, and rev the engine by hand when it's in this "hesitation" mode - see if you can see the accelerator pump working - it's near the top of the carb, and will emit a pretty obvious stream of gas as you work the throttle..... More than likely, you need to do a complete carb rebuild. Hitachi's (I'm assuming you have a Hitachi - they are more common than the Carter/Weber) are notoriously difficult to rebuild but it can be done if you are careful and take your time. GD Link to comment Share on other sites More sharing options...
oddcomp Posted July 3, 2004 Share Posted July 3, 2004 ignition stuff can do that as well when they get warm and start to not produce as much spark as it should go borrow a coil from someone and try it for a day or even maybe the module in the distributor or the ingition amplifier Link to comment Share on other sites More sharing options...
Bad Brat84 Posted July 3, 2004 Share Posted July 3, 2004 I had a similiar problem with my brat. It ran fine but one day it started the same symptoms for no apparent reason. It was related to heat and a vacuum/air leak. It was at the base of the carb at the manifold gasket. Somehow the manifold was no longer flat and when the aluminum heated up it created the gap. I confirmed this by spraying carb cleaner and starter fluid to the base of the carb and seeing an increase in engine RPM. It was hard to find as I went through the carb changeout and still no change. It might be easier to carefully spray around the carb base to see if there is any change. Try it hot and cold. It should also help identify the location of the leak. Link to comment Share on other sites More sharing options...
slimjim40s Posted July 6, 2004 Author Share Posted July 6, 2004 You guys have all provided great ideas Thanks a bunch for all of your help. I will try each solution untill I get the thing working properly. Then will write back and let youall know. I just did a complete tune-up and am about to begin testing for the problem. Conditions have to be right - hot outside, driving around town for an extended period of time, etc. Thanks all. John of Albuq. Link to comment Share on other sites More sharing options...
slimjim40s Posted July 15, 2004 Author Share Posted July 15, 2004 I gave it a good tuneup and lo & behold the symptoms subsuded substantially. I mean they are still there - but very much less pronounced. Thanks guys. You guys have all provided great ideas Thanks a bunch for all of your help. I will try each solution untill I get the thing working properly. Then will write back and let youall know. I just did a complete tune-up and am about to begin testing for the problem. Conditions have to be right - hot outside, driving around town for an extended period of time, etc. Thanks all. John of Albuq. Link to comment Share on other sites More sharing options...
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