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Car surging and stalling
Larry 735iChanged the fuel filter today and car ran better, however it is still surging and stalling when depressing accelerator. I will try to check the cat this week. Going to try to clean injectors. But remember reading about co2 sensor, where is it. Did I read that it connects via a green wire near the main relay. I have such a connector and a piece of electrical tape is inside preventing a connection. I suppose a mechanic put it there for ??? purpose. Should I connect it? This is my only car at the moment. Wife tried to retract the tires on my T-Bird by hitting a six inch high curb at 40 mph. Thanks, Larry 735i
scottieSurging and stalling...sounds like a bad vacuum leak. Did you check your air bellows? I don't think it would have anything to do with your cat. I would also leave your O2 sensor disconnected until you get a smooth idle. Start with the basics first, throttle butterfly almost closed at idle, TPS adjusted properly, Good cap and rotor, wires tested, good plugs and gapped. Test your coil, fuel pressure and temp sensor. Scottie Sharpe San Jose CA Discussion Board SYSOP 84 745i 85 535i
Larry 735iOkay Scottie: What are air bellows? I am not a mechanic by any means. Larry 735i
Jon 86 745 MSAir bellows are the accordian looking rubber tubes that run between the AFM and the throttle body. Take them off. Look at them closely and make sure there are no cracks. Look at all of your vacuum hoses and make sure that the care connected and no brakes. The O2 sensor is located under the car just rear of the rearward turn in the exhaust pipe. Jack up the drivers side of the car and look at the pipe. You will see that a wire runs from the O2 sensor in the exhaust pipe to the inside of the frame support. Follow this wire until it gets to the small sheet metal box along side of the frame. You can pull down on this box and expose the plug to the O2 sensor. Unplug the connector and run the car. I would bet that your surging goes away. Jon Jacobs 86 745i (Das Rocket) 16 psi+ Boost with Team WWW.745i.com Performance Parts
JensSounds also like your resister on your TPS is bad, replaice your TPS. Sincerely Jens
Laurie.........for the record ~ the idea to check your cat is an excellent one..... my 735 did the exact same thing when mine went bad....loss of power...surging and stalling upon acceleration etc.... What year is your car ? ~ Laurie , No CA 80' Euro 735i 78' US 733i
Larry 735i1985 Larry Larry 735i
Larry 735iHey guys: Took the air bellows off and inspected most of the vacuum hoses, trimmed the ends as they were split. Found some oil blown up into the bellows, not much. Cleaned it out and inside of the throttle body, didn't have any carb cleaner however. Saw a few cracks on the outside of the bellows, however they did not appear to go all the way through. Did notice the dipstick was not seated properly and that minor adjustment produced a smoother engine. Will change out plugs and do an oil change next week. What is the resistance I should look for when checking the plug wires? I also plan on adding injector cleaner to the fuel. Th exhaust system will probably have to wait. I need to get the compressor working, it's in the 90's most days laately. Larry 735i
Jon 86 745 MSPlug wires should be less than 7.5 ohms. All should be +- 10% of each other. Jon Jacobs 86 745i (Das Rocket) 16 psi+ Boost with Team WWW.745i.com Performance Parts