Announcement

Collapse
No announcement yet.

drop in fuel milage

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    drop in fuel milage

    Last week checking under the hood I found a vacuum leak under my throttle body. Prior to noticing it I was getting between 26.7 and 27.5 mpg. Since then I have fixed the leak with some gasket sealer. The only other things I have done are check and re-gap the plugs (around .40) and check connections at the cold start valve as well as coolant sensors. (I also checked to see if my cold start was leaking, and it was not)

    Back in the car I am now getting 25.5 mpg, and it seems to be running the very same if not a little quicker. It did the complete opposite of what it should have. I unhooked the o2 sensor today and the mileage went to about 25.8-26. I just put this o2 in a few months ago. Does any of this make sense?
    Old and improved:
    Tags: None
    #2
    Isn't the plug gap supposed to be .028" ?
    What was leaking that you sealed?

    Comment

      #3
      I gapped to around .030 or so the day after, I was curious to see if anything happened.

      The gasket for my throttle body was leaking. I have one from an i car which doesnt line up perfectly on the e intake, and i didnt use sealer when i originally put it on.

      I am thinking that my coolant temperature sensor might be a cause of mileage. I also have idle problems, which fluctuate when jiggling on the prongs. Would that be a possibility? I tried to test it, but none of my tests worked. I'm having a hard time locating one from auto parts dealers though.
      Old and improved:

      Comment

        #4
        I have my coolant temp sensor unplugged, it must have been sending bad something because it almost looks burnt because it got unhooked / broke off in the past and rested on the valve cover too long.

        That's my best guess, of course I could be wrong.
        Project Thread | Instagram | Phoenix, Arizona Events Thread

        Comment

          #5
          So does your car still idle correctly? As for the sensor, do you have one that has a plastic connector, or is it one with two spade type connectors? I have literally been fighting this issue since sometime in november.
          Old and improved:

          Comment

            #6
            What I did was unplugged it, unhooked the battery. Then after eating came out put the battery back on, got it to sound a little better, then drove it for a day or two. It seemed to help me out. I really think my sensor is fryed - so I'm not really sure how it could, but I'd say try anything. Could be the O2 sensor.

            It sprays some more fuel into the intake when the engine is cold. Let me know if you car runs with it unplugged - mine has been for a few months. Idles around 700-1000 like the Bentley says. Doesn't cut out or die from what I've experinced.

            When I first got my car the rubber intake boot (before the throttle body + intake) was slit and I didn't know until I took it off. Maybe your car has developed a hole?

            The coolant temp is the connector in about the middle attached onto the valve cover on the passenger side it is the one with a clip on either side of it to snap onto the plug...I feel like this may be confusing you more then what you already know.. heh. I'll put a picture up tommorrow. Hope maybe some of this rambling may have helped.
            Project Thread | Instagram | Phoenix, Arizona Events Thread

            Comment

              #7
              isn't there 2 of them?

              Comment

                #8


                I may be wording something wrong. For some reason coolant temp sensor doesn't sound right to me. But I have been driving it without the sensor attached. It hooks up to the cold start injector and maybe for some reason sent something bad to my ecu, no idea. But I'm happy with this engine for now...

                Not exactly sure where my Bentley is... but I remember when I was having some problems I was reading through a part of the Bentley. I just can't remember what those two sensors are that are next to each other.

                Again, not sure if this will help any but you can try it. Think it may be time to put in new spark plugs/wires?
                Project Thread | Instagram | Phoenix, Arizona Events Thread

                Comment

                  #9
                  Thats the cold start valve. I was referring to the sensors on the thermostat housing. There are 4 of them. 1 is thermo time switch, 1 is coolant temperature sensor, 1 is coolant gage sensor, 1 is temperature switch for motronic.

                  For reference, in the past year I have replaced: o2, TPS, FPR, Fuel pump/filter, distributor cap/rotor, coil, spark plugs and wires, new air boot, replaced vacuum lines, swapped ECUs. All temp sensors are probably originals, and I havent replaced ICV, but swapped one and got same results. I also swapped the air flow meter, and got same results. I have been trying to combat my idle problem more than anything else. I thought the my cold start valve was leaking fuel, but i tested it, and it is dry.
                  Old and improved:

                  Comment

                  Previous template Next
                  Working...
                  X