Announcement

Collapse
No announcement yet.

Timing?....

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Timing?....

    ok so my car runs great when im just driving it normal....but when i get on it and i get at about 4k or so it just boggs really bad and shutters....i dunno if it's not getting any fuel or what's going on....i did mess with the timing and i was off by a notch on the cams...but i had fixed that....i set teh timing at 20 deg....and i got on it and ran great ..then about 10 min later i was on the high way and i tried getting on it to see if any thing would happen it did the same thing just sputtering and a lil backfire....what's going on?...

  • #2
    forgot to mention one other thing!!!

    it idles at 1500 and then it'll drop to 1k every now and then.....i've tried adjusting the idle but nothing happens ..

    Comment


    • #3
      Could be a few things. They may not actually be related.

      Idle wont adjust- check the throttle body and cable tension to make sure the butterfly is fully closing.

      Sounds like it runs fine up to about 4K, except for the idle issue. Very well could be fuel. Check the filter, pump and regulator.

      If it isn't fuel then my next guess is that you are dealing with unmetered air issues. Go over every thing that connects to the intake from the filter to the cylinders to check for leaks and that all the sensors are working as they should.

      Haynes Manual and the FSM will be good friends in this.

      I'm having a hard time thinking of one item that could cause both issues. Anyone have an idea on that?
      I bet on fuel being the issue but sometimes its tough to say. :?
      Just stand back and throw money.
      Performance costs money.
      Reliable performance costs more.

      Comment


      • #4
        I'm guessing its time to change your fuel filter.
        85 Z31 6.0 LSX turbo 766whp/792wtq
        04 GTO, LS6, big cam, porting, N20... underway for summertime daily driver.

        Comment


        • #5
          has new fuel filter and i have a 3000gt vr4 pump in it but im getting a walbro soon...checked timing on motor and was off really bad and my t belt was reallly loose so i hope it's fixed now

          Comment


          • #6
            That would do it too! Yeah, allways check the basic stuff first. fuel, spark, and timing. :wink:
            85 Z31 6.0 LSX turbo 766whp/792wtq
            04 GTO, LS6, big cam, porting, N20... underway for summertime daily driver.

            Comment


            • #7
              so...

              ok so i set everything right and timing is set at 20 deg....it pulled really hard and ran good!! so i drove around a lil bit and then when i decided to try to get on it again it did the same thing!! it idles great now around 700k but it has a little popping to it...but i have no exhaust on it right now...just the elbow from the o2...and the o2 sensor is disconnected...could it be the o2 or could my pump not be pushing enough fuel...i have a fpr adjustable and it's set at about 45 right now....?

              Comment


              • #8
                popping might be caused by the really short exhaust, the o2 sensor would cause a rich situation at deceleration and low rpm cruising or idling, but a full exhaust might stop it lighting up in the pipe

                Comment


                • #9
                  Well,if it ran fine and then all of a sudden started running like crap and you found out it was the valve timing, then you fixed the valve timing and it ran great for a little bit and then all of a sudden started running like crap AGAIN.

                  I would say your tensioner keeps coming loose and your cams keep going out of time. Fix it or you will be replacing valves, and posibly pistons in no time.
                  85 Z31 6.0 LSX turbo 766whp/792wtq
                  04 GTO, LS6, big cam, porting, N20... underway for summertime daily driver.

                  Comment


                  • #10
                    Re: so...

                    JoshVG30ET wrote: ok so i set everything right and timing is set at 20 deg....it pulled really hard and ran good!! so i drove around a lil bit and then when i decided to try to get on it again it did the same thing!! it idles great now around 700k but it has a little popping to it...but i have no exhaust on it right now...just the elbow from the o2...and the o2 sensor is disconnected...could it be the o2 or could my pump not be pushing enough fuel...i have a fpr adjustable and it's set at about 45 right now....?
                    Sounds like the popping is from running rich with a short exhaust. Also, fpr is 45 with the vacuum line off, right?
                    Chuck Stong
                    300+ Parts and Performance owner
                    http://www.300-plus.com
                    2002 ZCOT president and always active member

                    Comment


                    • #11
                      ..

                      no the vacume line is on the fpr....and it's a new tensioner...and the belt stayed tight this time...when i first get in the car and if i was to punch it ....it will go with no problems...but after a lil while it'll start to bog out again if i punch it...

                      Comment


                      • #12
                        the idle surging is likely caused by the o2 sensor, even without air leaks you are getting extra fuel, the idle controls do adjust once in a while and it will idle up and down

                        but you gotta start diagnosing things, timing, compression, chts with harness resistance etc

                        Comment

                        Working...
                        X