Help me out - sputters and dies

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  • Lurker27
    E30 Modder
    • Jul 2007
    • 821

    #1

    Help me out - sputters and dies

    My e30 has been a little finicky in the past with cold starts, but never ANYTHING like this. The timing belt almost went (sheared some teeth) 2 years ago, but the engine was pronounced OK then, just thought I'd give background. Once or twice I have noticed hesistation in the acceleration, and performance and gas mileage (calculated 16.7 mpg in an autotragic)

    My symptoms have started recently and have gotten worse quickly. First, the car is difficult to start. It turns over, but in the initial surge of revs, it may or may not "catch" and idle at a normal rate. If it gets to 1000 or so I can nurse it along with gas. I drove home toggling back and forth in neutral and with brake and gas to modulate my speed while feeding the car the whole time.

    Any time I am driving and I have my foot off the gas, it may stall out (loses all responsiveness and rpms slowly drop to zero, rather than all at once). Once it stalls out, it seems MUCH harder for it to start. If I attempt to start the car and it does not reach idle, quick subsequent attempts are much less likely to succeed (I have to wait 2-3 minutes before a restart is likely to succeed).

    My tank is getting low again, and I'm wondering if maybe I have water in my tank from bad gas at some point (How do you go about purging this?). I also feel like it could be something idle related - ICV sticking perhaps? My fuel pump was replaced recently, but I do not know when the plugs or injectors were (prior to ownership).

    Any insight ot this water or diagnostics I can run (planning on disconnecting the ICV and tapping it with a screwdriver to see if it sticks), would be greatly appreciated.
    '89 335is +turbo
  • Danny
    Moderator
    • Feb 2008
    • 14216

    #2
    Seafoam

    Comment

    • atomic
      R3V Elite
      • Jun 2007
      • 5691

      #3
      Could be a fuel related issue

      or

      Source a good MAF / AFM and swap out. I have seen them cause some similar problems if they are going bad.
      Last edited by atomic; 07-17-2008, 05:49 PM.

      Comment

      • Lurker27
        E30 Modder
        • Jul 2007
        • 821

        #4
        Originally posted by Danny
        Seafoam
        As a bad/watered gas solvent?
        '89 335is +turbo

        Comment

        • E30_fiend
          R3V OG
          • Apr 2006
          • 7348

          #5
          +1 on the AFM comment. My buddies mom's cabby was doing the same things. We tried putting a full tank of 91 octane in with two bottles of octane booster and still nothing. Then we took the AFM off and replaced it with a known working one and problem solved.

          Check into that and try it out if possible.



          Taylor
          Need a performance chip for you BMW? Shoot me a PM and I'll get you taken care of!!
          Taylor- Follow me on Instagram @e30_fiend


          Comment

          • Lurker27
            E30 Modder
            • Jul 2007
            • 821

            #6
            Thanks for the suggestions, guys!
            '89 335is +turbo

            Comment

            • DCColegrove
              Banned
              • Dec 2007
              • 2748

              #7
              Check for air (vacuum leaks) if you can check the fuel pressure.

              If the DME relay is more than 50K old just replace it.

              Kind of hard to diagnose just from the description you have...

              if you get this far in checking fuel press air leaks let me know...

              Comment

              • mattdk318i
                No R3VLimiter
                • Jun 2006
                • 3953

                #8
                check your FPR for good measure. Take off the vacuum line and make sure fuel isnt bypassing the diaphram and getting into the vacuum lines. That would be a definite sign that it needs to be replaced
                sigpic

                Comment

                • Aptyp
                  R3V OG
                  • Feb 2008
                  • 6584

                  #9
                  When my fiends AFM went, his car smoked like crazy.

                  I would check for vacuum leaks as well, especially that hose from valve cover to throttle. been my issue before. Intake boot? Seafoam is an awesome idea as well. Checked your plugs yet? Report back soon.

                  Comment

                  • nando
                    Moderator
                    • Nov 2003
                    • 34827

                    #10
                    bad mileage, hard starts - I would check the coolant temp sensor before anything else.

                    do you have a bentley? there are basic tests you can do with just about every system on the E30. all you need is a decent multimeter. It eliminates a lot of guessing and threads like this one. good luck on your problem.
                    Build thread

                    Bimmerlabs

                    Comment

                    • Lurker27
                      E30 Modder
                      • Jul 2007
                      • 821

                      #11
                      Unfortunately my multimeter is dead - I pulled out my bentley and I suspect the carbon canister but need to perform the electrical checks too. I'll keep this updated so it can be archived for anyone that has the problem in the future.
                      '89 335is +turbo

                      Comment

                      • Lurker27
                        E30 Modder
                        • Jul 2007
                        • 821

                        #12
                        Update - Disconnecting the ICV yielded no change in idle, so I think that's the problem.

                        I'll probably seafoam, fuel injector cleaner, and check out the O2 sensor while I'm in the mood. I need to pull the injectors, I suspect it's been running a bit rich also.
                        '89 335is +turbo

                        Comment

                        • E30_fiend
                          R3V OG
                          • Apr 2006
                          • 7348

                          #13
                          Originally posted by Lurker27
                          Update - Disconnecting the ICV yielded no change in idle, so I think that's the problem.

                          I'll probably seafoam, fuel injector cleaner, and check out the O2 sensor while I'm in the mood. I need to pull the injectors, I suspect it's been running a bit rich also.

                          Make sure you get some new o rings for the injectors. The las thing you want is one of your injectors to pop off while driving. Also, if you're running rich, I doubt its your injectors. Its possiblet but doubtful. If you're running rich its either your O2 sensor or the AFM.

                          When I was having a problem with running rich, I changed out my O2 sensor and it solved the problem immediately once it warmed up.



                          Taylor
                          Need a performance chip for you BMW? Shoot me a PM and I'll get you taken care of!!
                          Taylor- Follow me on Instagram @e30_fiend


                          Comment

                          • Lurker27
                            E30 Modder
                            • Jul 2007
                            • 821

                            #14
                            That's logical, Taylor; Thanks!
                            '89 335is +turbo

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