Announcement

Collapse
No announcement yet.

Hot start issues, will not start after warmed up

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

    Hot start issues, will not start after warmed up

    Hey guys,

    I tried doing a general internet search on this topic but it seems there are too many variables to lock it down to one specific cause, so I thought maybe you guys would know a way to pinpoint the issue.

    When I start the car for the first time, it starts and idles just fine, no issues. After driving for 10mins or so, if I shut the car off and attempt to re-start it, it's a huge struggle. The engine will crank and crank and finally turn over briefly but then die immediately. I've tried starting it with the throttle closed, throttle open, and feathering the throttle and it doesn't seem to change anything. When I was finally able to get it re-started, the idle was held rather high for a while before settling down and throttle input caused the car to rev up in a very choppy manner. I was able to drive it back home thankfully, but this is obviously going to be inconvenient if I can't sort it out quickly.

    I'm assuming the issue is due to one of three things: insufficient fueling, insufficient spark, or improper coolant temperature reading. Any idea where I should start? I just replaced the spark plugs and fuel filter, eliminated the throttle body heater and associated hoses (mess under the intake) and bled the coolant.
    1987 Toyota MR2: 20v blacktop screamer
    sigpic
    2013 Subaru BRZ: the new hotness
    1991 318is Alpine White: sold
    1989 325i Alpine White: sold

    #2
    OK, did some more research specific to the M42, sounds like it could be the FPR or the check valve. I guess it's time to start throwing parts at it...
    1987 Toyota MR2: 20v blacktop screamer
    sigpic
    2013 Subaru BRZ: the new hotness
    1991 318is Alpine White: sold
    1989 325i Alpine White: sold

    Comment


      #3
      Do a FPR test to see which one it can be. If the FPR is original, I would recommend changing it out anyways.
      Alex 88 m5 | 91 318is | 19 Subaru Ascent
      BMW Tool Rentals & Fender Roller

      Comment


        #4
        Oh, one thing I should definitely add: The car did not have this issue previously. I drove it home from New Hampshire making a couple stops along the way. It only seemed to crop up after I did the "mess under the intake" mod. Would it cause this problem if I criss-crossed the feed and return lines for the fuel? It seems like I caused the problem.

        Here's what I did:

        Removed the inlet plenum, left injectors and rail intact. Replaced gaskets, deleted TB heater plate and bypassed those heater hoses. Left the hoses to the core intact. Replaced the cracked and broken vacuum hoses. Re-assembled everything. This fixed my lack of idle due to no more vacuum leaks.

        Replaced fuel filter and spark plugs (pre-gapped OEM copper - replaced after problem arose)

        I drove it to work this morning; 17 miles. Stopped for gas after 2 miles, was able to re-start it (coolant was still reading "cold"). Drove to work with only one idle "hiccup", but otherwise fine.
        1987 Toyota MR2: 20v blacktop screamer
        sigpic
        2013 Subaru BRZ: the new hotness
        1991 318is Alpine White: sold
        1989 325i Alpine White: sold

        Comment


          #5
          Ordered a new FPR and thermostat, we'll see what happens.
          1987 Toyota MR2: 20v blacktop screamer
          sigpic
          2013 Subaru BRZ: the new hotness
          1991 318is Alpine White: sold
          1989 325i Alpine White: sold

          Comment


            #6
            I know I posted this on someone else's thread for a similar problem, but I had all these problems my fix was just unplugging the mystery plug situation found here http://www.m42club.com/forum/index.php?topic=7757.0 maybe it will help maybe it wont.
            I will add I also did the mess under the intake as well have been driving over a year now no problems
            good luck fixing it :)

            Comment


              #7
              yeah could be mystery plug, when our 318is did that it would start up okay then be really hesitant for a few seconds and clear up. check fuel pressure when engine is running vs not

              Comment


                #8
                yours plugs for sensors are wrong

                Comment

                Working...
                X