Page 1 of 2 12 LastLast
Results 1 to 15 of 22

Thread: Car is having a hard time starting up again after its warm up

  1. #1
    Member G-Force-VR4's Avatar
    Join Date
    May 2012
    Location
    SF Bay Area
    Posts
    48

    Car is having a hard time starting up again after its warm up

    Hi,

    My car (95 VR4) can start up immediately in the morning (when cold). The issue I'm having is after I drove it for about 30 minutes or so...as long as it is fully warm up, then I turn off the car for about 20+ minutes, I will have a hard time starting it back up. If I turn off the car and start it back up right away, it will start no problem, its just happens after sitting for a period of time..around 20 minutes to 1 hour.

    The symptom I got is it will not maintain idle, I turn the ignition, it starts to idle 1200+RPM initially, and it will slowly drop to 100RPM or 200RPM and off. This process is about 5+ seconds. I started it again...while pressing the gas pedal, no throttle response at all, its like the gas pedal not having any effect at all while the RPM from around 1200 drops to 0. It struggles maintain a idle. I kept on starting the car for maybe 5 to 7 times and pressing/pumping the gas pedal, finally the gas pedal responds and I can maintain the RPM at 2000RPM while pressing the gas pedal for about 10+ seconds, then it goes back to normal idle. I do smell some gas from exhaust after all of this. This happened to me on 4 different occasions.

    Any suggestion to what is the problem and how to fix it? Thanks in advance.
    95 VR4 (15G, Intake, Exhaust)

  2. #2
    Senior Member
    Join Date
    Jun 2010
    Location
    Berkeley
    Posts
    1,853

    Re: Car is having a hard time starting up again after its warm up

    http://norcal3s.com/forum/showthread...ght=Warm+start

    The link Alan put in was interesting and thought provoking. I hotwired my fuel pump and didn't have any problem after that...until winter came back. Haven't bothered trying to figure it out though beyond that. Good luck.

  3. #3
    Deep Pocket, Shallow Boost VR-4Loco's Avatar
    Join Date
    Aug 2011
    Location
    Citrus Heights CA
    Posts
    250

    Re: Car is having a hard time starting up again after its warm up

    Not sure if this has anything to do with it. but when my cam pos sensor was going out I had almost the same issue. and sometimes car would just die while driving. and wouldn't start at all for 20 mins to 1 hour.

    Diesel wuz here

  4. #4
    Senior Member
    Join Date
    Jun 2010
    Location
    Berkeley
    Posts
    1,853

    Re: Car is having a hard time starting up again after its warm up

    Quote Originally Posted by VR-4Loco View Post
    Not sure if this has anything to do with it. but when my cam pos sensor was going out I had almost the same issue. and sometimes car would just die while driving. and wouldn't start at all for 20 mins to 1 hour.
    I'm guessing not, but worth keeping in mind if the issue progresses.

  5. #5
    Senior Member vr4exige's Avatar
    Join Date
    Oct 2008
    Location
    san jose
    Posts
    825

    Re: Car is having a hard time starting up again after its warm up

    im having this exact same problem! i thought it was my starter solenoid and got it replaced. the problem went away fro a good month but came back. now when it doesnt start, i just use my auto start and it starts. Going to install my hw fp and hope it goes away. thanks for the info guys!

  6. #6
    Senior Member
    Join Date
    Mar 2007
    Location
    Colfax CA
    Posts
    1,050

    Re: Car is having a hard time starting up again after its warm up

    Hot wire your fuel pump. I had this issue, I've never had a issue again. If I remember specifically the issue has to do with the MFI relay, hot wiring bypasses the relay with no ill effects.

  7. #7
    Original Banana Hammock chargerx3's Avatar
    Join Date
    Jul 2007
    Location
    Reno
    Posts
    2,816

    Re: Car is having a hard time starting up again after its warm up

    Used to have this problem with my car on hot days. It was rare, but i chocked it up to vapor lock.

  8. #8
    Senior Member vr4exige's Avatar
    Join Date
    Oct 2008
    Location
    san jose
    Posts
    825

    Re: Car is having a hard time starting up again after its warm up

    Quote Originally Posted by ryan94rt View Post
    Hot wire your fuel pump. I had this issue, I've never had a issue again. If I remember specifically the issue has to do with the MFI relay, hot wiring bypasses the relay with no ill effects.
    need to stop being lazy and get my how wired supra pump installed!

  9. #9
    Regular Member Spider-Dan's Avatar
    Join Date
    Feb 2008
    Location
    Suisun City
    Posts
    285

    Re: Car is having a hard time starting up again after its warm up

    I had this exact problem and it turned out to be the throttle position sensor. Hope that helps.

  10. #10
    Member G-Force-VR4's Avatar
    Join Date
    May 2012
    Location
    SF Bay Area
    Posts
    48

    Re: Car is having a hard time starting up again after its warm up

    Thanks for suggestions. I been so busy and have not had time to look at it at all. I haven't drive my VR4 close to 3 weeks now, sometimes makes me feel like if I should sell or stick with this car. I will try to do those 3 things on Jason's thread. Is there any documentation or youtube video on how to do them? I briefly searched and found some, just not sure which method is the most commonly use.
    95 VR4 (15G, Intake, Exhaust)

  11. #11
    Finally moved on... HotFlarexXx's Avatar
    Join Date
    Aug 2009
    Location
    Hayward
    Posts
    3,260

    Re: Car is having a hard time starting up again after its warm up

    Where r u locared

  12. #12
    Member G-Force-VR4's Avatar
    Join Date
    May 2012
    Location
    SF Bay Area
    Posts
    48

    Re: Car is having a hard time starting up again after its warm up

    I'm in San Fran.
    95 VR4 (15G, Intake, Exhaust)

  13. #13
    Administrator Slate Stealth's Avatar
    Join Date
    Aug 2007
    Location
    Mountain View
    Posts
    5,924

    Re: Car is having a hard time starting up again after its warm up

    Sounds like an IAC issue. As the engine heats up, the resistance in the IAC can fluctuate. When it gets out of spec, it will cause erratic idle. Testing the IAC is pretty easy, as is testing the TPS.

  14. #14
    Member G-Force-VR4's Avatar
    Join Date
    May 2012
    Location
    SF Bay Area
    Posts
    48

    Re: Car is having a hard time starting up again after its warm up

    Update..

    I did the FPCS (Fuel Pressure Control Solenoid) by-pass today, unplugged the power to the FPCS and connected a vacuum line from the plenum straight to the FPR. It is still hard to start the car. Did I do it wrong? Do I have to take FPR out too?

    If this step is done right..then on to the next step, IAC maybe.

    And Yes, my mechanical skills are not good

    Thanks
    95 VR4 (15G, Intake, Exhaust)

  15. #15
    Regular Member HardProvidence's Avatar
    Join Date
    Oct 2012
    Location
    San Francisco, Ca
    Posts
    338

    Re: Car is having a hard time starting up again after its warm up

    Tons of Fixes here http://www.3si.org/forum/f1/cant-put-my-finger-480908/ but not all a single one thats 100% guaranteed fix.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •