'91 GT Starts then dies after starting on a warm engine....

Discussion in 'Fox 5.0 Mustang Tech' started by 91StangGT5.0, Apr 30, 2010.


  1. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    My engine seems to start up and then die every time I restart it when the engine is warm. I have no clue what the problem is and I'm not getting any codes. I can here the fuel pump running clearly......WHEN the engine is running.
    #1
  2. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    If I were you, I'd would check the Oxygen and Crank sensors. Check the Crank sensor first. That sounds like the problem. Could also be the ignition coil.
    #2
  3. loopy

    loopy New Member

    Joined:
    Apr 27, 2010
    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    southcoast mass
    it could be the pip/stator inside the distributor or the ignition control module both are cheap fixes
    #3
  4. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    I can run the car all day when the engine is cold and have no troubles at all. It's just if I turn it off after getting it to operating temp and trying to turn it back on it will die after starting unless I rev the engine quite a bit.
    #4
  5. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    I have MSD ignition....what is the pip/stator?
    #5
  6. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    Ignition module.:lock:
    #6
  7. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    I'm assuming this thing....

    [​IMG]
    #7
  8. HISSIN50

    HISSIN50 "How long does it take to get help in here? SN Certified Technician

    Joined:
    Nov 30, 1999
    Messages:
    31,148
    Likes Received:
    13
    Trophy Points:
    79
    Did you pull codes?

    After it craps out, does it always restart as long as you goose the throttle?
    #8
  9. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    I really don't want to lead you on to that alone. It could be the crank, cam, or the oxygen sensors all well. Out of those and including the ignition module, I'm 90% sure it's one of those four. Any great mechanic will be able to test all of those for you. Don't go messing around with electronics if you don't know what you're doing. My father had similar problems with various cars he owned and it always turned out to be one of those four. Here's a link below to a similar situation as yours. This should give a little more belief to what I'm saying. Good luck:p

    http://autorepair.about.com/library/faqs/bl553h.htm
    #9
  10. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    Yea I tried to pull codes but got nothing but Charcoal Canister and EGR Not Opening Properly. Nothing in ragards to ignition or fuel. Yes It will restart if I "goose" the throttle if giving it gas to keep it running is called "goosing".
    #10
  11. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    When you say Ignition module are you talking about the TFI Module that sits on the distributor?
    #11
  12. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    Yes.
    #12
  13. HISSIN50

    HISSIN50 "How long does it take to get help in here? SN Certified Technician

    Joined:
    Nov 30, 1999
    Messages:
    31,148
    Likes Received:
    13
    Trophy Points:
    79
    It's not likely to be an ignition issue.

    Has the idle screw been touched lately?
    How about the IAC?
    You might wanna test the ECT calibration.
    #13
  14. 91StangGT5.0

    91StangGT5.0 Member

    Joined:
    Oct 22, 2009
    Messages:
    162
    Likes Received:
    0
    Trophy Points:
    17
    You're speaking greek to me about ECT Calibration......I did check the IAC and cleaned it. The IAC is good to go. I did touch the idle screw back when I cleaned the IAC and set the base idle to 700 rpm
    #14
  15. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    If you can, take your car to Autozone. They can test your TFI and see if that's the problem, which I'm damn near positive it is.:cheers:
    #15
  16. HISSIN50

    HISSIN50 "How long does it take to get help in here? SN Certified Technician

    Joined:
    Nov 30, 1999
    Messages:
    31,148
    Likes Received:
    13
    Trophy Points:
    79
    It's not likely to be the TFI. If it were, his car would not run at all. It simply needs the throttle depressed manually, which is an IAC issue or a sensor that's heatsoaked and reading erroneously.

    OP, how do you know the IAC is 'good to go?' Was it tested with a scope? Sometimes cleaning them will finish them off.

    With a hot engine (when it won't idle on its own), you can note the coolant temperature and the ECT (engine coolant temperature sensor) reading and post both up. We can see if the ECT is out of calibration (which can screw with fuel trim). It's not likely to be the issue but since it takes 10 seconds to check, it's something I'd do.

    How long does it run poorly before it will idle without your assistance?
    #16
  17. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    That's a lie. LoL. TFI are very well know for causing problems like his. Just do a quick google search and see for yourself. By the way, you must not have much experience with diagnostics. Just did a quick google and bam:

    http://Please do not link to external forums/forums/5-0l-tech/57474-tfi-module.html
    #17
  18. HISSIN50

    HISSIN50 "How long does it take to get help in here? SN Certified Technician

    Joined:
    Nov 30, 1999
    Messages:
    31,148
    Likes Received:
    13
    Trophy Points:
    79
    I had chosen to be nice and diplomatic since you're new. The lack of mutual respect is disgusting.

    FWIW, we don't have cam or crank sensors. I chose not to call you out on this before.

    What's the point of that link? The TFI's are heat sensitive but they lead to a no-spark or a high-RPM spark-out. Because he CAN get it to run when it otherwise will not by simply holding down the gas pedal, the TFI is not indicated. And once it did run, the TFI would only get hotter. The car would eventually shut off and never restart.
    Failing TFI's reach a thermal limit and shut off. It sounds like he can drive as long as he wants - the trigger point for this issue is his having to restart the car after a short stop.

    I could go on but it's not my style. I normally am very tactful when I correct someone, and even more careful when I question something or someone. It's a classy approach that might be worth a shot.
    #18
  19. MikeyTodd

    MikeyTodd New Member

    Joined:
    Apr 13, 2010
    Messages:
    12
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Cayce, SC
    I'm not here to argue with you. You stated that him having a TFI issue was improbable yet clearly this is a very common problem with all makes of cars, especially Fords, trust me I know. Now, about the sensors. The mustang may not have crank and cam sensors but that doesn't make my point irrelevant. I have seen this problem lots of times and it's usually the ignition module. Just because I'm new here doesn't make me new to cars. I've had my fox for over 11 years and haven't had any problems at all besides the heater core, water pump, and the EEC going out. Never had any sensor or ignition problems yet. For you to be a considered vet, your statement about a bad TFI being improbable should of never been made. The problem is very common. By the way, the guy posted this question on April 30th. It's shouldn't take this long for somebody to answer his question.;)
    #19
  20. HISSIN50

    HISSIN50 "How long does it take to get help in here? SN Certified Technician

    Joined:
    Nov 30, 1999
    Messages:
    31,148
    Likes Received:
    13
    Trophy Points:
    79
    That makes no sense. Just because a component is a known issue doesn't mean that it's the cause of a given problem.
    #20

Share This Page