View Poll Results: Long Crank When Hot

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  • Long Crank When Hot After stitting more then 10 Minutes

    19 61.29%
  • Long Crank All The Time

    2 6.45%
  • Short Crank All The Time

    9 29.03%
  • Short Crank Only When Cold

    2 6.45%
Multiple Choice Poll.
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Thread: Hard Starting When Hot

  1. #1
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    Hard Starting When Hot

    Is anyone else having this problem?

    I would like to gather some information about a problem I've always had with my 90.
    • After my engine warms up to normal operating temperature and if I let it sit for about half an hour, when I go to start it, I have to crank the starter for about 5-7 seconds longer then normal before the motor catches. If I was just to stop the engine for a minute or two the motor starts right up after a single crank of the starter. The problem only appears after a longer sit while still warm. If I let the engine cool down to a bone cold start it turns right over after a crank or two as it's suppose too.

    I've read other threads somewhat describing the same issue with no resolution. Has anyone fixed this problem yet?

    • I get black soot on my exhaust outlet area by the rear of the car.
    • My tempeture gage never gets as hight as the N in Normal

    Could all these problems be related? It must have something to do with a tempeture sensor but, which one?
    Last edited by rickbtbird; 07-30-2006 at 09:11 PM.


    Don't crash into a tree just to avoid a skunk!


  2. #2
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    I have the same problem with my '90 XR-7, except that it won't start at all until it cools off a bit. I did change the temp sensor near the A/C compressor with no effect. Has to be something else. I'll be interested to hear what the experts have to say...

    JD

  3. #3
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    dis module needs heatsink grease

    find it at radio shack, or a computer store. Arctic silver 5 is the best, but anything is better than nothing. dont use dielectric grease.

    or cam sensor. or a combo of both.

  4. #4
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    me too!

    rickbtbird: I've got the same problem on my 94 except for the soot and temp gauge. Here are some more observations/questions:

    • Does yours start "better" hot if you press on the gas? Mine does; it still takes way too long to catch, but I have a feeling if I didn't press on the gas it wouldn't start at all.
    • Mine revs up to ~2500 rpm once it does catch and slowly comes back down. Any other time, it doesn't exhibit this "hanging" rpm symptom; this is not an IAC or vac leak problem.
    • My temp gauge works fine; the ecu and gauge don't share temp sensors anyways. I'm 99% sure my ect sensor is fine since when I scan the computer with my scantool, it reports the right temperature. The ecu also controls idle properly based on temperature, so that also confirms the temperature circuit it working fine.
    • I should try flooring the gas sometime (which shuts the injectors down) to see how it reacts to that.
    • My problem started gradually and is getting worse!
    • My car starts super easy cold; almost too easy. Typically with fuel injection, it takes the computer a few revolutions to figure out when to fire the injectors and spark based on the crank and cam sensors. Mine fires up the instant the starter engages; I doubt the engine even makes 1 complete revolution. Is this normal?
    • I know my car has some (unidentified) issues with the EGR system. Could this be part of the problem?


    My suspicion so far is a leaking injector/injectors but I think that should only flood the cylinders affected. That should lead to a bad idle for a few seconds, not prevent the engine from starting.

    merlon: Not to doubt your advice, but I fail to see how this is a DIS overheating issue. Why would that affect the car only after it's been sitting for a while? If it's just sitting for a few minutes, it starts up fine. This also "feels" like a fuel issue, not spark/timing.

    Sorry for the long post; just attemping to cover all the bases and get this solved.

    Vince

  5. #5
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    Quote Originally Posted by Merlon
    find it at radio shack, or a computer store. Arctic silver 5 is the best, but anything is better than nothing. dont use dielectric grease.

    or cam sensor. or a combo of both.
    Been there, done that.. I've even put on two different DIS modules and it still happens.


    Don't crash into a tree just to avoid a skunk!


  6. #6
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    Quote Originally Posted by Vince_Hayduk
    rickbtbird: I've got the same problem on my 94 except for the soot and temp gauge. Here are some more observations/questions:

    • Does yours start "better" hot if you press on the gas? Mine does; it still takes way too long to catch, but I have a feeling if I didn't press on the gas it wouldn't start at all.
    • Mine revs up to ~2500 rpm once it does catch and slowly comes back down. Any other time, it doesn't exhibit this "hanging" rpm symptom; this is not an IAC or vac leak problem.
    • My temp gauge works fine; the ecu and gauge don't share temp sensors anyways. I'm 99% sure my ect sensor is fine since when I scan the computer with my scantool, it reports the right temperature. The ecu also controls idle properly based on temperature, so that also confirms the temperature circuit it working fine.
    • I should try flooring the gas sometime (which shuts the injectors down) to see how it reacts to that.
    • My problem started gradually and is getting worse!
    • My car starts super easy cold; almost too easy. Typically with fuel injection, it takes the computer a few revolutions to figure out when to fire the injectors and spark based on the crank and cam sensors. Mine fires up the instant the starter engages; I doubt the engine even makes 1 complete revolution. Is this normal?
    • I know my car has some (unidentified) issues with the EGR system. Could this be part of the problem?


    My suspicion so far is a leaking injector/injectors but I think that should only flood the cylinders affected. That should lead to a bad idle for a few seconds, not prevent the engine from starting.

    merlon: Not to doubt your advice, but I fail to see how this is a DIS overheating issue. Why would that affect the car only after it's been sitting for a while? If it's just sitting for a few minutes, it starts up fine. This also "feels" like a fuel issue, not spark/timing.

    Sorry for the long post; just attemping to cover all the bases and get this solved.

    Vince
    I was thinking along the lines of either a temperature sensor going bad. There appears to be a few different types on these cars. I've noticed some check points in my Chiltonís under emissions as to the voltage and resistance readings for the coolant temperature sensor at different temperature ranges. I should be able to make some checks today.


    Don't crash into a tree just to avoid a skunk!


  7. #7
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    check your plugs

    if you have a leaky injector that plug will be whiter than the others.

    maybe your fuel pumps heatingup and is shutting down. when was it replaced last?

    can your car drive for long periods, and then when you try to restart it it wont turn over, or does it die on you and wont turn over till it cools down?

    could be a few things, do you get power? like lights, radio??
    do your cats need replacing?

  8. #8
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    Quote Originally Posted by Merlon
    if you have a leaky injector that plug will be whiter than the others.
    I replaced the orings on all my injectors last year and the problem existed before then as well.

    maybe your fuel pumps heatingup and is shutting down. when was it replaced last?
    Fuel Pump is less then two year old and it had the problem prior to it being replaced.

    can your car drive for long periods, and then when you try to restart it it wont turn over, or does it die on you and wont turn over till it cools down?
    The car runs like a top but, after a run up to temperature, if I let it sit for 1/2 hour the starter needs to crank 5-7 seconds longer before it starts again.

    could be a few things, do you get power? like lights, radio??
    do your cats need replacing?
    NA... it's none of that.. the battery turns the starter just fine. It's the ignition of the propellant which drives the piston downward which isn't happening initially.


    Don't crash into a tree just to avoid a skunk!


  9. #9
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    Lightbulb

    long crank when warm, the cam sensor is new, that helped.
    I'm inclined to the ETS being bad so the computer thinks the engine's cold when its really warm, and the fix to get it to start is to floor the pedal, again tricking the compuiter into thinking too rich and cutting fuel then it starts.
    I have another DIS but I have not tried it yet cuz the start thing does not happen very often. I read all this on this board at some point or other.

    paul

  10. #10
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    Quote Originally Posted by thirdbird
    long crank when warm, the cam sensor is new, that helped.
    I'm inclined to the ETS being bad so the computer thinks the engine's cold when its really warm, and the fix to get it to start is to floor the pedal, again tricking the compuiter into thinking too rich and cutting fuel then it starts.
    I have another DIS but I have not tried it yet cuz the start thing does not happen very often. I read all this on this board at some point or other.

    paul
    Not that I disagree with you about that because it could very well be the problem. My temp gage always show not ever 1/4 maybe 1/8 hot. I'm guessing I should get an aftermarket gage to verify it's working. I guess my question would be that the temp gage attaches to a different sensor and if it is correct then wouldn't that lead us to a possible engine that's just running way too cool? Come to think of it I don't seem to remember my temp gage being this cool before I put on my ported manafolds and fee flowing exhaust system.
    Last edited by rickbtbird; 08-10-2006 at 08:16 PM.


    Don't crash into a tree just to avoid a skunk!


  11. #11
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    Apr 2002
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    I just had a no start hot problem. Would just crank and crank and not turn over, except for a few times when it almost (barely) felt like it might start. Fuel pressure was there (new fuel pump), I played around with the idle set screw on the tb and unplugged the iac to no avail. Tried giving it some gas while cranking an no change. Finally, after over an hour of trying, I disconnected the battery, reconnected, and it started right up!

    I do have an AR blower and chip, so this problem may be unique to those two variables as opposed to a closer to stock engine...
    SCCoA Member# 1786,
    1990 SC, AOD, 193k, Twilight Blue, bought in 1994, 1.7 AR tuned by Dave Dalke
    1994 SC, 4R70W, 139k, Teal Metallic, bought in 2014
    2014/2016 Carlisle 1st Place Winner, 94-95 SCs
    2014 Carlisle SCCOA Doug Fraleigh Best of Show Modified Trophy


  12. #12
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    hot start

    I don't think the hot start problem with these cars has anything to do with the temp sensor or DIS (In majority). I think it is a computer calibration problem.

    joenintiesc- You ever wander if getting a dyno tune would eliminate hot start problem? Then your computer would be calibrated perfectly to fit your car, eliminating any question of small problems that don't effect driveability but stick ya with dumb little things that you cannot seem to ever fix.

    Any dyno-tuned guys have hot start problems they cannot seem to fix??

    chris
    Last edited by mywhite89; 10-03-2006 at 10:43 PM.

  13. #13
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    Actually, I'm wondering if the tune on the chip may be causing the problem... Like maybe if some small thing was overlooked that is making the eec think the car is cold when I try to start it hot. But I ran codes and got a code for the ect sensor, so tomorrow I will swap it out and see what happens. Also, just as an update, I tried the battery disconnect/ reconnect trick again later on and this time it did not work.
    SCCoA Member# 1786,
    1990 SC, AOD, 193k, Twilight Blue, bought in 1994, 1.7 AR tuned by Dave Dalke
    1994 SC, 4R70W, 139k, Teal Metallic, bought in 2014
    2014/2016 Carlisle 1st Place Winner, 94-95 SCs
    2014 Carlisle SCCOA Doug Fraleigh Best of Show Modified Trophy


  14. #14
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    Quote Originally Posted by joenintiesc View Post
    Actually, I'm wondering if the tune on the chip may be causing the problem... Like maybe if some small thing was overlooked that is making the eec think the car is cold when I try to start it hot. But I ran codes and got a code for the ect sensor, so tomorrow I will swap it out and see what happens. Also, just as an update, I tried the battery disconnect/ reconnect trick again later on and this time it did not work.
    You have 60 pound injectors...Those are big injectors and very hard to precisely control at the very small pulsewidths that a hot startup requires...It's one of the downfalls of big injectors like that...Could be adjusted in the tune, but something like that will be pretty hard to get right with a mail order tune...

  15. #15
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    Hey thanks for the help . But a lot has changed in almost 3 years! lol! I didn't even have those injectors back then. I still remember when I had that problem, but damned if I can remember what the culprit was... Anyway, it wasn't a mail order tune, it was tuned on a dyno and on the road...
    SCCoA Member# 1786,
    1990 SC, AOD, 193k, Twilight Blue, bought in 1994, 1.7 AR tuned by Dave Dalke
    1994 SC, 4R70W, 139k, Teal Metallic, bought in 2014
    2014/2016 Carlisle 1st Place Winner, 94-95 SCs
    2014 Carlisle SCCOA Doug Fraleigh Best of Show Modified Trophy


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