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  1. #1
    Member bj_dove's Avatar
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    Icon4 Q for Alan S

    gday, i was told, your the man to talk to about an mi16 problem, im at home now trying to get the mi16 to fire, it lost spark a little while ago, and got it traced back to the ignition amplifier, that is now replaced and theres loads of spark, but it just turns over, and occasionally tries to fire, but wont get going.

    im just wondering if theres anything special that needs to be done to calibrate the ignition system, because we've had almost everything to do with ignition off the engine (dizzy, rotor arm, crank sensor, coil, even the main plug off the ecu!)

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    any ideas would be much appreciated

  2. #2
    Moderator Alan S's Avatar
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    Are the relays to the pump & injectors OK?
    I can't tell you exactly where they are on an Mi16 but on a 16V Cit BX they are on the inner guard drivers side; 2 of in a plastic bag.
    If they're internally corroded or if the wires to them are hard and either internally corroded or internally broken, they will give that symptom.
    From memory I don't think they can be interchanged with each other for a test due to their differing internal configuration.

    [Edit/]

    Have you checked the wires behind the amplifier also? There was recently a case in the UK where someone struck that problem and it totally stumped them. Bad wires due to deterioration could create a situation where it will fire on test but not under load. Just another thought.



    Alan S

    P.S. I'll be in & out for the next hour so either post or PM me if you need more help.
    Last edited by Alan S; 8th April 2004 at 10:34 AM.
    If it ain't broke, use a 12" shifter.....that usually does the trick!!

  3. #3
    Member bj_dove's Avatar
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    well theres plenty of fuel going in, as the plugs are wet and you can smell it.

    there is also heaps of spark, but it seems that it is intermittent, also i could tell there was spark when the plug leads were on in wrong order it gave a good old gunshot.

    so theres nothing that should need to be done as fas as timing or calibration is concerned after having all those parts off?

  4. #4
    Moderator Alan S's Avatar
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    Quote Originally Posted by bj_dove
    well theres plenty of fuel going in, as the plugs are wet and you can smell it.

    there is also heaps of spark, but it seems that it is intermittent,
    There's something not ringing true about those two statements; if you've got spark, the plugs really shouldn't be wet with petrol unless there's something amiss and the lambda is telling it that there's too much air getting through & is richening the mix up dramatically to compensate.
    Start by looking for any hoses off near the air flow meter, connections to the AFM are connected properly and go back over all the sensors you've either replaced or tested.
    If all that checks out then the lambda should be checked.

    I'm waiting on a call back from my more EFI savvy son for an opinion & will post when I hear from him.


    Alan S
    If it ain't broke, use a 12" shifter.....that usually does the trick!!

  5. #5
    Member bj_dove's Avatar
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    all hoses and connections seem to be fine on the intake side of things....

    the engine tries its heart out to start, as in it half runs on whilst cranking, almost seems like its only firing on 1 or 2 cylinders, but there is spark and fuel in all 4 cylinders.

    the battery is wearing down substantially after all this cranking, could simply a flat-ish battery cause it to not quite start?

  6. #6
    Member bj_dove's Avatar
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    just testing the crank sensor at the moment, and i can get 560ohms resistance between terminals 23 and 25 (dont know if that will make and sense to you?) but cannot get any voltage when it is cranking over, when i have been told that i should get at least 2.5v

    any thoughts?

  7. #7
    Moderator Alan S's Avatar
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    Quote Originally Posted by bj_dove
    just testing the crank sensor at the moment, and i can get 560ohms resistance between terminals 23 and 25 (dont know if that will make and sense to you?) but cannot get any voltage when it is cranking over, when i have been told that i should get at least 2.5v

    any thoughts?
    That reading is spot on; I have a portion of the service manual for an = model BX & it reckons 23 - 25 should read 490< R <600

    I think I have heard it said previously though that once the battery starts to get below a certain critical voltage, it just shuts up shop and won't allow power through to the ECU so as to not risk a blown ECU. Might be worth trying a set of jumpers onto another cars battery.
    Just remember on hook up it is + terminal first then - so as to limit the risk of a power spike.

    Alan S
    If it ain't broke, use a 12" shifter.....that usually does the trick!!

  8. #8
    Member bj_dove's Avatar
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    but what about my inability to get 2.5v from the same terminals whilst cranking?

    i dont think the battery is the problem, as i am getting spark, even if it does seem to be intermittent, so i wouldnt think that i would get a spark at all if the ecu has gone into shutdown?

    just before whilst cranking it seemed on the verge of starting, it would run on multiple revolutions in a row, just as if i were trying to start it hot, but it just then goes back to cranking over with no sign of firing

  9. #9
    Moderator Alan S's Avatar
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    I doubt that the lsoss of power there when cranking is relevant otherwise I'd imagine you wouldn't be getting the half starting caper occasionally; it would be consistent, so you may be taking yourself up a dry gully with that one.
    I recently posted a story about a problem with the wire associate with my starters solenoid and when it decided to play up, mine wouldn't start either & it was intermittent. A jumper to another known good battery made all the difference.
    I rang the young fellow but he was in the main street & driving when I spoke so he hasn't got back to me yet and I'm expecting a CD with a lot of this stuff on arriving from UK next week.
    Give the jumpers on a battery a go at least. I have to shoot off again for a little while, but post how it went & I'll see it when I get back & get an opinion off my fellow. He's off on a "petrol heads convention" at Queensland Raceway later today so I have to nab him before he takes off.


    Alan S
    If it ain't broke, use a 12" shifter.....that usually does the trick!!

  10. #10
    Member bj_dove's Avatar
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    PROBLEM SOLVED!!!!!

    well wasnt a problem really...... i hooked up another battery as you said, but it was all the same, so out of sheer desperation, i just kept cranking with the new battery, eventually it coughed itself to life and goes fine!!! it blew huge amounts of smoke for a minute or so, i think it must have been so clogged up with crap from cranking it so much that the half flat battery didnt have the grunt to bring it back to life. but i think i may have damaged an exhaust gasket or something near the headers, as some smoke was coming from there too, maybe a result of the huge backfire i mentioned earlier???

    anyway, thanks heaps for your help!


  11. #11
    Moderator Alan S's Avatar
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    Glad to hear it.

    If the gasket's blown it will make a popping sound. If it's not doing that, chances are it's either a bit of something that's spilled on the outside or at worst just a small leak that most exhausts have but we never see.
    If there's no popping noises, don't worry about it; let sleeping dogs lie and ..... have a nice 'Puggy' Easter.

    Alan S
    If it ain't broke, use a 12" shifter.....that usually does the trick!!

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