Ign Coil/ Injector Tester

Discussion in 'The Projects Forum' started by debe, Jan 19, 2011.

  1. debe

    Thread Starter Well-Known Member

    Sep 21, 2010
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    This is a little tester I built some years ago & thaught might be of interest to Electronicly minded mechanics. It doesnt use many parts, Q1 is salvaged from a vehicle ECU that had 3 Ign coil switching transistors with in built damping. If these are not avalable you could use MJH10012 darlington with 3 x 75V 3W zenners from the collector to emmiter. There is also a lead fitted from the base of the driver transistor to drive things such as electronic speedos or some electronic driven IGN modules. In the pics it is shown driving various Ign coils & an Injector. The CDI ign module is from a brush cutter. To drive these you need a Ecore, The one i used is from a very old transistorised car radio, it was an audio O/P stage. Also handy for finding where there is a breakdown of insulation on IGN leads. The type that is deep in the cylinder head. In the pic there is a spark plug in the end of the lead with a very wide gap. You then use a grounded lead run over the insulating boot, the spark will jump through the breakdown point.
     
    Last edited: Jan 20, 2011
  2. debe

    Thread Starter Well-Known Member

    Sep 21, 2010
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    The other pics that didn fit.
     
  3. Makerdino

    New Member

    Jan 19, 2011
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    0
    Nice tool and good use of salvaged parts. I like that. :)
     
  4. debe

    Thread Starter Well-Known Member

    Sep 21, 2010
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    Some pics of my Injector test setup the fuelpump, pressure regulator & piece of fuel rail are all from wrecked cars. The fuelfilter & hoses were new. I mainly use it for checking fuel spray patterns & shut off leakage. Have used it to recover blocked injectors that the professionals said were not recoverable. Iremoved the filterbasket from injector & clamped hose to front of injector, & reverse flushed them & refited new filter baskets. Injectors were then re used.
     
  5. soda

    Active Member

    Dec 7, 2008
    174
    13
    Is the darlington (MJH10012) the only one i can use,thought, i'm not sure if that one is available to me. Can i use any one similar with the same zeners. The series diode from supply to the 555, is it a 3amp or 1amp silicone diode. The "ecore" you mention, please show a pic of it or explain what it is...thought you get ecore in software too.

    I'm very interested in the insulation tester part, so please show me on the diagram where exactly to add this extra lead.
     
    Last edited: Jan 21, 2011
  6. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Cool stuff.

    I think the gap on that spark plug is slightly out of spec though. :D
     
  7. debe

    Thread Starter Well-Known Member

    Sep 21, 2010
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    184
    Hi soda. More pics, The insulation tester the green wire goes to the coil earth, also the coil metal frame must be earthed to the battery, that is the black lead to the metal frame. An E core is part of a transformer core as in pic. The one i used had a low voltage winding of 2 ohm & .02mm wire. The E core was 40mm long & 15mm thick & one end is ground on a angle to roughly match th CDI unit. The diode is 1A 400V just for rev polarity protection for the Ic. I dont know of an alternative transistor but some one else on the forum may be able to advise of an alternative.
     
  8. soda

    Active Member

    Dec 7, 2008
    174
    13
    debe, thanks alot for all the pic's and help. I'm going to build this tester for a friend of mine who's a diesel-mac.
     
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