4. ENGINE WON'T START

ENGINE WON'T START

  • B

    Hi,
    Unfortunately Loris's kind offer didn't work as his ECU is different.
    I'm back to square one!!
    Some thoughts:-

    1. Coil. I need to check again but I think I saw 1 fat spark followed by weaker sparks when my son was cranking the engine. I will get a friend to crank for me shortly and re-check.
      I've not removed the disty previously;only the cap.
      I believe if I carefully mark the disty body to its mounting then remove the disty body I can then remove the coil? With much older cars it's easy to check the coil by dabbing 12v across the primary, connecting the secondary to a plug and checking for a spark.
      Can you do this with the MX-3 coil???
    2. Crank position sensor. I checked the your resistance value and it reads the right value but I think it's a Hall effect sensor and I wonder if the resistance can still read ok if it fails?? Any ideas??
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  • B

    ECU different in what way?
    Both mine K862B, 3 yellow plugs. 1.8 V6 1996-1997

    Yes by all means mark it before removal.

    If you forget and remove it , its NO BIGGY as all youll need to do on refit is get somewhere near and then do LEARN procedure by jumping TEN and GND in diagnostic socket. (IF WHEN YOU GET IT STARTED OF COURSE)

    CLEAR YOUR BENCH, sheet of white paper for your removed dizzy GUTS and a camera????? Take pics for re assembly help!

    1. undo 2 x 12mm bolts holding dizzy body to cam box.
    2. Remove cap 3 x 7mm cross heads.
    3. Place cam drive (not mounting flange or round body with O ring) in vice withsoft jaws.
    4. undo 3 x cross head screws and top cover with seals etc

    5. Youll now see hall trigger pick ups and vane discs, with a marker, put a spot on the little hole you see on the top disc with the brass triangle rotor post. VERY IMPORTANT FOR RE-ASSEMBLY!!.

    6. With a GOOD crosshead screwdriver undo the central screw in the brass triangle (mentioned above), ITS TIGHT! when removed youll notice the underside of the triangle has a flat that matches the spindle youve just exposed. Remove the two trigger vanes noting the little pimple on the lower one that MUST locate in the hole on the top one on re-assembly,(it should have black marker on it now?)

    7. Remove from the spindle next, either a tophat spacer, or sometimes just a washer?

    8. Now with gentle lifting,remove the hall trigger unit, it is held now only by a male and female spade conection? INSPECT this for corrosion etc?

    9. The coil in its entirety is now visible for your pleasure :lol:

    The CRANK ANGLE sensor I believe is a magnetic inductive pickup device. and sends 'resistance' change info to ECU? whereas the CRANK SPEED/CYLINDER No 1 position sensor in the HALL trigger unit youve just removed is a hall effect signal, producing a small 'voltage' change as a signal at ECU?
    It is very difficult to test these without special equipment like ultra sensitive meters or oscillascopes?etc

    HAVE YOU TRIED BUMP STARTING THE CAR?? (see my prev post on this topic dated 24th APRIL! ) OR WITH TEN and GND jumped!!

    Re read some of replies to refresh possible checks you may have overlooked??? :oops:

    Hope this helps??? :P

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  • L

    @c6b101a394=blackmexyv6:

    ECU different in what way?
    Both mine K862B, 3 yellow plugs. 1.8 V6 1996-1997

    Wait, it's an OBD 1 car? for some reason I recall reading it was OBD2!

    In that case, ECU would work and it's in the post on Monday.

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  • B

    Hi,
    STOP !!!!!!
    I've been working on the car today and checked for spark (no problems big fat spark since I fitted a new carbon brush in the disty cap)
    AND I checked cylinder compression.
    Measurements:-
    80 / 130 / 75 / 90 / 90 / 90 ….......... these are lower than I measured about 1 week ago......

    I'm confident the measurements are ok as I checked pressures on my Yaris and all 4 read 180psi.

    I guess it will not fire below 140 / 150psi so this is my problem.

    BUT I don't understand why.

    I took the car off the road end January after doing a pre-MOT check. The headlights were cross-eyed and the reflectors had come adrift.
    I refitted these and then decided to start the car so as not to run the battery down while aligning the headlamps.

    The car wouldn't start and hasn't started since.

    The oil level is fine and it looks ok (what I can see on the dipstick)

    I guess I could do a leak down test to check if it's rings or valves or look around for another engine. Any ideas??

    Many thanks for your kind offer to send the ECU but I'm now sure mine is ok.

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  • L

    @eececd4588=barrygadd2003:

    Many thanks for your kind offer to send the ECU but I'm now sure mine is ok.

    No worries Barry, let me know if you do need it in the future.

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  • B

    After the initial compression check, a tea spoon of oil down each pug hole and a re test of compression, which if produced higher readings would indicate worn bores/rings? No change would generaly indicate upper engine fault, burnt/bent valves/worn guides/weak springs?
    Very strange that it happened so quickly without something major like oil starvation etc????

    How did car run prior to all this 'NO GO!' ?

    Have you checked that nothings 'nesting' in air filter box Rat/mouse? or a rag has not been sucked into inlet causing mass restriction of induction? and hence compression results?

    If there was low oil level/pressure, then that could effect filling or pumping up of hydraulic tappets and no valve movement, but you say level is ok?

    Does cranking readily extinguish oil pressure light on dash? it should! :?

    Also sump maybe full? but pump strainer may be blocked or sump dented/damaged? causing oil pick up restriction?? ( very difficult to check without sump removal!) :(

    Would still think it would attempt to FIRE even with pressures as low as those :shock: although looking at service book, 142psi is the minimum allowable,and 193psi recommended??? The 130psi highest of yours is also confusing as the other 5 are close…ish to each other???

    Baffling!!

    I have another engine, but Ive started to strip top end down to at least valve spring level to determine its health before install into my other project! I cant do a compression test as theres no starter or gearbox?

    I paid £80 including delivery, so there are some out there? cheap as chips?

    Hope it doesnt come to that route tho barry? :(

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  • B

    PS was the coolant/antifreeze strength correct during 'super cold January' while you laid it up after pre MOT check???

    Could the coolant have frozen?? head gaskets?? or worse split/cracked liners? :shock:

    Just trying to figure the sudden FAIL? :(

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  • U

    Next step is definately compression test again and put a small amount of oil in.

    Do it again dry, then add oil, make sure its in nice and tight.

    A leakage test would be after that.

    But it does not make any sense with the start of your problems.

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  • B

    I wondered if the low compression pressure could be due to the cambelt slipping a notch or 2. Today I started the procedure for removing the cambelt cover. What a palaver….. The bolts behind the power steering pump are a real pain to get at. Also had to make a steel strap to bolt to the crankshaft pulley to hold while undoing the big bolt. Still not there yet but not much left to do.
    I'll check if the cam timing is correct and then decide whether to sort the engine or replace with another.
    Out of interest is the Mazda 323F 1.8V6 engine exactly the same???
    Thanks for the replies.They really do help.

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  • V6 in a 323f is a 2.0, but is from the same K family -KFDE/KFZE

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