Odd misfire
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  1. #1
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    Unhappy Odd misfire

    Was driving back up the M1 this evening, and tank was running low. Got cought behind a Clio and lots of spray. then randomly about 20secs later, engine started loosing power on and off, like fuel starvation, so just though would limp to the next junction and fill up. Did so and noticed that no 2cyl was misfiring, so filter came off and 4mile drive home, got home to inspect, engine running rough as s**t. and trumpet 2 black all the way down. can find any faults on the wiring side, and plug is ok, but black. The other odd thing is that the Tacho would read zero when I tried to stonk it. thne I would have to restart the car for it to work again. Im running emerald with my tb's, any ideas?? or is it multi meter time?? Couldn't plug laptop in as didn't have the cable with me. Any idea??

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  3. #2
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    blocked fuel filter/ fouled injector? i say this cos you ran it low on fuel, thereby dredging all the crap from the bottom of the tank and into the system, thats my guess anyway

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    It's only cyl 2, I think I may switch the injetors round and see what happens there. the fuel filter is brand new 900miles ago. I haven't really been able to investigate yet. Was hoping it would just be the water!

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    Originally posted by j1400
    It's only cyl 2, I think I may switch the injetors round and see what happens there. the fuel filter is brand new 900miles ago. I haven't really been able to investigate yet. Was hoping it would just be the water!
    sorry to dissapoint!!! well it may well be water related too!!

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    So it sounds like No.2 is running rich rather than lean. I would do what you suggested, swap the injectors round and try to eliminate them as a cause. What injection are you running, batch or sequential?

    Where is your ECU mounted?

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    ecu is mounted in the car, passengers side footwell. I'm going to swap them around if it's still running poorly when I run it on friday.
    If it's fine then it was water and I'll have to seal the engine loom better. if not then swap them over. but why would only 2 overfuel?? Running Batch surely 3 should aswell??

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    If you're running batch injection, then all 4 will be firing at the same time.

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    ok then it's wired with 2+3, 1+4 so thought it would be firing grouped?? runs just as poorly if I disconnected inj 2. very lumpy

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    You haven't got a dampness in the footwell that might be affecting the ECU?

    Are you running distributor ignition? If so then if the coil / dizzy was wet then maybe this would tie in with the tacho feed from the coil disappearing? (if thats how its set up of course, if not then ignore everything I've just said) .

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    Bone dry. coil pack, direct tacho input from ecu. plus ecu is weather proof appaently

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    Bugger, sorry about that. I'll have another think then. Let me know how you get on with it tomorrow.

    Cheers

    Rob

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    Cheers, can't play till Friday. It's at home and I'm in cardiff. I'm gonna ring Emerald tomorrow abotu it and see what Karl reckons is the problem, cause it's f*kin odd that the ecu is registering no rpm on the tacho :S may be crank pick up is duff, then why would it run?? Arrrggghhhh I hate stuff like this.

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    Right my dad has just run the engine, and it's still being like a pile of poo, he thinks that injector on cyl2 is jammed open and flooding the cylinder. Can this happen, and explain why it's ok high up the revs?? When you drive it at higher revs you occasionally loose power, so fuelling maybe, anyway borrowing a set of injectors to see of that solves the issue. fingers crossed anyway. Otherwise it's a sump off, then compression test I guess.
    I'll keep you all posted
    James

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    er, compression test before you remove sump, tis easier, i reckon you have a lump of crap round the injector pintle, holding it open a little, or giving duff spray pattern, try different injectors if you can borrow, or swap them from cylinder to cylinder to see what happens, hope you gt it sorted

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    injector is filtered
    its crank sensor, must be summat like that, but no idea why it runs!
    or, if you run dizzyless, does the ecu take a rev signal from the 2/3 coil thing (can you tell i dont know what coilpacks do? lmao)

    if ecu is not seeing revs its not changing the fuelling or ignition table from the site 0 positions i reckon

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    Been having words with KArl at Emerald today, he's a bit miffed, but basically it's porbably not headgasket and is a funny electrical fault with the car, so it's time to swap everything from one engine ot the other.

    Or 16vastra ecu generate the pulse to fire the coil pack so it's tacho feed from crank sensor.

    Other problem is the ecu is getting hit by "noise"/interferance and is causeing it to reset, but we'll find out tomorrow I guess

  18. #17
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    all sorted, coil pack was water logged causeing a weak a spark from one of the 2+3 bank not both though, put it in the oven on a low heat for 30mins to dry it, bagged it up in the car and no problems so far.

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    I wasn't too far out then .

    Glad to hear its all sorted then James.



  20. #19
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    Cheers Rob, shame I got nicked when it was being tested!!

    First time I went to 7600 in third the coil died and caused the ecu to shut down, so I'm not too tempted to do it again. It's fine in 1st and 2nd, but third seems to load the coil for too long. but testing will tell, maybe save for a brand new one with guarantee on it.

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