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Misfiring - still - is this a clue

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Old Aug 11, 2002 | 06:34 PM
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Trout, Link owners earth their throttle posi sensors I'd say go for it, but try the obvious places first to save you the hassle just in case that clears your problem. Some Legacy owners earth their exhausts, too - has something to do with the O2/lamda sensor according to some.

Good luck - hope this sorts it.

edot for clarity and a mistake

[Edited by AJbaseBloke - 11/8/2002 6:36:26 PM]
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Old Oct 11, 2002 | 10:28 PM
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OK, Banner add for garage coming soon...

...Bob - didn't you see my email - sent it last week...

...didn't buy gold plated ends...

...created new earth leads to block, manifold and nearside strut tower earthing point...

...cleaned up and vaselined existing earthing points...

...wow, car feels so much better

Any hesitation or misfire is gone.

In terms of the big, no voltage misfire, have not seen it - but it was always sporadic - possible culprit was water scavenger pump relay - realised the wire straight to the battery positive did not have a shielded spade connector on it - and the relay was exposed to damp now that TMIC has gone. Could well have been arcing across, but not drawing enough current to damage wire - but drawing enough voltage to kill everything. It has now been removed.

Car is running so sweetly now - will have to wait and see if big short continues. Thanks for the battery comment - that was one of my last thoughts.

Trout

[Edited by Trout - 11/10/2002 10:31:30 PM]
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Old Nov 6, 2002 | 11:35 PM
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For those of you that have followed my tribulations.

Car has not been 'quite' right for a while and suffers from intermittent misfire at peak torque.

This happened for the first time when it was dark - big misfire - but also potentially a big clue. When it did it - all the lights/dials/etc went dead for a split second - then car was back to normal.

Looks like total electrical failure - albeit momentary. Since then I have had a brief chance to check the basic integrity of the earth leads from the battery - both seem fine.

Also have refitted injectors/spark plugs/etc - all to no avail.

Any clues anyone?

Trout
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Old Nov 6, 2002 | 11:52 PM
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Plain & simple connection from the battery to the cables? Crud (green variety ) in there? Could be giving a low enough voltage that it drops below a threshold (whatever it is!) then everything goes?
I know, a bit basic, but my brain's not working very well at the moment
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Old Nov 7, 2002 | 03:27 AM
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What kind of ECU are u using ?, some let you check the spark of each coil.

Probably you have engine loom damage, you can also check if there is some positive connector that is grounding. I had this on my car, sudden misfires, and when car was left without starting it for a few days, the battery would drain. Problem was a wire which was touching the chassis.

Carlos H.
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Old Nov 7, 2002 | 05:36 AM
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Trout,

I'd give the earthing trick a go - not much to lose, but we've seen some surprising effects by cleaning up the signals.

HTH
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Old Nov 7, 2002 | 02:19 PM
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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gimme a shout if you want a hand to try and sort it..

does it just do it when warm or even from cold?

David
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Old Nov 7, 2002 | 03:47 PM
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Check all the main power connections, clean, refit with some grease, vaselene will do.

Altenator, battery + and -, chassis earth, ignitor block earth, inlet manifold earth (under ignitor block).

At high frequency, small bits of oxide etc will make a capacitor, effectively increasing the resistance as the fequency (revs)increases. Just go through them all logically.

Paul
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Old Nov 7, 2002 | 08:20 PM
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Pavlo,

what you say makes sense....but would that make everything turn off suddenly.

Am doing the multipoint earth thing this weekend...

...a bit of a nightmare if it is a positive short - however would a single positive short make everything else cut off?

Cheers,

Trout
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Old Nov 7, 2002 | 11:40 PM
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That was what my thought was about the voltage level - there may be a voltage level (well, probably is!) that the ECU can't cope below - so all the voltage needs to do is drop momentarily below that level & things go a bit squiffy. Which sort of fits in with Pauls thoughts? I think (he says hopefully...)
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Old Nov 8, 2002 | 12:39 AM
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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positive short would make everything go off.. but would make a mess off the cable, so is more likely to be a dodgy ground...

Remove water bottle and check multiplug under there...
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Old Nov 8, 2002 | 06:13 PM
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Well everything goes off - so don't think it can be ECU voltage level - mmm - should try datalogging it...

...will try multiplug - also thought of positive short, and have made a check of the main wires and none have melted yet - however have two primary suspects - the wires into the water injection pump relay and the wires into the water injection scavenger pump relay. Standard relay with 40amp cable straight to the positive - and pins on a standard relay are very close together!

Also bought 8m of 16mm earth cable to make the car heavier - must cost at least 1bhp so I hope the mod releases more power than that

Another thought - is it worth taking an ground from the battery right to the ECU earth? Seems to make sense given all the earthing mod discussions! (Could also explain why my fueling/lambda sometimes goes inexplicably squiffy!).

Trout

PS Dave - thanks for the thought on the multiplug - will check it out if MY99 cars have them
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Old Nov 8, 2002 | 07:33 PM
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uhmmmmm this has reminded me that on some cars fitted with LINK, the rev/rpm meter goes crazy ..... will grounding the TPS solve this ? (which is the ground wire on the TPS ?)

Carlos H.
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Old Nov 9, 2002 | 06:08 PM
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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Like I say if you need a hand...

Also I've got a mate whos a bricklayer if you need it for your garage..

Ask steven what I said when he told me how much.

David
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Old Nov 9, 2002 | 07:26 PM
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From: Flame grilled Wagon anyone?
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cant repeat that on here.
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Old Nov 10, 2002 | 09:50 AM
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Talking

LOL - well am looking out of window, with earth cabling in hand - think - oh dear it is raining very hard - wish I had garage now!

Trout
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Old Nov 10, 2002 | 11:43 AM
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Trout

What you mean you moved from DarnSarrth with all your millions and aint even got a Garage... I feel soory for you....
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Old Nov 10, 2002 | 12:51 PM
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From: Flame grilled Wagon anyone?
Wink

you can always use my garage if you want
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Old Nov 10, 2002 | 01:23 PM
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what about poking the bonnet into the woodshed?

Paul
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Old Nov 10, 2002 | 04:51 PM
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Tent anyone ?
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Old Nov 10, 2002 | 04:59 PM
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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small violin?
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Old Nov 10, 2002 | 05:02 PM
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Banner add for "Trout's Garage Fund"?
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Old Nov 10, 2002 | 05:47 PM
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long shot mate ,
i was having problems with my evo 6 this time last year driving along and it would turn off every thing would dim , turned out one of the battery cell was shorting out ?
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Old Nov 10, 2002 | 08:15 PM
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From: Flame grilled Wagon anyone?
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Sussed it Trout!!


































It wants a garage
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Old Nov 10, 2002 | 09:06 PM
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Hi Trout: The earth mod is about 5 bhp but Hks do one for about £155 with gold plated ends. Only know one person who bought one so ask Christian what it was worth!!!
Good luck. Let us know what you find.
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Old Nov 10, 2002 | 11:37 PM
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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Could well have been arcing across, but not drawing enough current to damage wire - but drawing enough voltage to kill everything. It has now been removed.
Hmmm, No!
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Old Nov 11, 2002 | 07:28 PM
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Hmmm, no, what oh maestro?

Trout
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Old Nov 11, 2002 | 08:46 PM
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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if its killing the main lights then its taking some current.. and it would do damage.. however if its a faulty ground then it wouldnt necessarily damage the wire..

I think thats how I meant to type it.

David
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Old Nov 12, 2002 | 07:05 PM
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Groovy - still not happened again - so fingers crossed...

...also might replace battery as a precaution - it is four years old!

Trout
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Old Nov 12, 2002 | 08:54 PM
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david, since you are loaded, get yourself a yellow top dry cell optima.

Strangely you do notice the difference, most notably on starting.

You could get yourself over to the appropriate garage and steal the relevant one that belongs to me that was stolen from me by a mutual friend
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