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miss firing on one bank?? help

vt1538

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If the CAS has a wiring problem the engine will not start as it will not trigger either the fuel or spark. Since the same signal that triggers the left bank also triggers the right a fault in this would show up on both sides of the engine also.
I would put the miss down to a seperate issue like a stuck or leaking injector or something along those lines.
 

potshots007

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i dotn know now, ive givin up,
 

adam69

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Hi,dont know if this helps coz i have a V8 but i had a miss, put new plugs,checked leads checked comp,all OK.turned out i have a stuffed cam that was giving number 5 piston some trouble.
 

Immortality

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it could be the CAS as it's actually2 sensors in one, make sure its set correctly, rotate the engine by hand and see if any of the fingers on the back of the balancer are bent etc as this can cause problems. mine was touching the fingers on the balancer and it wore it out. at first it seemed to run a little rough, one day the missus was driving it and it was sputtering/backfiring everytime she touched the gas pedal, drove it homethough at about idle which was bad as well:bang: , luckly she was only one street from home ( she doesn't like walking). changed the sensor etc and all was fine. might pay just to change the balancer also, most engine reconditioners say that everyone they have seen seemed buggered in some fashion or another. other than that i still think it's a wiring/ bad connection issue, if it was a stuck injector or bad cam it would most likely only be missing on that cylinder, not the whole bank but take the tappet cover of the bank thats missing run the engine and see if everythings moving nicely there. you can also just put a dail gauge on the end of each rocker and turn the motor over by hand and compare all the intake valves and all the exhaust valves lifts etc. can you get hold of the gregories manual you will need it to check the outputs on the ecu etc to trace the wiring, can be done without a wiring diagram but will take 10x longer:cry:
 

vt1538

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At no stage has it been shown that the whole bank is actually missing. While he is getting a intermittent spark showing on his timing light it is more than likely caused by this bank having reverse current flow not an electrical issue.
With the reverse side needing greater current to fire the plug a faulty coil is usually the reason for a miss to occur on this side. These have already been replaced & tested on another vehicle.
I would be removing one injector plug at a time & try & isolate the miss to a single cylinder & go from there.
 

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ok, i agree with you on that but on the S1 engine with the triple coil pack each side of the coil pack goes to the oposite bank, so if it was a faulty coil would it not show on 2 cylinders on oposite banks fired by the same coil where as he states that the cylinder 2,4,6 fire ok where as 1,3,5 seem to be missing intermittently. i'll test my engine on sunday with an inductive timing light and see what results i get on my engine (i'll be at my regular job for the next 3 days). you have me on the "reverse current flow", the current flows in the same direction from the coil down the lead to the plug right, wheres the reverse current flow. each coil fires 2 cylinders at the same time, one "dead" cylinder which is on the exhaust stroke and the other which is on the regular spark cycle, the "charged" cylinder gets most of the current from the coil as the charged cylinder is much more difficult to "ignite" and is seen as a greater resistance by the plug and following ohms law draws most of the current.

ok, idea, get 2 inductive timing lights and have one on each side of the output coil and see if they both fire together. just one other thing, a blocked exhaust, maybe, before they join together so only effecting one bank. drop the y pipe at the first joint from the exhaust manifold on the bad side and see what happens, easy test, just use some earmuffs
 
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vt1538

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The "missing" cylinders are all only on one side of a coil pack, the non missing are the other. The cylinder numbering starts on the passenger side with 1,3,5 and on the drivers side 2,4,6.
As far as I can see only a weak coil, bad leads or a faulty spark plug can cause this and usually on one cylinder as all 3 failing is rare.
I am pretty sure that the intermittent spark is just a misdiagnosis as the wasted spark ignition is not commonly understood.
Sorry if I sound argumentative. But I am sure the fault is elsewhere.
 

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ok, well checked all injector wiring, and got injectors ultrasonically cleaned, also have replaced cas, and also used a mates balancer (which works fine on his car) and still no different, but yeah i still unsure yet, will keep looking but not bothered much anymore, everyone has giving some awesome help and i much appreciate it
 

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well im going to buy new leads and plugs and see if it makes any difference
thanks again, going to keep trying, anyone comes up with any new ideas let me know :)
 

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This car is possessed.
 
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