Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 15 March 2010, 23:52:02
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In summary - the 3.2 manual Josh recently bought from simon_omega.
Went to have a look tonight.
Well - it's no surprise the 1-3-5 lambdas are unhappy. It's misfiring like a pig.
Read the codes - it logged a code for misfires on 1, 3 and 5.
Cleared the codes, ran the engine - and the same codes again came back.
Compression tested that bank - and each pot had very healthy compression.
Fitted new plugs, and put a known good coil pack in the 1-3-5 bank from the MV6. No difference at all. Lovely misfire.
I actually think the lambda/enrichment thing is a red herring... caused as a result of the misfire / unburnt fuel / incomplete combustion - what do others think?
My thinking is this.
Because the misfire codes are for the three pots on the RH bank, and on the basis plugs, compression and coil pack are fine -
I am thinking, wiring issue from ECU to coil pack?
Interested in your thoughts :y
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What is the fuel trim doing for the 1,3,5 bank?
Kevin
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What is the fuel trim doing for the 1,3,5 bank?
Kevin
Unfortunately, the bloody ELM would not read the fuel trims :(
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What is the fuel trim doing for the 1,3,5 bank?
Kevin
Unfortunately, the bloody ELM would not read the fuel trims :(
That's odd. Mine does. What software? Scantool.net?
Cam timing OK on that bank?
Does it run OK from stone cold or still misfiring?
Kevin
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What is the fuel trim doing for the 1,3,5 bank?
Kevin
Unfortunately, the bloody ELM would not read the fuel trims :(
That's odd. Mine does. What software? Scantool.net?
Cam timing OK on that bank?
Does it run OK from stone cold or still misfiring?
Kevin
It would read/reset DTCs, and a few other functions - but generally it crashed out with an error, requiring a shut down of the software, and re-connection of the lead....
I have only seen the car in a warm state... are you thinking possibly it's OK while the lambdas are in open-loop?
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Haven't yet looked at cam timing - but I did comment it will need to be checked, at this rate :(
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Just to add - I put a jump lead from the battery negative to the engine lifting eye, and re-started the car.
The misfire then immediately went away, and it ran smooth as silk.
But later, I Was able to get it to miss with the lead still connected.
I did start thinking along the lines of bad engine earth.. but needed a multimeter for more tests..
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It would read/reset DTCs, and a few other functions - but generally it crashed out with an error, requiring a shut down of the software, and re-connection of the lead....
That's odd. I find it quite stable.
I have only seen the car in a warm state... are you thinking possibly it's OK while the lambdas are in open-loop?
Yes. Cold running takes the lambda loop out of the equation, of course.
Did it get any better / worse when you cleared the codes? (this also resets the block learning on this ECU)
Kevin
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I did start thinking along the lines of bad engine earth.. but needed a multimeter for more tests..
Does sound like a possibility. I would do a thorough visual inspection of the engine-to-chassis strap and the ground to the engine management loom (can't remember where it is on this engine). ::)
Kevin
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I think it was moreso my laptop - the OS is unstable and it needs a rebuild. Everything crashes :D
It didn't seem any different after the resets.
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(can't remember where it is on this engine). ::)
Kevin
3 wires bolted on the rear of the 2-4-6 head?
Visual inspection was hard at the time - very dark etc - but this will need to happen. There are lots of traces of wiring being cut (and not insulated) around the battery terminals etc, I am guessing plod kit - it needs a good tidy up really, but nothing drastic.
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at the oxford meet, TB said to check the wiring to/from 1,3,5 to ecu, and i believe it was similar response to a thread Simon posted on same issue... as i recal..?
have also seen other threads where ecu was fubar due to some donkey (at Mr Clutch in slough, in one case) trying to connect the battery up backwards, or so the story went. Similar symptoms.
Not sure if TB suspected lambda at some point as well? or was that on another car, there where alot of facelifts at the oxford meet, oh, and a Rover. ;D
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I saw thise one at Oxford meet, and after a moment of suspecting wiring to 1/3/5 coilpack (or associated earths), went back to thinking lamda related. I never saw the car cold, but going on the symptoms that were described that it was fine until it went closed loop. Also fine at WOT judging by the tyremarks up the road ;)
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Might be worth a try with that Lambda unplugged on that basis that that's likely to force it open-loop, I guess? :-/
Kevin
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I'd agree with that, Kevin :y
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Might be worth a try with that Lambda unplugged on that basis that that's likely to force it open-loop, I guess? :-/
Kevin
... Just for a quick try, mind, as the Lambda will be unheated and prone to contamination. :y
Kevin
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Haven't yet looked at cam timing - but I did comment it will need to be checked, at this rate :(
Timing is perfect.
THEBOY told us at kidlington meet, that we should check the return wires from the coil pack to the ecu.
History of the car is the guy had cooked it, and put new heads on and belts etc...
i took it on UNFINISHED (over heats) due to the oil cooler, trailered it back, and did the oil cooler as it had gunge, the rest is now current history in the making!
strange tho, it runs fine when cold in the morning, its an enrichment issue im sure of it,
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ALSO:
We swapped the ECU and transponder the other week RULING OUT THE ECU.
i would check earths if i was you
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Sounds more like a closed loop issue to me...does not sound coil pack related.
Hence lambda sensor...I wonder if the 2 lambdas on the 1-3-5 bank are connected correctly....
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Haven't yet looked at cam timing - but I did comment it will need to be checked, at this rate :(
Timing is perfect.
Don't take it personally mate - when trying to find a fault on a car that's new to me, I try and treat everything as an unknown :y
My thoughts soon came to a wiring issue - as TB advised you - but with hindsight, I wonder if it's the wiring to the Lambda, as Mark says, that's at fault.
It would be worth buzzing it through... :y
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yeah sure, was saving you time, my mate is head mechanic at vx, he has looked at car in depth, but could only spare so much spare time on the car for me. you boys are usualy manic with your own work to do.
He checked the timing on the belt and adjusted it a minor fraction.
it doesnt come off enrichment properly. thats the main problem, so yeah check the 135 sensors i would.
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yeah sure, was saving you time, my mate is head mechanic at vx, he has looked at car in depth, but could only spare so much spare time on the car for me. you boys are usualy manic with your own work to do.
He checked the timing on the belt and adjusted it a minor fraction.
it doesnt come off enrichment properly. thats the main problem, so yeah check the 135 sensors i would.
I disagree....
The symptoms sudgest that it works fine in open loop mode using the default maps......what its not doing is working in closed loop mode where the lambdas are inputing to the mixture.
Hence why its fine during warmup and WOT as both these work off the default map.... :y
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ok, well what i meant was, its fine first thing, but then doesnt work fine, which you summed up.
good luck with it, that car goes like absolute stink, i recomend you get it going :) :) :)
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wow im not half as technical as some of you guys, but just a thought to add to the mix...i had a hell of a misfire and i swapped the HT leads cos 1-3-5 are the longer HT leads and they run down the back of the engine where it is hottest! have you checked the leads? or did you go straight for the coilpack? as it turned out i needed a coilpack too but i could easily see how the leads might be affected given their position down the back there near the exhaust
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wow im not half as technical as some of you guys, but just a thought to add to the mix...i had a hell of a misfire and i swapped the HT leads cos 1-3-5 are the longer HT leads and they run down the back of the engine where it is hottest! have you checked the leads? or did you go straight for the coilpack? as it turned out i needed a coilpack too but i could easily see how the leads might be affected given their position down the back there near the exhaust
Coil pack sits directly on top of the spark plugs on the 2.6/3.2 V6s so there are no leads as there are on the earlier V6s. :y
Kevin