oli
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Post by oli on Apr 11, 2019 23:20:37 GMT 1
Bit of an update - waiting for injectors to arrive, so I got a chance to have a peek!
It seems much worse, though perhaps this might help identify the problem (assuming something hasn't been upset with the recent work and we now have two issues!)
Constant MIL and slightly rough idle - seemed to be missing a cylinder initially constantly then every few seconds after a minute or so of running. Clearly a poorly motor!
Codes - P0301 (cylinder 1 misfire detected) And - P1313 (misfire catalyst damage bank A)
Also pending codes p1642 and p1000 (which I think are fairly standard ones, just suggesting something is wrong)
Live date showing some rather odd stuff - bank 2 seems to be running beautifully - with short fuel trim 0 and lambda showing smooth curves over a small value close to 1.0 (revving whilst stationary).
The shared stuff TPS as a %, MAF etc all seem reasonable (nice smooth traces with seemingly reasonable values) - I did notice TPS drops down as you release the accelerator suddenly then jumps up to about 50% before smoothing down - I suspect this is a form Of throttle damping.
Bank 1 - irritatingly I'm a little unclear as to which O2/lambda sensor is which - I've got O2B2S2, O2B2S1 and O2B1S2...but no O2B2S1 (just an O2S21 giving crazyvalues of 0.29 to -0.5)
B2S2 was showing 0.71 whilst B1S2 was showing 0.065
This seems to suggest to me that bank 1 is burning very rich or failing to ignite at lot of fuel (poor spark or poor atomisation from injector)
The short term fuel trim for bank one is much higher than bank two - 2.3 vs 0.0 at idle, which I think would fit with the engine trying to compensate.
Does my interpretation seem right?
I certainly think it's an issue with bank one only (which would fit the fault code and the 'sticky' lambda I'd noticed before. I'd be thinking about swapping a few components from bank one and two to work things out by elimination, but I realise that might not be viable for a garage.
Oli
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oli
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Posts: 1,065
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Post by oli on Apr 11, 2019 23:25:00 GMT 1
Sorry, by swapping things from, I mean swapping things BETWEEN banks one and two, almost regarding one as a source of known good parts.
Oli
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Post by valhalla on Apr 12, 2019 19:34:07 GMT 1
Hi Oli, I think you are on the right lines, but it's worth bearing in mind that until the catalyst/s are fully warmed, you may not be getting much activity on the rear oxygen sensors, so you might need to rev the nuts off the car to get some temperature into there.
Two thoughts, whilst I collect some more;
A negative trim on the pre-cat sensor of -2.3 is not a major issue. If it was -7.0 or even -10.0, I'd be starting to worry about injectors jammed open, so maybe the sensor is not so good either?
The rear oxygen sensors should react if you rev the engine for a few seconds, then snap the throttle closed (rich, then lean exhaust) so if you are not getting this, it is just possible that the sensors are not good. On most cars, that would not be an issue, but i have a sneaking feeling that the X-type 3.0petrol is one of those strategies that uses the rear oxygen sensors in the fuel trim strategies, as this is something that Ford USA does quite a bit.
I will try to find a link to a Ford USA series of tests that I (vaguely) remember Eric O. doing on his YouTube channel a wee while back. That explains things very well, and could be a guide to you here.
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oli
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Posts: 1,065
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Post by oli on Apr 13, 2019 22:36:43 GMT 1
Hi Oli, I think you are on the right lines, but it's worth bearing in mind that until the catalyst/s are fully warmed, you may not be getting much activity on the rear oxygen sensors, so you might need to rev the nuts off the car to get some temperature into there. Two thoughts, whilst I collect some more; A negative trim on the pre-cat sensor of -2.3 is not a major issue. If it was -7.0 or even -10.0, I'd be starting to worry about injectors jammed open, so maybe the sensor is not so good either? The rear oxygen sensors should react if you rev the engine for a few seconds, then snap the throttle closed (rich, then lean exhaust) so if you are not getting this, it is just possible that the sensors are not good. On most cars, that would not be an issue, but i have a sneaking feeling that the X-type 3.0petrol is one of those strategies that uses the rear oxygen sensors in the fuel trim strategies, as this is something that Ford USA does quite a bit. I will try to find a link to a Ford USA series of tests that I (vaguely) remember Eric O. doing on his YouTube channel a wee while back. That explains things very well, and could be a guide to you here.
Thanks for the further advice. I'm getting really hooked on the diagnostics. I've been watching a lot of the scanner danner stuff and ordered a couple of books (not his...for the time being...) I'm a bit confused by the oxygen sensor readings. Why would three of the four give me readings in voltage but one in current (ma)? I read something about "wide band" sensors, but I can't see why bank one and two would use something different...or am I missing something really obvious (like the settings on my scanner?!) Oli
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Post by valhalla on Apr 14, 2019 1:44:40 GMT 1
Hi Oli, I'm not sure either (why your scanner has the fourth channel as mA). I would have to look into that on my scantool - they might all have the same erroneous unit-of-measure !
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oli
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Post by oli on May 4, 2019 22:45:32 GMT 1
UPDATE: fixed!
Well I had a day to play with the x- type after my father-in-law called it a day with the garage when they suggested a huge bill for new injectors after already charging for new coil packs and the bill reaching £800 for work done. It was looking very bleak, so I thought it couldn't do any harm to have a tinker!
I'm pleased to say all seems to be fixed and it was a bit bizarre but I've learnt some useful lessons.
After checking for vacuum leaks, i isolated the fault to cylinder one (no change to running when disconnecting the coil) then checked the earth and twelve volt feed to the coil (new as installed by the garage) oddly enough, when i took the manifold off, I found all the spark plugs looked old and cylinder one plug looked very fouled. I also found two rather odd additional plastic gaskets that had been installed between the metal intake and the lower plastic intake (both of which already have a rubber/silicone seal on them) They seem to be jag parts but added by the garage. I couldn't quite see what they were adding, other than a potential manifold leak - so I removed them as well as changing the plugs.
I did also swap the injector whilst I was at it, but I'm fairly sure the original was fine and it was just down to a dodgy plug!
So, never assume the obvious has been checked by others! Start with the basics and work methodically rather than changing parts.
Thanks for the help everyone!
Oli
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Post by valhalla on May 5, 2019 0:09:24 GMT 1
Was it the injector or the coil that you changed in the end? I'm not sure I quite followed your drift there, it sounds as if the coil had a dodgy connection to the 12v and ECU/earth feeds?
A dodgy plug will stress an ignition system to the point it breaks down under mechanical load, like an over-lean mixture or an air leak. Quite often on petrols, the "economy" of not changing sparking plugs and keeping them in tip-top condition at services will come back to bite, with a failed ignition secondary component somewhere or another. Hence you can guarantee that if the plugs have all been left in a distressed state, sooner or later all the coil packs will fail. Not a cheap outcome to a basic service shortfall. Especially if the new coil pack is aftermarket, and subsequently fails prematurely......better to have looked after the OEM's in the first place!!
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Post by sorted on May 5, 2019 8:13:18 GMT 1
So if I’m reading this right, he’s spent £800 at a garage and you’ve fixed it by replacing a fouled plug?
If that’s right, I can’t help going back to the thread the other day where someone asked “why do the public always think garages will rip them off”, here’s a prime example of why!
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oli
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Posts: 1,065
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Post by oli on May 5, 2019 8:35:08 GMT 1
Sorry, that probably wasn't as clear as it could have been.
The wiring all seemed fine.
It's difficult to know in retrospect exactly what the original culprit was - by the time I saw it I'm fairly certain it was the spark plug itself causing the problem.
It could well be the original coil had also failed (already replaced by the garage) either first and thus allowing the plug to get so blackened or secondary as a result of the plug itself failing.
You're absolutely right about failing to replace plugs being a recipe for repairs later.
I don't want to be critical of others (especially as I didn't want the job in the first place!) but it does seem odd to replace all six coils but not even check the plugs. I'm still scratching my head over the gasket inserts.
I've learnt lots about diagnostics (after being tripped up by open and closed loop running!) and the advice not to buy more kit but look at the basic data was spot on!
Oli
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oli
Apprentice
Posts: 1,065
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Post by oli on May 5, 2019 8:44:18 GMT 1
So if I’m reading this right, he’s spent £800 at a garage and you’ve fixed it by replacing a fouled plug? If that’s right, I can’t help going back to the thread the other day where someone asked “why do the public always think garages will rip them off”, here’s a prime example of why! I was trying not to suggest that directly, but it does appear that way. FIL seems fairly sure he was charged for new plugs as well. (Currently looking for the paperwork) I suppose it could be confusion between two technicians working on the same vehicle about what had and hadn't been done...or i might be being naive. Oli
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