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Old 18th March 2019, 17:23   #1
Canonite
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Default What the heck is this? (Misfire too)

Been having a little bit of a snoop around this Celestial Press car.

It’s misfiring on cylinder 4 according to the Torque pro app and was giving P0304 and also showing P1319. I cleared the codes, the. Swapped the coil pack of cylinder 4 with cylinder 3 on the front bank. I’m not super down with the Torque app, is there anything I should add that would monitor it while running?
It’s still showing a misfire on cylinder 4 but is now also showing P0175 which suggests running rich on bank two. Is this directly resultant from swapping the coil packs over?

This is on the top of the steering wheel cowling, and has two wires. The live goes to the LSM and is earthed just next to the bonnet pull.
Any ideas?


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Old 19th March 2019, 08:57   #2
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That looks like an indicator light wired into the red rear fog lamp circuit.

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Old 19th March 2019, 09:08   #3
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Originally Posted by SD1too View Post
That looks like an indicator light wired into the red rear fog lamp circuit.

Simon
Thanks mate, i'll put the fogs on and see what happens. Why oh why would this be even needed?
Dyou have any ideas what could be causing the misfire?
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Old 20th March 2019, 08:06   #4
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This is probably irrelevant, but might give you some thought?
I have a 2.5 KV6, my 3rd one, all of which I have converted to lpg using a Bigas/King system. I recently swapped it over to the 3rd car, and was confronted by what appeared to be a higher rev misfire, and seemingly relevant to lpg only. I went through a serious of logical checks and swaps of parts, which I don't think I need to elaborate on, until narrowing it right down. One relevant point however, I did find I had to change 3 petrol injectors, due to cracks in their body. Probably caused by me whilst swopping parts?
The simplified analysis at the end, showed an lpg fault, over about 3000 rpm. There was a regular misfire, which unusually did not give an immediate lpg fail, and revert to petrol as it normally would. As it was not present on petrol however, I originally eliminated anything common to both fuels, such as spark plugs and ignition coils; obviously by this time I had discounted petrol-only parts such as petrol injectors.
As well as the misfire, the engine fault light would show only above about 3000 rpm, but going off if I took my foot off the throttle. Keeping it on however always resulted in the light remaining on, and a fault code being stored. Oddly, this always read as a "Cylinder 2 misfire".
My thoughts then turned to something lpg only, and related to cylinder 2.
I replaced all the lpg injectors with new; the old ones had done around 250k miles, and I was forever re-soldering the wires to them as they were well past their sell-by date! There was a slight improvement in performance, but the fault basically remained. Then I had a brainwave....
Gas burns slower & hotter than petrol, so it is best to use iridium plugs. (Already done). But gas apparently shows ignition faults up earlier than on petrol - and I had this fault many years ago which I had since forgotten about. So I next tried the easiest route, changing coils. Of course, cylinder 2 is not the easiest to access! Twice I fitted a spare coil on cylinder 2; each time there was a definite improvement, higher rpm was achievable before the light came on, but this soon reverted to "as before". I cannot explain that though?
3rd time, I swapped coils with one of the front ones. Once again, slight improvement, which quickly deteriorated again. The same fault code was still read - "Cylinder 2 misfire" - whenever the light stayed on, but it did take a bit longer for it to stay on.
The wiring to the (petrol) injectors is modified for an lpg conversion, each injector feed being diverted into the lpg ecu. There are then 2 outputs, going either to the petrol or lpg injector, as required. So I once again checked the wiring was ok (it was).
This left only the lpg ecu, which came from the other car, and was almost new. In short, it is made for use up to 8 cylinders, so has 2 spare ports. I swapped port 2 for one of the spares, and the fault was cleared.
No misfire, high revs available without an engine light, job done (almost....).
Strangely, next day the engine light came on, when starting from cold. The code read was "Bank 2 rich". The engine always starts on petrol, automatically switching to lpg when conditions are met, usually within 1/4 mile. I cannot explain this code happening either, but it is the same as yours? Not happened any more in the fortnight since.
Sorry about the long winded reply, but it might lead to some pointers. Try moving the fault away from the rear cylinder to the front, for easier access. Injectors, coils, plugs all worth trying.

Stewart
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Old 20th March 2019, 09:54   #5
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Quote:
Originally Posted by Canonite View Post
Thanks mate, i'll put the fogs on and see what happens. Why oh why would this be even needed?
To pass an MOT you need a fog light on warning lamp. Comes on in the display on high line cars, and a separate LED lit icon on low lines.

Bet yours isn't working and this is a cheap and cheerful 'Yee Ha' fix.






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Last edited by Mike Noc; 20th March 2019 at 23:09..
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Old 20th March 2019, 12:12   #6
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Quote:
Originally Posted by Mike Noc View Post
To pass an MOT you need a fog light on warning lamp. Comes on in the display on high line cars, and a separate LED lit icon on low lines.

Bet you're isn't working and this is a cheap and cheerful 'Yee Ha' fix.

Nah, the redneck fix would be system of mirrors to show the rear light cluster in the drivers door mirror.....


What you've got there is the lazy 'mechanic' fix.





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Old 20th March 2019, 12:39   #7
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Quote:
Originally Posted by Mike Noc View Post
To pass an MOT you need a fog light on warning lamp. Comes on in the display on high line cars, and a separate LED lit icon on low lines.

Bet you're isn't working and this is a cheap and cheerful 'Yee Ha' fix.
It is exactly this, thank you.
The rear fog doesn’t have illumination anyway on our cars does it?
This car has message centre IPK but the top screen doesn’t work.
Does seem a bit of a daft way to address the issue.
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Old 20th March 2019, 12:51   #8
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Quote:
Originally Posted by Canonite View Post
The rear fog doesn’t have illumination anyway on our cars does it?
Yes it does. Appears on the upper screen of both standard and message centre IPKs.

Rear fog icon on message centre screen.
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Last edited by stevestrat; 20th March 2019 at 12:59..
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Old 20th March 2019, 13:35   #9
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Try swapping the ht leads around, and have you checked the plugs?
It could also be a leaking inlet manifold gasket or worst case, a damaged valve.
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Old 22nd March 2019, 14:52   #10
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My ZR was playing up, missfiring on low revs and under load. Changed plugs and coils, still the same. Decided to change the HT leads, it is now a totally different car, all fixed and smooth again.

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