Cylinder miss?

[trevor]

Hey guys,
Last week car started idling and missing revs at low speeds (0-30km or so). Fuel pump was also whining and couldn't get through thing to turn over. Eventually it did but runs very rough at idle and low speeds.

Diagnosed it as the fuel pump, even though I replaced it about 5 years ago with a genuine one. Fitted the new one today and much of the same, maybe slightly better.

I remembered driving a commodore that had a faulty spark plug that felt similar to my disco regarding missing. The nanocom is showing some bad cylinder readings at idle. See pic attached.

Fuel pump still making a whining noise in II position, car starts okay but still rough.

Idle speed error from nanocom showing -20 to +20 at idle if that's relevant.

I've attached other pics as I'm not sure what's normal. I'm sure that something is wrong with cylinder 2; but any advice on anything would be much appreciated. https://www.aulro.com/afvb/images/imported/2016/08/693.jpghttps://www.aulro.com/afvb/images/imported/2016/08/694.jpghttps://www.aulro.com/afvb/images/imported/2016/08/695.jpg

Any help from you guys would be much appreciated.

Trevor.

[trevor]

https://www.aulro.com/afvb/images/imported/2016/08/690.jpghttps://www.aulro.com/afvb/images/imported/2016/08/691.jpghttps://www.aulro.com/afvb/images/imported/2016/08/692.jpg

These faults too in the engine fault menu.

[sierrafery]

Hi, for the cylinder roughness first of all check the ECU's red plug and if there's oil you need a new injector loom ASAP, if no oil there check at the upper plug too(the one at the front of rocker cover) cos if there's oil it means that the loom is already gone just that the oil didnt reach the ECU yet, the main problem is not the oil ingress at the ECU but the weakened contacts at the injector solenoids... if i was you i'd replace the injector washers and seals too if the rocker cover is off anyway cos the pump's noise can be due to slight leak at the copper washers as compression gets into the fuel rail, this thing can create rough running as well, also bad quality fuel filter can make the pump noisy.... If you erase the codes do they come back all?... the ambient pressure looks good on the live reading

[geordiepride]

do a click test or shut down one injector at a time

shutting down one injector at a time you will be listening for any changes

those balance readings don't look right i may be wrong as i don't own a Td5 scan gauge

but those numbers. to me you have injectors compensating

before replacing any thing whats the fuel pressure ? filter changed also the screen inside the head is the fuel pump screaming ?

[trevor]

Thanks guys.
I will have a look at the red ecu plug tomorrow.
For the upper plug did you say I have to take the rocker cover off?
What's the process of replacing the loom?

Regarding the injector washers and seals what would be the difficulty level?

Replaced the fuel filter when I started having issues. Got a
genuine one with my genuine fuel pump and it's still making a whining noise. Could it be a blockage?

I'll erase the codes tomorrow and check.

What's a click test or how do I shut down individual injectors geordie?

I'll have to check fuel pressure tomorrow too.

Thanks again

[sierrafery]

I have the feeling that you'll have oil in the ECU plug then no need to check the upper one though the only thing to do is to squeeze it's sides and unplug it without any other complication, to get an ideea about the work see this: http://www.discovery2.co.uk/Injector%20Seals.html you can see in the first steps how to remove the loom too also that injector removal tool is not compulsory you can lever up the injectors with a curved allen key

[geordiepride]

[QUOTE=trevor;2573258]Thanks guys.
I will have a look at the red ecu plug tomorrow.
For the upper plug did you say I have to take the rocker cover off?
What's the process of replacing the loom?

Regarding the injector washers and seals what would be the difficulty level?

Replaced the fuel filter when I started having issues. Got a
genuine one with my genuine fuel pump and it's still making a whining noise. Could it be a blockage?


my fuel pump has screamed at me twice ..the first time was a blockage ..the second time it was combustion washers

first is to clean the full fuel system start from the tank pick up and work way forward filter and filter housing valves

then the pressure regulator there is a screen filter inside the head but before doing this make sure you have a fresh fuel regulator gasket

to be honest if it is your combustion washers the issue making the pump scream ... it not a bad thing to clean the full fuel system as carbon is entering the fuel ..while doing mine I found the gauze screen inside the head full of carbon deposits nearly to a stage to being blocked

[discorevy]

If your old pump had carbon on it / was blackened then it will more than likely be your injector washers as has been mentioned above, not a big job but make sure the washer seats on the injector and head are spotless, when replacing them , also keep the injectors in order , especially if you don't have nanocom or similar

[LRD@HSV]

after 4x4ing it started running rough i got home and called a mate with a nanocom the fault was open circuit on inj 2 >
New loom cleared fault no prob since <

[trevor]

Thanks for the input guys.
Looks like I've got a list of things to check for this. My pump was about 3-4 years old and looked brand new. Had the tank cleaned a few years ago too. Will start from simplest to most complicated in the search for answers. Will update when I get it fixed.

Trevor.

[trevor]

Ok. Plenty of oil in the ECU. Letting it drain for a couple of days to see it that helps. Started it up tonight and had trouble starting as it has been recently. Have to put foot on accelerator to turn it over. Drive pretty well actually. Don't think the roughness was there, even though I was looking for it.

Cylinder pressure readings from nanocom not as extreme also. But it's cylinder 3 that's reading as out not 2. All around -2/3 but cylinder 3 at 7-8.

Will update when the ecu has drained of oil

[sierrafery]

You'll have to replace the injector loom ASAP cos even if the oil is out from the ECU as you plug it back it will keep coming and the main issue is that the contacts on the solenoids are weak at this stage and that's the main cause of the missfire... but as you are already there it would be a good move to replace the washers and seals too then you are covered in this area for few years... only use GENUINE parts there

also after the work is done you'll have to clean the ECU plug once a week untill all the oil leaves the harness

[discorevy]

Also worth removing the seal between connector and ecu so residual oil will drain out rather than into the ecu , just put it back if your going to go through water crossings:)

[trevor]

So let the ecu drain free of oil for a few days and car started up really nicely. Ran as good or better than I remember. Decided to get Hunter cuthill in geelong to do it as I already misdiagnosed it as a fuel pump which cost me $540. As I noticed, they didn't pick up a miss on their diagnostics either but still replaced the injector loom due to the oil in the ECU. Picking it up tomorrow.

[turps]

Injector looms a quick and easy to change. Especially if you hav a 1/4 socket set.
I brought a spare loom that lives in the car.

If you ever change it at home. I would fit a new rocker cover gasket also.

[trevor]

Yeh I have changed the loom a few years ago but didn't seal the rocker cover well enough at that time. I'm at the point now where while it's expensive to get the specialist to do the job, I know it's done right, the right thing is fixed, and I have piece of mind I haven't missed something when I service it