Perplexing 1.8 idle and smoke issues

[KenR]

Old plug,same across the remaining three,although the plug in the 2nd cylinder from the N/S was more oily than sooty if that makes sense.

[suzublu]

That gap's huuuuge .75mm to .80mm

[KenR]

It is. New ones are fine though.

[kelvo]

Originally Posted by KenR

Old plug,same across the remaining three,although the plug in the 2nd cylinder from the N/S was more oily than sooty if that makes sense.

I would go with a fuel issue judging by how sooty they are, it's running far too rich so this could be a sensor related issue, the oily one might be unrelated - so times you do find plugs are uneven.

If the engines not had chance to get up to working temperature then they will have fouled up.

I know you can check the coolant temp via the dashboard diagnostics - whether this is the same signal that feed the fuel injection I'm not sure (sure someone will know). It may be thinking that the temperature is far colder than it is and giving a far richer mixture than the engine can run with, it's also not then adjusting the mixture as it warms up.

I would probably suggest getting a good mobile mechanic to look at it - they may well be able to test the various sensors and injectors, or plug into the diagnostics - that may show up straight away the cause, rather than just random component changes.

when my dad had a similar problem on his Volvo 740 it turned out to be the MAF sensor had failed.

[dave lincs]

There must be a local member who could have a look at this poor old car and get it sorted? if I was local I would soon be there looking at it

[KenR]

I think a K series savvy person would be a NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- god send tbh.

[KenR]

I hope no-one gets me wrong, I love the car and when it was running and driving, it was great. I have a door actuator to put on it and also new discs and pads for the front. Not something I would do for a car that I dislike.

If it was a straightforward fix then no worries, however, I can handle stuff on old cars without too much stress, and to a degree with more modern stuff but there is a fine line between throwing money at something that sadly has a relatively low value anyway in the hope that what I do might resolve the issue and putting money into something that will actually sort the issue out.

Okay, so the plugs needed replacing anyway, so done. The cam cover gasket was clearly tired and needed replacing, so done. The jobs so far have been lovely and simple. Inlet manifold, maybe it is that, maybe not. It will get done and I will see what happens. Beyond that my skill level quickly goes to pot.

Anything beyond this and I simply do not have a clue, the ability or money to bring about a fix. I have to make a balanced decision.

I would be happy to sell it to someone on here and If that someone with the time and ability to fix it easily and cheaply does so,then so much the better and good on them. If not, the bridge beckons at £160 for me and yes it would be sad that another one will have bitten the dust but if that is the only route left then that is what will happen.

Anyway, lets see what happens after the inlet manifold gasket fix.

[kaiser]

Get the car assessed by somebody competent and take it from there.

[murphyv310]

Hi Ken.
The 1.8 K series in the 75 and other Rovers only have two coil packs. It uses a "Wasted Spark" system, in other words one end of the coil goes to one plug and the other end to another, what happens is one plug fires just before TDC on the compression stroke and the other in the exhaust stroke on the opposite cylinder and vice versa same with the other coil.
The problem here is if you pull a plug lead off then you'll be disabling two cylinders and it then gets confusing.
One plug is very sooty, that leads me to think that the cylinder it lives in is getting over-fuelled, this could be a stuck injector or an electronic issue, perhaps a T4 session should be tried, the over fuelling could be washing the oil film in the bore and making a mixture of black and blue smoke, this could also be lying in the cat and exhaust, not good for a cat TBH.
Are you getting the engine management light on? If so you could read the codes with Torq and an ELM327 bluetooth dongle, this may help your diagnoses. It may be possible to unplug the injector on the sooty cylinder and see if it makes a difference at all, if nothing changes then it "could" well be a stuck injector.
Good Luck

[KenR]

Hi Trevor, the EML hasn't illuminated at all. I have nothing to actually plug in and read any issues which is a bit frustrating. The fuelling issue idea does have merit. All the plugs are very, very sooty but one is slightly oily as well.