Today I decided to check and clean all the fuel and air intake parts.
Everything I could remove was removed to make it easier to clean.
Air intake, TB, inlet manifold, coils, plugs, injectors were all removed.

It was down to the point where I could see down to the valves.

While at that point I gave the top of the engine a quick blast with compressed air to blow away dead insects, bits of leaves, and general crap that had gathered there. Unfortunately I forgot I had the valve chambers exposed and I think some stuff might have got in them. There wasn't a lot of stuff blow away to start with, but I blew gently into them to drive out anything that might have got in.

I went for a drive, which wasn't too bad, came back and lifted the car level to do some work underneath. When I started it, it just cranked and didn't really ignite any fuel, then it eventually started after a while. There was a lot of blue smoke which had a really rich smell, and idle was incredibly lumpy. Raising the revs seemed to help run a little bit smoother but there was still a bit of blue smoke. Letting off the pedal to return to idle nearly stalled it.

I suspect fuel is not being burnt completely - hence the difficulty starting, rich blue smoke, lumpy idle, and nearly stalling when dropping to idle.

It didn't have this problem before.

All I can think of it I have somehow damaged some injectors when replacing them (really can't see how) or the valve seals are damaged, which I think is most likely.

My questions are:

How easy is it to actually damage valve seals? Would damaged seals manifest in the symptoms I describe? Can I check them by removing bits to the same point as above (ie so I can see into the chambers)? What about replacing them? Can valve chambers suffer from bore wash like cylinder chambers if too much fuel gets in there?

Would faulty injectors inject too much or not enough?

Any other thoughts?

And yes, it was my stupid mistake doing what I did and you're all welcome to berate me for it, but please try to help me too!

 

wow, that's a bit of a sickener....any warning lights or codes?

blue shop roll to bung them first...a hoover to remove dirt, all these things are standard practice, oh, and replacing any and all gaskets once their seals are broken. Forget re-using old gaskets, they're finished once removed.

It sounds like a case of not knowing what you are doing there mate.

 

No warning lights or codes.

Are the intake seals really knackered once removed? They are all in good condition with no splits, not hardened and have plenty contact with the mating surface. I would have thought that if contact is being made all round that's good enough for a seal.

I wondered whether by cleaning the TB (that didn't have a lot of dirt anyway) that the system still thinks it's running with that dirt, and giving too much fuel.

After leaving it last night I removed the intake this morning and looked past the TB butterfly valve; there was a tiny bit of fuel sitting at the bottom, only a few drips, but it did also smell quite rich in there.

 

Carefully check all the plastic and rubber air hoses for cracks, including the part load breather, and did you clean the port? Those parts get brittle and allow air into the system in the wrong places. Also make sure all the electrical plugs are clean and seated properly.

 

Ditto what's already been said, plus have you rechecked the coil packs are in and tightened correctly, the connectors to them in and snapped/clicked fully home? Also as a last resort a hard battery reset to take everything back to standard/original settings worth a try? only takes minutes/half hour tops to do. I would have thought that any dust/soil etc that went down the throat would have been sucked/purged through cylinders.....unless we are talking lumps of wood, buckets of grit and sand etc. things that could cause blockages......I'd do the electrical checks, connector security - pull them appart, visually looking for corrossion and re-secure them , check all spark plugs are tight, air leaks and a hard reset and retest before worrying unduly.... Half to one hour you should have completed and know where you stand. Hope this helps, Allan

 

Vac lines are ok, as is the part load breather.

All the connections checked out ok just now, and I removed everything again to have a look inside. The intake, injectors, and valve chambers look ok.
I saw loads of fuel in some of the chambers that were closed, and some on the pistons of other cylinders.

So it seems I have bad bore wash. I'm obviously getting bad or no sparks in some cylinders otherwise the fuel wouldn't be there. I also have fuel in the oil, which is no surprise considering how much fuel I saw. Needless to say that's being drained right now.

In a bit I'm going to test the plugs with fuel relays disconnected and if they come back fine I'll have to trace the wiring back.
Would a faulty ignition control module (or both) cause this problem?

 

The hard reset, did you carry this out after cleaning throttle/maf? The ecu could be over fueling from old maps - did you carry out the clean to see if it would improve economy?

The amount of unburnt fuel would be a concern, I've had engines with repeated cold starts gather petrol in with oil so once running an oil change is good.

 

Yes, the hard reset was after my cleaning and subsequent problems, and it didn't cure the problem.
Talking to my colleagues this morning, I noticed fuel in cylinders/chambers on both bank, but only certain cylinders, not all of them. I have yet to check further but I still suspect a faulty ICM, because don't they do two cylinders per bank (each)?

 

I'm getting somewhere now...

After work I reassembled but lifted the intake manifold clear of the engine and placed some absorbent material beneath it. I turned the key to pos 2 but not as far as ignition. The fuel rails pressurised for a couple of seconds as usual but the injectors squirted fuel out. I am in no doubt they are leaking. All this was while I disconnected the connector plugs, so there's no way an accidental ground could have caused it.

So I think I have found the problem, and it's happening on most, if not all, injectors. I daresay when the engine is turning the injectors are leaking most of the time, hence the poor performance and permanent blue smoke, also fuel in the oil.

The question now is, do I remove the injectors in case the o rings didn't seat well when I replaced them, or should I just get a set of eight new/recon injectors and save myself the trouble?
I remember what Sean B said at the top of the post about replacing gaskets but might this also apply to injector o rings? It was quite tight getting them back in - maybe I didn't lube them enough.

I suppose I can't lose anything by removing and having a better go at reinserting them.

 

Well, I removed the injectors and have without doubt confirmed the diagnosis.

I had somehow caused damage to the smaller o rings when I inserted the injectors. As a result the poor seal was allowing fuel to bypass the injector. I'm going to get a set of new o rings before I decide I need replacement injectors.

So it turns out it was entirely my mistake and I should have taken more care. I certainly didn't rush the job and I didn't notice anything when the injectors went back in.

 

Happens to the best of us. Let us know when you finish and confirm it is running!

 

It's the only way some of us learn by effing up!

Sounds like the issue is heading for a *fixed* thread - if you have a diesel/hydraulic specialist near you they may be able to perform an injector clean - worth the effort *if* they know what they're doing. Or use BG44 injector flush, it's the only one Jaguar use.

 

Yeah I know but I should have made sure they were lubed. After all, I did just that when I rebuilt my gearbox and I still have the tub of vaseline in the garage...

Anway thanks for the flush recommendation - I'll have a look at that.

The parts won't arrive until Wednesday so now it's just a waiting game.

While I'm in there I thought I might do the thermostat and housing, which is still the old plastic type. It's not broken, but access is a bit easier with the manifold off.

 

Today I replaced the injector o rings, thermostat and housing, belt, tensioner, idler, water pump.

Due to what was in the engine still there was a huge amount of (not blue!) smoke but it burnt off quickly. I let it warm up and took it for a short drive.

So far so good.

The injector o rings are the most tight I have ever had to replace. If I had not damaged them the first time I would not have replaced everything I did, so in a funny way I am happy I did because the pulleys had lost all their grease and there was a crack in one groove on the belt.

 

That was an expensive lesson, but good to hear the outcome. As far as blue smoke, that is usually oil, excess fuel is often black due to the carbon not being burned.

 

So happy for you that you solved the problem. Allan

 

Fingers crossed that you have worked through it.

But don't feel bad, we have all cocked up at one time or another, some of us rather more often.

 

Tell me about it! I replaced a brake caliper on my wife's minivan. On the test drive after the caliper replacement, I noticed the brakes were locked up worse than before. So I ordered a new brake hose, thinking that was the culprit. It took three days to arrive, during which time my wife's van was undriveable. It took an hour to replace the hose, after which I noticed the back of the brand new rotor was ground up really bad. I took the rotor off and discovered that I had put the new inboard pad in backwards during the caliper replacement.

 

I wish I could say I had never done that (on a Jaguar).

 

I think this could get real ugly ...