NITROUS OXIDE ( nos / n2o ) advice forum

Not necessarily a nitrous problem but diesel related.

The Fabia started to suddenly misfire and smoke - grey smoke - when going over to buckingham.

Have checked the valve and injector movement and all seems OK. The garage have the car and on leakdown this is all good so no piston/valve damage.

The injectors look ok but the pd injectors take serious specialists to test and tune them.

Any ideas on specialists or any other ideas at all?

Hi

IF its "white" smoke its usually head gasket or cracked head or block as a general rule...

They can test it using a Snap-On block tester, which is a royal blue coloured liquid that is put into a plastic tube thing that is inserted into your coolant overflow bottle and the gases above the coolant are drawn through with a little rubber puffer...

IF the liquid changes to green or even worse yellow...its head gasket failed or possibly head cracked or even more rarely cracked block....

All the best Brett

White smoke on a diesel is usually "boiled" fuel - ie it hasn't combusted. You should be able to tell if you get a whiff of it.

Combined with poor running, it could be a timing issue which again, is fuel related.

If it happens to a cold engine and clears up when warm, it's usually glow plugs but this sounds like it happened when warmed up so something's gone awry. A slipped cambelt is one cause though I'm not aware of how complex an ECU system it has so would only be second guessing but check the sensors either via a dedicated diagnostic machine (a proper one, with an technician that knows how to use it!) or DIY with a multimeter and a few probes.

Hi Guys

Thanks for that

On Leakdown test the engine proves good. I have checked the belt and that is all ok.

It is deffinitely boiled fuel so I am thinking injectors now.

Got info a little while ago to change the injector loom (goes INTO the head) at £50 instead of £150 to get each injector tested. If this dont work its £150 for injector tests unless anyone knows how to do a PD injector!

http://www.clubgti.com/FORUM/showthread.php?t=178944 Interesting thread on cleaning these injectors. Makes me wonder if that's your problem - dirty nozzles. Is it possible to isolate each injector in turn and see if the white smoke stops?

What does this harness do exactly? I hate to see people wasting money swapping parts on guesswork but if you can afford it, I suppose it can save time if you get lucky.

Some reasons, though there's probably more but I've not come across them personally, for unburnt fuel.
Leaking injector
Poor spray pattern
Poor fuel
Timing

erm, can't think of anymore at this point.

Thanks Mike

Spoke to a guy who specialises and THE most common fault on the PD engine is apparently the harness as it goes through the head into the oil and muck. It is the harness to control the 4 injectors. The cam just pumps the fuel, the injection events are all TOTALLY controlled by the ECU.

****ing modern cars.

As the thing is apart and we have to fit new seals etc then the part is quite cheep. Esoecailly as there is no way to really test any of this - just swap it and see if it works

Time is tight and the owner has money fortunately.

Fair enough. If a new harness doesn't sort it, I'd advise getting the injectors individually tested. A tiny spec of dirt could keep a nozzle open, leaking fuel when it shouldn't.

If possible, take out the fuel filter and examine it and the filter housing looking for "glitter". If you see any, it probably means the lift pump has disintegrated and is spreading metal filings with the fuel. It's a worryingly common fault with modern diesels leading to very costly repairs.

Thanks mike

I have had a look at the filter and it looks ok - just very dirty - thought initially that it could have been a blocked filter but the smoke shows good fuel flow.

Could have a filter problem which has blocked an injector.

Other thing I found is loads of diesel in the cylinders - but this is from the 2 galleries in the head - feed and return. You remove the injector and the fuel drops into the cyinder

Thank goodness it's not the lift pump then!! But I did advise you remove the filter and check for swarf inside the filter housing itself, not the filter.

If that's the arrangement then could it be the source of the problem? Is there any way it can leak into the cylinders through a faulty seal? It would certainly cause the white smoke and make it run dog ruff.

Hi Mike

These cars have an all in one filter - there is no removable element (spin on or internal element) I had to take the whole thing apart to look.

It could be the injector seals - they are all being replaced as we speak.

Ah, my mistake, swarf is a really bad sign but leaking injectors from failed seals is another common fault I've read about.

So is it fixed yet?

Nope - still having trouble.

The stealer has it as they ought to be able to fix the issue -

new loom in the head and no fix - and they dont know what to do about the injectors - coz it couldnt be them!

So the car isnt fixed and they want £350 for not fixing it!

Going to get it back here and either disconnect the electric to each injector in turn or undo the rocker (which pumps the injector for furl pressure) and which ever one doesnt make it run worse is the dodgy injector. - MUCH easier with old style injectors, just crack the feed!

Ah well - will keep you posted what we find but its going to be early next week before I can even get the car.

Well finally got the thing fixed (ages ago - forgot to post)

This turned out to be an injector nozzle so we only got a jet not a mist of diesel - and a jet dont burn it just boils

With a PD its actually quite easy to test for faulty injector - take of the rocker cover and run the engine. Then pull off the trigger wires one injector at a time. If it gets worse it aint that one. Once you get to the right one the smoke clears. (dont forget lots of rags to catch the oil)

Had the issue again but it turned out to be a loose wire.

NOW we have an issue with the Gin injection - not seeming to pump.

The water meth was working well - then Rob ran out so filled it with water - which froze (duh no surprise there)

THEN he decided to use an ethanol mix and the cheepest with the most alcohol turns out to be Tesco Value Gin (37% or something)

But as its not pumping then we dont know how well this works - will let you know how gin does when we do!

What type of wi system are you using Steve?

Gin? tonic ice and a slice?...it'll be a lemon pip in the outlet or someone drank it all.

Surely meths is cheaper ..and probably tastier than super market's "value" range

Thanks for reporting back on the result and glad it's been sorted.

My WI was left primed over the cold period and I'm fearing the worst - cracked pump head

I'm on the ball when it comes to anti-freeze in the coolant but somehow never made the link to my newly installed WI kit and I'm so down on it, I haven't even bothered to look!

Could that be the problem with your system too Steve?

I agree, meth is a lot cheaper than Gin, what are you thinking???

Hi Guys, surely the Alchohol/Meth in the water mix will prevent freezing, as does antifreeze in the engine.
I guess its the concentration levels and temperature protection point, that is unknown.

Prefer Single Malt myself.

Sadly I looked it up:

* 24 proof (12%) liquor freezes at -6.7°C (20°F)
* 64 proof (32%) liquor freezes at -23.33°C (-10°F)
* 84 proof (44%) liquor freezes at -34.44°C (-30°F)

nah the Gin was the OWNERS idea (bloody teachers - always have to be right)

Mind you crappy meths is £3 for 500ml and the gin is £6 for 700ml so YES it is cheeper BUT I can see where he was going with the gin as it will be purer than the purple meths (no solids) BUT He is going to get a slice of lemon left on the tank next time out or lemons left on his windscreen wipers.

Ethanol in water freezes out so you end up with more concentrated ethanol and ice. (good way to concentrate the alcohol) Meths stays mixed dropping the freezing point and not freezing out in the same way.

We had good quality race meth but it all got used - mother tidied it up into smaller bottles to use for her china painting. Quite a few melted as shampoo bottles are just not the thing to put pure meths in and the rest got used on plates. (ALong with the antifreeze in shampoo bottles and screen wash in milk bottles, it has to be tidy dontcherknow and a 5 litre container with 1 litre left is just NOT tidy.)

I will look at the pump Saturday - think thats the problem but heres hoping its a loose connection. Probably is the same problem as you though Mike. I couldnt see a crack but there is no telling what damage has been done. The system is Snow performance - imported by Jabbasport.

Nige had a brilliant and simple idea and assisted by Pel we should be able to create a light weight WI system we can fit to LPG and nitrous converted vehicles.

I got a 230 litre barrel of 99.9% pure methanol for under £200 delivered. Works out a bit cheaper than you're booozey method.

BMW840, yes a mix would prevent it from freezing but like me, his was just water. I also have a 200litre barrel of water in my shed but that's survived without splitting - hope my pump did too.

TDIfurby, cheapest I found was 70p per litre @200litres or 60p @1000l, who did you get yours from if you don't mind sharing?

Came from a chemical supplier whos name escapes me right now. 70p a litre sounds about right, then you factor in about £70 to £80 delivery by truck.

Well the pump survived but the erth to it didnt

All working now

Without actual timing slips or dyno pulls we dont have any way to say it ACTUALLY improves things.

BUT - we ran 1/2 a bottle of nitrous and gin through on saturday and both Harry and Rapid Yellow think it improves things.

Now to fix the LPG leak......... (no smoking please)

Hope my old LPG kit is helping things for you.

I just shelled out 500 euros for the latest PD nozzles from Europe, which should supply enough fuel for me to reach 350bhp+ on diesel alone. Not quite getting there yet but I want 300bhp once my current rebuild is finalised.

Unfortunately the powershot didnt work well and checking on the powershot forums LOTS of people had issues keeping liquid LPG out of the lines if you had a full tank. And liquid in the line means a broken engine. It was not a risk I am willing to take (as I have to fix it)

We have used the rest of the kit but I changed the powershot to an evaporator unit (£75) that does the same job.

I think Rob wants to sort out a bigger turbo and nozzles sometime.

However I think he is better off not doing that and using the water meth, LPG and nitrous for the extra power as the furby is his daily driver. The LPG stretches his diesel as well making the car more economical. The bigger nozzles will probably drop his MPG - he is at 65mpg at the moment.

Yeah - mine hit 70mpg when using powershot system, but that was just because it was using less derv, but was not factoring in propane usage (standalone system as you know)

I am hoping I still get 50mpg+ from hi flow nozzles. The idea is meant to be they still do "normal" for normal driving but there is greater potential at the top end when you really want the big power.