absolutely crazy
 

well. Following on from my mates GV with the engine cut on hard acceleration. it was really annoying me so I took her out the other day and absolutely nailed it down a long stretch.... practically to the red line on the revs counter and held it there for a good mile or so. she didn't cut out. she just sailed along. so I thought you bitch lol. so I poked her again and proper thrashed it up a hill and proper gave the engine a stretch.... well blow me... its perfect now. no cutting out... starts first turn of key even on freezing mornings... you can put your foot down and she just pulls like a goodn.. 3000 plus revs.. no cutting out. tick over smooth as a nut. what the hell did I do just by braying it for a couple of miles. .. I am thinking there was a fuel blockage or mucky filter and blasting it has cleared it although he is gonna go get the fuel filter changed. I thought it was the filter housing jobbie but obv not. any ideas anyone????

Nick

Sounds like the "Italian tune up" method :cool:
Italian tuneup - Wikipedia, the free encyclopedia

You have probably simply burnt off hard carbon deposits from injectors*. This is the only way of doing it short of removing the injectors and having them cleaned ultrasonically. There is no known substance that can dissolve carbon, so it's just a waste of time and money expecting some "magic fluid" in the fuel to do the job. Hence the italian tune-up can work.

Leedsman.
* Current diesel injectors have complicated spray patterns and many holes, six for instance is quite common. They are backed by an injection pressure of something in the order of 25,000lb/sq". Anything distorting the spray pattern, such as a chunk of hard carbon will have a major effect on performance.

could the carbon deposits cause the engine cut on hard acceleration and surely this cant cause the low fuel rail pressure code I had. the low fuel rail pressure is why I was thinking fuel blockage somewhere or plugged up filter hence the italian tune up has shifted what ever was blocking it

Likely air in system but you cleared it. However you may have it coming back after leaving car standing for a while..

hey goggs. car has been running beautiful for nearly 5 days now. was stood for 2 days/nights and still perfect. In fact my mate says its like a new car. I drove it again today after 2 days stood and its perfect. I just cant believe a good thrashing has cleared it like it has. when you start it the starter motor barely spins twice and shes purring like a kitten. I hope others who may suffer similar can read this and try it them selves. all I can put this down to is an air lock in the fuel system somewhere that has been blown out. he usually drives like theres a bomb under the accelerator because he thought keeping the revs down would be good for the engine. he has changed his mind and is going to give her a blast once or twice a month. ... still gobsmacked that a simple thrashing has cured this three year long problem. marvelous I say :)

In all fault location, it's what works that matters.
"The proof of the pudding is in the eating".
Let's hope the engine is still running the same six months hence.

Leedsman.

Mines getting treated too nicely, prob should be kicking its ar*e as well. But its going fine, well except for little things, but great mover.

My GV was running fine when I got it (like 40K km ago) but the engine was slightly rough when running idle.
I performed more or less the Italian tune up together with some injector cleaner and the idling was fine after that.
Since then I use my GV 50/50 for small towntrips and long highway trips.
In town I surely have a "sporty" driving style and on the highway I ride ~130km/h on average (where possible).
I can state with quite some certainty that the engine runs better, smoother and more powerful compared to when I just got the GV.

That does "proof" my theory: "never buy a car from old ladies" :D

most of my driving is at 50mph (80kph) due to speed cameras all over our local main roads, but it is a speed that is neither a 4th gear or a 5th gear speed. if doing bang on the speed limit the car is ok but any slower by even 3mph I have to change down and sit at around 1900rpms, it's a good 8 mile stretch so really wish it was back up to a 60mph limit really lol

I have the same problem on 80km/h roads :)
Its not 4th and not 5th gear, but for "heating up" the engine a bit I sometimes stay in 4th for a while.
If I go up in speed to ~85km/h I 'just' avoid fines and 5th gear is smooth enough.

its not just my GV then :) one of the joys of a manual hey

If there's speed limits everywhere, no decent long straights without cars and not able to get enough revs on the motorway. How about just driving along in a low gear now and again revving it at about 4,000rpm. Or do we need heat, engine pulling hard to clear out the cobwebs.

4,000 rpm might be a bit harsh on my GV lol I do stay in 4th a lot at just over 2,000 rpm and going up the gears I take her up to 2,500 no more than 3,000rpm. Does that place me in the grandma drivers club? :)

or grandad drivers club .. :D
You too might consider revving the GV up every now and then to avoid turing your GV into a clogged slow hockeymom car :p

Posted last August - all diesels like to be 'ragged' - its the automatic ones that are difficult to rag.

Hmm must change my name to an old grandad name like ''Morris''
maybe I could do a few miles at a smidge over 3000rpm ;) that is where the engine is at its best performance wise anyway so no need to make it work too hard and risk something breaking, don't ask why but if it was petrol I have no issues taking them to the red line but with diesel I always been taught to not drive at high revs for too long because they have a must higher compression ratio. As a consequence, more heat is generated putting extra demands on the engine cooling system. diesel engines usually fail 40% more on cooling related problems because it cannot stand prolong overheating. This is why the cooling system is a high maintenance issue.
I have only just fixed my cooling system issue (water pump & connector hose from water pump to oil cooler) and although I am 99% certain is fine, that nagging 1% just tells me to not over do it haha


sorry this reply is longer than I intended

The 'cruise catch up' on the auto CRD is set to 3k anyway. Its not the RPM per-se its the heat generated over the time. Caveat emptor doctrine still applies. just watch the gauges like a hawk - as you say - if in doubt - don't do it !

If the overheating is what worries you.. I would start revving as soon as the temp gauge is on 1/4th (engine is warm and ready to perform) and stop revving as soon as you get near the red zone.
That way you risks on damaging/overheating are minimized (imho).

The most stressed part of diesel engine is the cylinder head and gasket. Compression ratio is between 16:1 and 18:1 depending on the design for NOX emissions, whereas ratio for petrol is almost always under 10.5:1 due to knocking problems. Furthermore, in principle diesels are unthrottled (sometimes light throttling for emission control) therefore the compression pressure is always much higher with a diesel. As most car diesels are turbocharged, the compression pressure is yet higher still at full power.
If you give a diesel an italian tune-up, it's wise not to do it for too long as there could be a blown head gasket. Certainly revs is/are the key to success here. It is universally agreed if you are GOING to do an italian, do it just before you change the engine oil.
While driving normally, every week or so I give it a "full-bore experience", hang the fuel consumption. But as Goggs says, driving around nowadays is like trying to swim through treacle with all the traffic.

Leedsman.