I recently bought an R-reg 306 1.9 D Turbo (no history) and am rarely on a motorway, but when I am it just gets to 90 - 93 mph and will no go any faster - WTF!
the revs aren't going mad or anything, and the turbo works fine up to
90mph, it's like it has a limiter or something.
I've just bought some 10k Diesel (see
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to decoke everything, assuming I can find the turbo to spray it in, but I don't know if it would help my problem.
"10k Boost is dispensed as a fine spray in to the air-intake system, whilst the engine is running, the air flow carries it through the air-inlet into the combustion chamber. 10k boost then passes out of the open exhaust valve through the exhaust itself, decoking every surface it touches."
What a load of bollocks! No 'protective spray' is going to survive passing through the combustion cycle, and be able to 'decoke' the echaust system on the way out.
It's snake oil mate - the best thing you can do is keep it serviced, especially change the oil often. All these teflon wonder products are basically fancy cans of kerosene.
Your car should be good for 100-110, so it needs to go into a garage for a check-over. Likely to be fueling related, but pick a small expert who'll have time to look at it carefully.
I got a petrol and believe me about 100mph is swift in a car that size. Been at 120mph on M1 (late at night) and you wouldnt want to go much faster. Gets a bit hairy!!! I think its down to the wheelbase, cos its short it doesnt sit that well at high speed.
Interesting idea Neil. I have absolutely no idea what happened to my car in the 5 years of its life before I bought it - it was from an auction and didn't even come with a log book! However the gearbox feels a little stiff so I'd be surprised if it's new.
Someone has also suggested a boost leak in the fuel pump (split diaphragm). Wish I knew more about engines!
There's a thin hose going from the intercooler to the fuel pump that basically tells the fuel pump to add extra fuel when the turbo is giving boost. If the pipe is split the fuel pump doesn't sense the boost pressure and doesn't add the extra fuel required to make full power. The diaphragm is inside the fuel pump. The pressure in the hose moves the diaphragm which in turn moves a shaft in the pump that inceases the fuelling. It is possible to check the diaphragm for splits etc. but it requires some disassembly of the pump and probably isn't a good idea if you haven't done this kind of thing before.
Have a look over the fuel pump to see if any of the adjustment screws appear to have been tampered with. Especially any marked with yellow paint if you have them. It is possible that the maximum fuelling was turned down to reduce the smoke for an MOT. If you have the Bosch pump the important screw is shown here
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