Revving Diesel

Ross · Post by **Ross** » 26 Mar 2010, 22:31

Just won a 1991 205 td with 88k on the clock for £102.00 - with mot's to prove - haven't told the wife yet but that's another story for later

It seems the problem is the diesel engine revs itself (as described in advert) is it likely the problem is due to an air leak in the system - are there any other issues which may cause the same problem.

Haven't picked it up yet so haven;t heard it but have read through previous posts and air definitely seems the likely problem any likely areas to look for a leak .

Any ideas ?

Thanks
(good to be back on Frenchcarforum - it is the best I have used to date)

DickieG · Post by **DickieG** » 26 Mar 2010, 22:40

It'll be down to engine oil entering the inlet manifold/combustion chamber, the big problem with that is that the engine might run completely out of control with the only way of stopping it being to stall it. Is the oil over filled? It won't be an air inlet leak, diesels air inlet flow should not be restricted. Is the exhaust smokey? (turbo seals)

dieselnutjob · Post by **dieselnutjob** » 26 Mar 2010, 22:45

if it's running on engine oil it will be knocking and smoking badly
air leaking into the fuel supply can cause wierd things to happen, but it can also be a fault in the injector pump
I have seen a Lucas pump where the main bearing started to break up and a bit got stuck in the mechanism inside causing it to idle at 2000rpm
lucky really because probably it would have suffered cambelt failure otherwise

Ross · Post by **Ross** » 26 Mar 2010, 23:46

On a brighter note have contacted the seller and evidently its been "running fine " today and given the nileage on a diesel it would suggest its not running on engine oil - surely he would have noticed the noise and smoke.
I reckon I will get the car home - check the filter and oil and run it up before I post some more - at least it will give a better picture of the problem.
Thanks for the replies no doubt we will sort it - lol

ever the optimist
Ross

dieselnutjob · Post by **dieselnutjob** » 27 Mar 2010, 10:48

the filters that have a priming plunger on the top often fail letting air in. if so a new filter housing will be needed. this happened to me once and the AA mine covered the plunger with cling film and wrapped an elastic bound round it to stop it sucking air past the membrane inside which had split. it got me home
It can be well worth replacing the fuel line between the filter and the injection pump with clear pipe so that you can see if there are air bubbles in there
also the small bore rubber pipes between the injectors and back to the pump ( the leak off return pipes ) can perish letting air in and it's a cheap and quick job to replace them

spider · Post by **spider** » 27 Mar 2010, 11:36

Same model as mine

Agree with primer letting air in, I ended up fitting something completely different (I'll get you a pic if needed)

The 'fuel heater' on the back of the block is bad sometimes on these, I bypassed mine and made a new one (again, I'll get you a pic) . Be aware if you bypass this to ideally use new rubber hose, don't just join the removed ends together, but watch it as the 'replacement' fuel hose can sit too close to the turbo and exhaust if you are not careful.

Ross · Post by **Ross** » 27 Mar 2010, 20:54

Still trying to sort pick up but theres a bit more info - evidently the engine revs itself now and then but creates white smoke when doing it - the rest of the time it runs fine - even tickover is fine? the seller (who seems a reasonable bloke ) seems to think the white smoke is due to overfuelling but readily admits he isn't a diesel mechanic (that makes both of us).
If I saw lots of white smoke I would have thought possible headgasket but he seems to think there are no other symptoms to indicate a problem with the head gasket and the problem only started after the car had been standing for a while unused.
Can't wait to get started on it -

Still a great forum - should never have bought a ford - lol

dieselnutjob · Post by **dieselnutjob** » 30 Mar 2010, 07:50

white/grey smoke can also indictate retarded injection timing. it will smell smoky whereas steam doesn't smell
I suppose that if the pump is running on an air/fuel mixture it could mess up the timing but I'm only guessing

Post by **CitroJim** » 30 Mar 2010, 11:49

Hi Ross, good to see you back!

On the TD with a Lucas pump there is yet another cause of running on and revving. The diaphragm in the pump boost overfuelling device can fail and allow oil mist from the induction tract to get inside the pump and contribute to the fuelling in an undesirable way

White smoke could well be present although if this, it is often tinged with blue as well.

Disconnect the boost sense pipe between the inlet tract and pump and see if the problem goes away...

205TDs go like the wind. They're almost scary and will give a 205GTi a good run for its money

Well worth £102!!!!

It'll put a smile on your face and your wife when she drives it...

Ross · Post by **Ross** » 31 Mar 2010, 20:29

Thanks for the welcome Jim - still got a Xantia Diesel but bought a Granada 2.5td - no cam belt as its geared but but should have stuck with the VSX TD - much better car
Always wanted a 205 TD as a project because I heard they were good and I reckon its worth doing - just got to pick the thing up - still its a good excuse to get back on here - happy days