Starting problems - Audi A6 in 1996 VOLVO 850 TDI CD 1997 (Manuf 1996)

[Grandad Dave]

Engine D5252T

I have carried out a lot of work on this and really pleased with it, it suits my needs.

New battery fitted this morning. However, one annoying problem and help would be appreciated to try and solve this.

Starting Problems can be -

From cold - have to keep winding engine over on starter until speed picks up. Just sometimes it will start straight away after heat light goes out.

From hot - after the engine is stopped and I return to the car sometimes I have to turn the engine until speed picks up again.

Seems like air in fuel in FI Pump, I know this is a self bleeding pump on diesel engine.

To try and find the solution so far I have -

1. Renewed fuel filter.

2. Checked flow of fuel through 6ft of clear plastic fuel pipe (a) from tank to filter - no bubbles just clear fuel so - no air. (b) From pump to return pipe to tank. Same treatment - no air. So I now assume no air in the system which could cause this problem.

3. New timing belts fitted.

It seems like some sort of electrical fault in the pump or computer(?). I understand the pump is electrically timed but mechanically delivering fuel.

So my question is -

I do not understand computer minded vehicles. Do I need to go and get Percy hooked up to a computer, his umbilical cord, or can I work on him manually with some help from you all.

Would be grateful for any ideas e.g. change electrical components in fuel injection pump is something I have thought about.

Many thanks

Dave

[Peter D]

Not clear. That is not a VAG engine code. Regards Peter

[adamss24]

Hi, Peter, he is talking about the 5cyl. inline lump as fitted to the old shape audi 100/a6 also known as AAT(115Bhp)/AEL(140Bhp)... Iwould check timing if i were you, failing that, the coolant temp. sensor might retard the timing to such extent that it wont fire easy from cold. Ussualy the pump is either retarded or too advanced. If the aircon does not work, then the CTS is duff, check wiring or replace as necessary. Also, worn nozzles will give symilar simptoms to the ones described. Get them checked for spray/flow.

[Grandad Dave]

Thanks for your thoughts - really helpful.

I can see in the line - into the pump - air bubbles.

BUT - this is not coming from the tank because of my checking as described above using clear plastic.

Now I have cleaned off around the FIP I have discovered another piece of clear plastic fuel pipe which comes from filter unit to the FIP. I can see air bubbles in this pipe which comes from the filter housing.

So my deductions are the air must be sucked in around the filter housing or new filter that I fitted.

I am going to remove the filter housing and check for any cracks or failure there.

Any thoughts once again will be gratefully received.

P.S. When trying to start from cold it is white smoke.

P.P.S - Just thought I should say that when I purchased this last year, privately, I was told it is not the original engine and I have nothing to make me feel otherwise and it looks good.