S40T starting problems

Hi folks,

I have a 1998/9 S40T from new and done about 60,000 miles (I love it!). However over the last year I have had a really annoying starting problem.
Sometimes it will start 'on the button' but most times it will turn over for several seconds (it seems ages!) before starting. When this happens there is a puff of black smoke from the exhaust and the engine will be 'lumpy' for a few seconds before settling down.
The problem can happen at any time, engine and/or weather can be hot or cold.
My Volvo dealer has looked at it twice with no result. Can you guys help please!

Let me know if you want more detail.

Thanks in advance.

[Dan F]

Hi.
Could be a couple of things...

The fuel pump, if you can hear a buzz when you put the key in and turn on the ignition then it is working and priming the fuel lines. If you don't hear it or it sounds erratic then it could be on its way out.

Or, the immobilser sensor ring on the lock barrel is getting worn and doesn't read the chip in the key properly and won't allow the car to start.

(The same thing is happening to my C70 at the moment. Sometimes it starts first go but other times it just turns over and will not fire. I am getting it sorted on Tuesday next week.
They instantly said that it was probably the sensor for the chip and asked for both sets of keys so they can program then into the new barrel sensor).

Could be the battery of course or the spark plugs....
Damn, that is 4 things. :)

It could be the ignition coils breaking down too. These cars use dual redundant spark direct ignition systems so no points or distributor.
D'OH!! 5 things.... ;-)

I will stop now, but hopefully that will give you food for thought.

Cheers,
Dan.

Thanks Dan,

The Dealer also thought of the Key Chips so I assume they tested for it but I will double check.
Also it had had (!) new plugs etc when being fully serviced a few weeks before - it needed a service and it was thought best to do this first since it just might have solved it, but it didn't.
They also had the Engine control unit off and cleaned all it's connections and also changed all the fuel filters.

It ALWAYS starts eventually so it seems to be an intermittent fault or one that the ECU can override but where to start.....


If I get it solved I will post the result.

[Dan F]

Getthem to test/try a different fuel pump. These do go and if it isn't working the car will obviously not fire.

Cheers,
Dan.

Hello mate,

I had EXACTLY the same problem with my 98 2.0T. I traced problem down to a split diaphram in the fuel pressure regulator that sits on the fuel rail with the injectors. Fuel was being allowed to weep past diaphram and down the vacuum pipe to the throttle body. I replaced it (£70 ish from Volve dealer) and now its spot on.

Hope this helps!
Laters

Great! Thanks very much - I will put this at the top of my list!

I intend to talk through with the dealer a list of the very good stuff you guys are coming up with. The dealers people are a good bunch and will openly welcome some help. If and when I get it solved I will post the solution.

Any other ideas are very welcome.

Thanks again

SOLVED!
Hi Guys - sorry it's taken time to get back to you but...The first dealer I was with had the car on 5 different days over a couple of months. They tried everything including the stuff you all suggested. In particular, putting a Gauge on the Fuel Pressure Regulator several times and said 'no problem since the pressure was OK'. I gave up and eventually decided to take it to another dealer who accepted the 'Challenge'.
He looked at my notes, the Database notes from the other Volvo dealer and especially your stuff. When I arrived he immidiately looked inside the Pressure Regulator vacuum tube! A smidgen of petrol! (such a simple check to do!) A new Regulator was fitted and the problem is SOLVED.
Thanks very much indeed to you guys. After months of frustration my S40T is now a joy to drive again.

[Dan F]

Cool.
Nice to hear when something gets sorted.

Dan.

Nice to hear its sorted mate. :-)