Jump to content
Ratty43

2002 TD5 auto started, died, cranked for a while then fine

Recommended Posts

Evening all,

I'm new to the joys of TD5 ownership and in general it's cracking (I'm still getting used to getting better mpg at 70 than 60 and being able to hear things!)but....

As a bit of background the car has covered 138k miles with pretty much full service history and runs perfectly.

A couple of weeks back I stopped for fuel, climbed back in turned the key and it started and a second later died. I cranked it again and unlike the usual instant start it just turned over for a while with not even a try at starting. Left it for ten seconds and it started first turn. I assumed having changed the fuel filter that morning it was an air bubble and thought no more about it.

Today it did it the same thing to me, almost exactly the same although the engine was cold this time.

I'm buying a Nanocom this weekend if for nothing more than glove box peace of mind but I would appreciate any pointers or similar experiences.

Thanks in advance!

Share this post


Link to post
Share on other sites

Hi, wait for the nanocom and read fault codes, if you get something like "noisy crank signal" or other crank sensor related fault check the crank sensor's plug to not be corroded or loosened, meanwhile you can swap relays R9(main) with R8(heated screen) to rule out a dodgy mai relay cos that would give you crank-no start symptoms as well... also check the ECU red plug to not be full of oil, if it is you need a new injector harness(disconnect the battery before you play with the ECU)

Share this post


Link to post
Share on other sites

Thanks for that. Amazingly there's no oil in the loom even at the head connection as I had thought it might be that.

I've got a stack of relays from a D1 that I scrapped years back so I might swap them in as a check.

Occasional faults always are a pain although I can't complain as it beats being stranded!

Share this post


Link to post
Share on other sites

Are there any gurgling/swishing/whining noises from the fuel-pump? You could have on-their-way-out injector copper washers, allowing gas bubbles in the fuel-line which will cause poor starting/running.

If it doesn't start again, do the "fuel system purge" cycle [pump throttle pedal rapidly when you turn the ignition on, then leave it for a few minutes to purge - you should hear the in-tank fuel pump whirring] a few times to expel any trapped wind, then see if it makes a difference.

Share this post


Link to post
Share on other sites

Thanks. There aren't any noises from the pump other than what I assume is the relay clicking rapidly at the back when the ignition is switched on. The odd thing is it runs nicely and normally starts as the key is turned which makes me suspect it's the smoke in the wires!

Share this post


Link to post
Share on other sites

Today the Disco did nothing when I turned the key for a little while which has also happened a couple of times before. I assumed it was the solenoid contacts and have the kit ready to fit at the weekend but...

Having Googled that fault I found online that if the BCU fails to communicate the engine will start then die.

Given that it controls the starting and wipers and I've had trouble with both I'm starting to think this may be my problem.

I ordered a Nanocom tonight so hopefully that will flag any issues. In the meantime is the BCU like a 300 tdi spider where it can be taken apart and resoldered or am I likely to open a can of worms?

Share this post


Link to post
Share on other sites

The BCU is more complicated than a spider but it can be opened and inspected for corrosion/dry joints without problems, so is the interior fusebox(IDM) which can cause similar troubles, important is to disconnect the battery before you start unplugging any of them

Share this post


Link to post
Share on other sites

Thanks for the heads up on the battery. I finilly, after much sunroof fettling, tracked down my wet headlining to the windscreen seal last night. The flap of sound proofing over the BCU is wet thanks to that so the prime suspect is damp causing corrosion on the circuit board. I don't intend to pull the BCU out until I've read the EKA etc. Annoyingly my Nanocom was dispatched today and DHL show delivery for Monday.

When I do take it out I'll do a separate thread assuming I find something to repair in it.

Once again thanks for your help, it's much appreciated.

Share this post


Link to post
Share on other sites

Also take the fusebox out and check it if you have windscreen leaks. You may find a green furry mess inside, and that can produce nasty things in window and door lock circuits among others. Worst case it can hold the circuits on and burn out door locks.

Share this post


Link to post
Share on other sites

Thanks for that Bogmonster, I'll have look at it and give any suspect areas a clean. Windscreen sealing is on this weekend's to do list.

Nanocom arrived yesterday so I've just read the faults and got the following:

ECU.

1.5 Driver demand problem 1 (logged low)

5.5 Driver demand problem 1 (current)

16.2 High speed crank (logged)

22.1 Road speed missing (logged)

Slabs.

23.05 Shuttle valve switch electrical failure (intermittent logged 23 times) This I believe means I need to do the wiring repair at some point?

What interested me most is that the battery read through the instrument bit on nanocom shows 12.6 (it was replaced not long ago) but the BCU registers 11.6. I'm wondering if the leaking windscreen has corroded the earth to the BCU causing a voltage drop and the issues I've got?

Share this post


Link to post
Share on other sites

the root of the missfire is that crank sensor signal problem IMO.... read engine speed while cranking, if it's below 300 there's a problem with the sensor, the driver demand (throttle position sensor) would let it start just eventually loose throttle

Share this post


Link to post
Share on other sites

I can see the sense in that and have a new crank sensor on order. Although I don't have a missfire as such there is a vibration at 2500 while cruising at 70 which feels like a very faint miss.

I still suspect the windscreen leak has influenced the BCU so next weekend having read the codes I'll pull it out and have a look.

I sealed the windscreen inside and out with Tiger seal yesterday and washing it today I still had a dry headlining so fingers crossed that's one issue resolved.

Share this post


Link to post
Share on other sites

Just to add a bit, today I had the turning over and not firing. Left it 5 minutes and it started as the key turned. When I got home I plugged the Nanocom in and there were no stored faults. I'm pretty certain it's the BCU and water damage but will report back when I've found the time to take it out.

Share this post


Link to post
Share on other sites

Happened again today as well. This time I noticed the suspension height change light came on when I was cranking it.

Share this post


Link to post
Share on other sites

This means that the battery power dropped too much while cranking, check voltage while cranking and if it drops below 10v check battery main earth and make sure the clamps are well tigtened. it's possible that in this area is the whle problem, also what's the voltage with engine running?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy