warm start strangness

[swalker]

Hi All,
Strange one, the car will start and run fine all day everday - except if you leave it for 2 or 3 minutes when fully warm. it will crank twice maybe and stop, or just not go at all.
It happened 3 times so far, only once with me. that once i didnt let the glow plug light out before cranking, so i am sort of thinking fuel pressure on the injection rail?

but here is the thing, when it does happen the car gives out stink about the brakes when it happened to the wife it had a big red ! in the center of the dash, when it happened me it did say something about EPB maybe ESP and it was shut off.
cant say the first time as this was with the MOT inspector....

any ideas? it will stop and restart fine after it gets going?!?!

[swalker]

Ok so some more detail same issue only I can now say the first odd thing was a delay in the glow plug light then it didn't go out and the fault auto brake release defective drive slowly to nearest dealer. Only thing is bloody car won't start.. .. gotbot going by locking up waiting till the hazard switch went out ( electrics asleep?) Then off she went.
The handbrake worked fine I tried putting it off and on a couple of times to no avail. I don't tend to use the auto brake maybe I should and it may cure the problem? Or brake it altogether.. .

[dan2485]

Do you have all the ignition lamps lit ok?

As the J329 realy maybe on its way out.

Have you done a scan?

[Lukenkarl]

Water ingress possibly. Have you checked the usual places?

[swalker]

Thanks for the replies,
It went all funny this morning cold which got me thinking about the water ingress.
I had that fault a week or 2 ago where the plenum had filled and she wouldnt start, drained water and away she went.
Ever since i have been meaning to open up the ecu box and check for dampness corrosion on connectors.

I got a chance to have a look, the doffer, widget (she wee?!?!) at the wiper was blocked but there didnt seem to be any dampness in the ECU or the other side. but i didi clear out a couple of damp handfuls of decomposing leaves.

and it only started after an MOT wash were i remember now the guy having a go under the bonnet.. and i did figure out anytime it failed to start the car was not level, twice nose up, once passenger (left) side on a kerb, but just before had to brake hard, so that is adding fuel to the water theory....

Thanks again

[niall campbell]

my A6 refuses to turn the engine over until I let the glow plug light go out, this has happened to other people in here

I put the ignition on, put my seat belt on & then start the car.


As for the brakes, just think its related to not starting ....................



Go for waiting for the glow plug light to go out before starting ............................................ then monitor the brakes


cheapest option

[swalker]

yeah i am picking up a strict starting regime is required?!?!
i do wait for the light to go out, however if it delays coming on the brake faults will kick in before the light goes out and i touch anything..
finger crossed it seems to be starting quicker (shorter time) since i cleared it out, must make a note of turn over speeds possibly pointing to starter / battery?
on the couple of times it did fail it could crank until i lift off the clutch, or randomly crank twice and stop. I have checked the jump start points they are fine (hmm not black but I didn't strip and clean), is there any other connection that may fail?

thanks again

[B5NUT]

When was the battery last changed?

[swalker]

unknown, i have thought of the battery, however discounted it as the engine never struggles to crank, or lights dim - the normal symptoms of a poor battery.
i did wonder do these cars have a capacitance bank or something?

Just added a screen to my torque app with RPM and Volts at the control module. will log a few starts and see what happens.

[gupsterg]

@swalker

Reading your opening post sounds very similar to what was happening to sparker, ref this thread it may or may not help you, where A8 Tech starts posting is best to read.