Very occasional fail to start

[PranK]

Hey peeps,

On 2 or maybe 3 occasions now over the 2 years I've had Bozo, er.. my Bora, the car has failed to start.

Its almost as though the immobiliser has not been disabled, or the fuel pump has not started, because theres just no firing when its being turned over. If I wait only 30 seconds to a minute (ie, just turn around and lock the kids in their seats) then it starts fine.

My concern is that something is dying and that it will eventually not start at all.

Anybody else had this?

Christian

[Stan]

same on my golf mk4 in the last 2 weeks - twice.
dunno what it was - first time i roll started it, second time it fired about 20 seconds later.

must remember to take more notice of the fuel pump priming sound when the door is opened....

[JustCruisn]

same on my golf mk4 in the last 2 weeks - twice.
dunno what it was - first time i roll started it, second time it fired about 20 seconds later.

must remember to take more notice of the fuel pump priming sound when the door is opened....

The fuel pump will not prime if the Cam Position / Hall sensor is playing up.

Also if you leave the door open too long the fuel pressure drops, and can be hard to start.

[VR6man]

Same here on my Bora V5, very random.
Very frustrating when your trying to pin point the problem.

[Stan]

aarrgghh - happened again, whilst driving home tonight.

turning into my street it just cut out like it was switched off, clutch started on the roll and it fired and ran.... mystery

[h100vw]

aarrgghh - happened again, whilst driving home tonight.

turning into my street it just cut out like it was switched off, clutch started on the roll and it fired and ran.... mystery

Have you looked at it for faults? Does sound a bit crank position sensor, except the bump start bit. Have good look at all the wiring after a scan.

Gavin

[Stan]

thanks Gav, will scan tomorrow

[PranK]

Also if you leave the door open too long the fuel pressure drops, and can be hard to start.

As in, the drivers door?

[JustCruisn]

As in, the drivers door?

Yes. 6

[PranK]

Yes. 6

Ok, so something is either wrong with me, or wrong with everybody else... But ... How can leaving the drivers door open drop the fuel pressure?

[JustCruisn]

Ok, so something is either wrong with me, or wrong with everybody else... But ... How can leaving the drivers door open drop the fuel pressure?

The fuel pump primes when you open the door. It does it once only. So if you leave it a while, like 1hour. The fuel pressure fades away.
When you go to start the car there is low fuel pressure and it can be hard to start. It will probably start but can take a few more cranks than usual.

Anyhow this is off topic, it is not the problem stan is having.

[PranK]

But it's my thread.

[JustCruisn]

But it's my thread.

Oh so it is. Sorry!

[VDUB-BUD]

The fuel pump primes when you turn the ignition on as well.
I had problems with my car not starting 1st go on hot days, it end up being the coolant temp sensor which was replaced 1 year prior. it was a cheap ebay one.

[Stan]

ok , i found the solution to my problem, with Gav h100VW's help.
He felt it was related to the injector loom in some way, as there were no other faults, complete fail of starting, nothing on vagcom...

Check all connections to the injector loom. With the car running, shake and poke as the loom, joins, connectors (carefully...)

I eventually grabbed the covered loom that comes from under the scuttle, that the ecu loom feeds into, and goes under the airbox.

A mild shake of this caused a misfire, and with persistence, i got the car to stop. In my case i have a home built connector in there, that must have a loose fitting, wire, something. In an unaltered car, I think there is still a connector which might be worth a look. Mine is home made because two plugs were incompatable.

To get at it , the air cleaner needs to be removed, and the top of the channel unclips/slides off

Alternatively the loom goes through a series of relays and fuses that the fuel pump relay is involved with as well.

Hope some of this might help. I am yet to do the surgery on the car, but I now know where to start.