vw Bora starting problems

[boxofmatches]

I have a 99 bora 1.9 tdi 90bhp, about four months ago we stopped at a shop for 5mins, returned to the car and it would not start, after about an hour the car started again, this has happened a few times since, now over the past few weeks the problem has got worse, the battery is strong enough, I have had it tested twice now, the engine turns over but just wont start, now here is the odd part, if I get jump leads and hook up to another vehicle then the bora will start, just today while at the local quickfit having the battery tested the car failed to start, the garage guy then went and got a 240v booster to start the car although the battery was strong and not lacking power, well the car did not start, then my Wife pulled out the jump leads and hooked to another car and the bora started on the first turn, a few months ago this again happened and I tried to start the thing for about an hour, this was before we realised that hooking up with jumpers would start the car, I then left the car for the evening and went back to it in the morning and the car started first time so I dont think I have a glow plug issue. Any suggestions greatly appreciated. Rgds, James

[whowhatwhy]

Damn..I was thinking glow plug issue there as well...I can't think of many reasons for a diesel with a good battery and glow plugs not to fire. Have you checked the fuel pump as the only other thing I can think of is fuel starvation (although the fact the car always starts when you attach another battery would suggest it isn't the culprit)

I still suspect the glow plugs as being the answer but below are the most common reasons for a diesel not to fire up:

* No fuel in tank
* Closed fuel shut off valve at fuel tank
* Fuel Injector pump kill lever or solenoid
* Air in the fuel lines
* Low cranking speed
* Water in fuel
* Clogged fuel filter
* Decompression valve left open
* Manual fuel pump or primer left open or jammed
* Water in cylinders
* Low cylinder compression
* Fuel pump failure
* Leaking or loose injector lines
* Fuel injection pump failure

Good luck!

[boxofmatches]

Hi, Thanks for getting back to me, I think the heater plugs would show up first thing in the morning and we have had a couple of -5 in the mornings over the past few weeks up here, as for air in the fuel line, well I did notice a few times while trying to start I did have a 2 inch air bubble in that see through fuel line, but why start when jumped up to another vehicle, I have now a fault code 0552, this tells me it is an engine coolant temp sensor (G62) but again, why start with jumpers attached, other suggestions have been, unscrew the banjo nut on the fuel filter, have a look and a pull on the starter cable to make sure nothing is loose, another is to replace relay 109. The cranking speed is good, there is no difference in the turning over if done on my own steam or with another car hooked via jumpers, once this car is going its perfect, but you just dont wana stop and switch off as I would have to leave it for a wee while tto get it started again.
Rgds,
James

[BigDogsWang]

I had a problem with my Audi last year, where for no apparent reason it wouldn't start. An Audi specialist told me to use the spare key, as the remote in the old one was not 'talking' to the immobilisor.

Swapped them over and never had the same problem. This however was on a 95 degree day, and could also have been down to a vapour lock. Worth a try though.

[whowhatwhy]

okay...tricky one. Have you tried just replacing the battery for a new one? Again i'm just thinking about your issues being resolved upon jump starting...perhaps the battery's circuit is damaged and isn't giving the correct voltage. How about just swapping batteries with someone for a while and see if that makes a jot of difference?

If you have an air leak in the fuel line this might explain some of the behaviour. When you turn off, the vacuum in the line would pull in air if there was slight leak somewhere and it wouldn't necessarily leak any diesel if it was a small fracture. BUT...that wouldn't explain the jump start!

Err...try the battery first. Then if no success you'll have to look at the injector pump, glow plug control relay and the solanoid.

[whowhatwhy]

BigDogsWang: Yes, that's a good call on the key immobiliser...I too have experienced this when the chip in the key wasn't talking to the car properly. Still confused as to why it always starts when jumped though.

[boxofmatches]

Hi all,
Thanks for all your answers, I have an update, just been out in the car , started fine, I stayed in the car while the wife popped into shops as we kept it running, also popped into Dundee VW dealer and he said the engine coolant temp sensor would cause my problem but the jump lead issue baffled him, well came home 30 mins ago and turned the car off, it started again, switched off then would not start, we have now noticed the light for the heater plugs, that yellow coil on the dash is not luminated at the times the car wont start, now if I leave the car for say 30mins to an hour switch ignition on, I will have heater plug coil luminated, go for a spin, come back and the car wont start and the coil will not be luminated, put jumpers on it from another vehilce and it will start, does this still sound like my battery is needing replaced, I have a buddy that got a new battery fitted to his tranny van last week, I will pop this on and take it from there and keep you all updated, all answers greatly appreciated.
James.

[boxofmatches]

Thanks to you and everyone else for the advice, well the car was serviced and all seemed to be going well, then last week the problem came back, I was working away and my Wife was stranded in town looking for someone to give her a jump start or leave the car for half hour or so then it would start. Mrs got it started and popped into the Dundee VW dealer, the tech hooked it up to the lappy for a diagnostic check, it came back as a poor battery, Mrs popped around the corner to battery dealer and got a new one fitted, well the car would not start and for the first time would not start with a jump or leaving it for a while, she then walked back to VW and the guy said it could be the 109 relay, Mrs bought one and the battery guy took his battery back refunded my Wife and fitted the 109, BINGO, the non-sense we have been going through since last summer was a �12.00 relay, car is fine now and I've thrown away the box of matches.
Thanks again to all,
Regards,
James