A4 1.9 TDi 1997 'R' (hard to start from cold)

The Milkman · 13-09-09, 12:41 AM

A few months ago my A4 started to become a pain in the arse to start from cold, it's not the glow plugs, as i've tried changing them with no avail.

I've tried turning the ignition on and off again a few times to see if the glow plugs are not getting a chance to heat up, but still the same problem.

Once the car has heated up, it's no probs, first kick. But with the winter coming in, I really need to get it fixed. There's a chickens chance in Thailand it'll start in sub zero temps.

Any suggestions welcomed. Thanks in advance.

kully · 13-09-09, 06:32 AM

My 80 tdi has developed the same problem, and once it does start it hunts for a while and sometimes cuts back out again, also the engine is sometimes smooth, and then starts to run lumpy, proper frustrating

The Milkman · 13-09-09, 06:50 AM

Someone suggested the glow plug relay, and someone else suggested a problem with the ECU itself.

It turns overfor about 10 seconds before it finally fires, then you get an almighty plume of smoke as if there's a nearby forest fire.

On another note.

Has anyone ever owned an older A4 and had problems with the doors not latching properly?

Mine, my dad's and my brothers all had the same problem.

kully · 13-09-09, 07:20 AM

Ive changed yhe air mass meter, with no joy, so ive got an ecu relay to change once I find where its location is, Ill also see if there is a relay for the glow plugs also,

smaxted · 14-10-09, 12:30 AM

What colour is the smoke? Nice and thick and white??? Your glow plug on time is controlled by the ECT sensor.....if the sensor is biased hot then the glow plugs will never come on.

BW2309 · 14-10-09, 07:41 AM

The glow plug relay is a fairly common issue and only causes issues with the 90 and 110TDi's. The later PD equipped engines don't really need glow plugs due to the pre injection cycle and massive injection pressures.
If it helps I could email you the test procedures for the glow plug relay. Also, if you have access to VAGcom it should show any fault with the relay.
I know it sounds daft but start with the simple bits - check all fuses!!

If the glow plugs are not coming on it will take ages to start. The reason it does eventually start is that some of that un-burnt fuel builds up in the cylinder, raising compression and in turn the internal air temp. As the air temp rises it helps the fuel burn.
You've not had a cam belt fitted wrong have you?? It is VERY common for timing belt to be on wrong and the pump timing be out, this can reduce it's ability to start from cold too! Just pop ya cam belt cover off - if there's tip-ex marks on the cam puley it's on wrong!!

13-09-09, 06:50 AM	#3
The Milkman Empty Wallet :( Classic Audi Club Member Join Date: Mar 2008 Location: Kilmarnock, Scotland Posts: 755	Someone suggested the glow plug relay, and someone else suggested a problem with the ECU itself. It turns overfor about 10 seconds before it finally fires, then you get an almighty plume of smoke as if there's a nearby forest fire. On another note. Has anyone ever owned an older A4 and had problems with the doors not latching properly? Mine, my dad's and my brothers all had the same problem. __________________ 1984 Audi Ur quattro [A10VOT]

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13-09-09, 06:32 AM	#2
kully Grown up member Classic Audi Club Member Join Date: Aug 2008 Location: Walsall Posts: 941	My 80 tdi has developed the same problem, and once it does start it hunts for a while and sometimes cuts back out again, also the engine is sometimes smooth, and then starts to run lumpy, proper frustrating

13-09-09, 07:20 AM	#4
kully Grown up member Classic Audi Club Member Join Date: Aug 2008 Location: Walsall Posts: 941	Ive changed yhe air mass meter, with no joy, so ive got an ecu relay to change once I find where its location is, Ill also see if there is a relay for the glow plugs also,

14-10-09, 12:30 AM	#5
smaxted Newbie! Join Date: Oct 2009 Location: Ontario, Canada. Posts: 13	What colour is the smoke? Nice and thick and white??? Your glow plug on time is controlled by the ECT sensor.....if the sensor is biased hot then the glow plugs will never come on.

14-10-09, 07:41 AM	#6
BW2309 Banned Join Date: Sep 2008 Location: Derby Posts: 1,245	The glow plug relay is a fairly common issue and only causes issues with the 90 and 110TDi's. The later PD equipped engines don't really need glow plugs due to the pre injection cycle and massive injection pressures. If it helps I could email you the test procedures for the glow plug relay. Also, if you have access to VAGcom it should show any fault with the relay. I know it sounds daft but start with the simple bits - check all fuses!! If the glow plugs are not coming on it will take ages to start. The reason it does eventually start is that some of that un-burnt fuel builds up in the cylinder, raising compression and in turn the internal air temp. As the air temp rises it helps the fuel burn. You've not had a cam belt fitted wrong have you?? It is VERY common for timing belt to be on wrong and the pump timing be out, this can reduce it's ability to start from cold too! Just pop ya cam belt cover off - if there's tip-ex marks on the cam puley it's on wrong!!