Help 80 TDI Terrible Cold Start White Smoke

StompOn · 02-07-09, 10:14 PM

right here we go my 80 tdi is a pig to start in the mornings just now a good 30secs of turnin over untill it springs into life and a load of white smoke comes out the back first thought being white smoke cold burnt diesel so glow plugs so i replaced all them with denso ones still had the same problem so then i went for the relay 202 i got a genuine proper one from audi and no still same problem once its been running for 5mins or so and you stop it it will start with a flick of the key no problems no smoke my head hurts on this i checked all the fuel pipes in the engine bay making sure all is tight no fuel seems to seep back thru the system when ya switch it of im well ad truly stuck

anyone know of anything? any help would be great thanks

audi80 · 16-08-09, 09:18 AM

you can check vacuum power of your pump by
1.direct connect your diesel fuel tube (not through fuel fillter)
2.start your engine again
3.if it don't have white smoke that because your pump's cylinder is not fit.it cannot suck the fuel.change it
4.if it still have white smoke,you should accelerate engine to 3500 rpm then your smoke change to black color.that because your spring is in inject is too solf you should change it.
5.if not thing maybe change your gasket(O-ring) in inject

Nice to meet you
Meechai wang
biodiesel05@yahoo.com
+66 81 9911335
(Thailand)

PhilGee · 16-08-09, 01:45 PM

Possibly an injector fault? Not really up on these VAG diesels but i know a similar fault occurs with other manufacturers and its a sticking injector not spraying fuel correctly so doesnt burn/ignite properly. Maybe try an injector cleaner for what they cost but may require the injectors getting looked over by a specialist.
Just a possibility. Best doing the easiest things first that dont cost alot before you jump straight in and spend a small fortune.
Phil .

BW2309 · 16-08-09, 05:59 PM

Not had the timing belt changed have you without use of the proper tooling?
The injector pump on these must be set dynamically after every belt chnage. If the timing is too rearded it will really struggle to get the cylinder pressure up enough to start from cold. You see, the VAG TDi's have a relatively low compression ratio and a clever pre-injection cycle that burns a small amount of fuel before TDC, this raises the cylinder pressure enough for a complete burn but keeps the engine relatively quiet and stress free.

You can check the pump timint on VAG com easily. The cam pulley is adjusted during belt change too, this must be correct!!

If pump timin OK then must be something on cold start electronics or clogged injector. Hope this helps!

16-08-09, 09:18 AM	#2
audi80 Newbie! Join Date: Aug 2009 Posts: 5	diesel fuel pump vacuum you can check vacuum power of your pump by 1.direct connect your diesel fuel tube (not through fuel fillter) 2.start your engine again 3.if it don't have white smoke that because your pump's cylinder is not fit.it cannot suck the fuel.change it 4.if it still have white smoke,you should accelerate engine to 3500 rpm then your smoke change to black color.that because your spring is in inject is too solf you should change it. 5.if not thing maybe change your gasket(O-ring) in inject Nice to meet you Meechai wang biodiesel05@yahoo.com +66 81 9911335 (Thailand)

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16-08-09, 01:45 PM	#3
PhilGee Grown up member Join Date: Aug 2009 Location: Darlington, NE of England Posts: 62	Possibly an injector fault? Not really up on these VAG diesels but i know a similar fault occurs with other manufacturers and its a sticking injector not spraying fuel correctly so doesnt burn/ignite properly. Maybe try an injector cleaner for what they cost but may require the injectors getting looked over by a specialist. Just a possibility. Best doing the easiest things first that dont cost alot before you jump straight in and spend a small fortune. Phil .

16-08-09, 05:59 PM	#4
BW2309 Banned Join Date: Sep 2008 Location: Derby Posts: 1,245	Not had the timing belt changed have you without use of the proper tooling? The injector pump on these must be set dynamically after every belt chnage. If the timing is too rearded it will really struggle to get the cylinder pressure up enough to start from cold. You see, the VAG TDi's have a relatively low compression ratio and a clever pre-injection cycle that burns a small amount of fuel before TDC, this raises the cylinder pressure enough for a complete burn but keeps the engine relatively quiet and stress free. You can check the pump timint on VAG com easily. The cam pulley is adjusted during belt change too, this must be correct!! If pump timin OK then must be something on cold start electronics or clogged injector. Hope this helps!