1.4 TDI starting problem

T

twiddler

Member
Hi, this is my first post on the forum since buying my 2001 1.4 TDI in April and I really hope someone can help.

I've got a problem with cold starting, this started to happen about 2 months after I bought it, up until then it was fine. The problem is: When the engine is cold (only cold) I have to crank it for some time before it finally splutteres into life in a cloud of smoke. After it warms up the smoke clears and starts fine. Now I know a bit about cars, I changed the cambelt myself on this and the nearside shock.

First I suspected a clogged fuel filter so changed that; no difference. I bought the diagnostics cable, ran a test and it came back with error code 01406 - No Flame. This suggested air in the fuel line. This is probable; since the pump sucks rather than blows it could easily suck air in through a weak joining clip, but I've searched the car from end to end and from what I can see they look fine. I was advised to put some clear pipe up near the pump and look for air and sure enough I could see air bubbles in the fuel. This would fit with the symptoms - (air build up over time at the pump input causing an air lock - bleed issue). Also I think I've found a little (poor) workaround: by flooring the accelerator pedal just as I turn the key it appears to pull it over the dead spot. Though revving a cold engine can't be good for it. It certainly doesn't sound like its doing it any good. And desn't always work.

I've looked at all the posts on the forum that are similar - crank sensor / temp sensor etc and can pretty much discount these although I haven't totally written these off.

The temp sensor is a possible. If this fires up the glow plugs. I've yet to put a meter across the glow plug supply and see if they are getting a voltage and for how long? Is the temp sensor that is often refered to the one in the fuel line or in the bottom of the water tank?

If anyone has any suggestions they would be dearly welcome!

Many thanks
 
The engine coolant temp sensor is on the back of the cyl head - http://www.a2oc.net/forum/showpost.php?p=80965&postcount=17
I think the 01406 'no flame' fault code relates to the Webasto auxilairy coolant heater rather than the engine. The heater only fires up below 6 degC so should not affect cold starting.
In the summer the engine should start fine without the glowplugs operating so my best guess would be the coolant temp sender as this influences cold start fuelling.

Cheers Spike
 
based on my experience - a duff crankshaft sensor affects starting when the engine is warm, not cold.
 
Gents,

Many thanks for taking time to get back, I really appreciate it. Thanks Spike your pic led me to the right sensor but changing it has not fixed the problem. I still think air is geting into the fuel line and I need to find out where. There a plenty of joins between the tank and the pump I'll just have to go through them all!
 
Check to make sure the fuel filter housing is secured correctly.

When I first got my car I had it serviced and they never refitted the drain plug and seal properly and it was drawing air in, and was a right pain in the backside to start, until I figured it out.

Had to buy a new filter / housing but once fitted car was fine and has never had a prob since.

John
 
Update

Okay, so quick update - maybe someone will make use of this one day. I just got back from Cornwall, driven 700 mls round trip. Coming back in teaming rain I wondered if this can't be air in the system because otherwise water would be getting sucked in and that would kill her. So I hade the bonnet off and checked continuity on the glow plugs, one was OC. The other two read 5 - 6 ohms. The clouds of white smoke make me think un-burned fuel. Thing is I've now checked the voltage - no volts at the glow plug end but there are volts on the relay and fuse. I would have expected 12v on the plugs, is there something I'm missing?
 
Back Again.. still with the same problem.

Question: does anyone know of any issues with the quick release connectors on the fuel hose? The filter has these on either side of it. I have a theory that these (or one of them) maybe the source of the air getting into the fuel line. Anyone out there who might have any experience of these having problems would be warmly welcomed! I'm beginning to lose the will to drive..
 
Progress...

I took some advise and put a piece of clear hose in the feed and output hoses of the fuel filter and sure enough there was air pulsing at the out with just a tiny stream of bubbles on the fuel supply side. Looking around the back I came across the Fuel Changeover Valve. I've noticed this is making a regular ticking sound - quite loud. It starts ticking about 1 minute after the engine starts. Does anyone know if this is usual and or whether these units are prone to some sort of fault? They were removed shortly after mine was manufactured.

All commens greatly appreciated!
 
twiddler said:
Progress...

I took some advise and put a piece of clear hose in the feed and output hoses of the fuel filter and sure enough there was air pulsing at the out with just a tiny stream of bubbles on the fuel supply side. Looking around the back I came across the Fuel Changeover Valve. I've noticed this is making a regular ticking sound - quite loud. It starts ticking about 1 minute after the engine starts. Does anyone know if this is usual and or whether these units are prone to some sort of fault? They were removed shortly after mine was manufactured.

All commens greatly appreciated!
Click to expand...

A couple of club members have had problems with the metal canister type fuel filters fitted to early cars. The problem seems to relate to fuel drainback which makes the cars difficult to start after standing for long periods. I'd guess it could be caused by faulty crimping / welding of internal pipes or baffles, particularly on non-genuine filters. Could this be the source of air in the fuel lines?

Cheers Spike
 
Last edited:
Hey Spike, thanks for staying with me on this one! Actually, I think I've got to the bottom of it. My car was manufactured in Jan 2001, in September they changed the design of a fuel change-over valve, mine has 4 connectors and sits up on the back of the tank. The later models only had 2 and I think they done away with it altogether after a while because, the replacement parts are two hoses. I've not got all the details, but my unit is switching with a constant ticking sound, which cannot be right as its only supposed to switch if the fuel temp reaches 72c. What would be useful is to see how a more recent one is connected. Its been a long process and I hope it helps some one day! Not that there can be too many early versions out there which did not have the mod done in their warranty period. If you can find any photos of a current fuel change-over valve that would be superb.
 
Check out (P38 onwards) the attached link for details of the early fuel supply layout. This shows the change over valve is on the top of the fuel filter and simply returns hot fuel from the engine, through the filter then back to the injectors. This stops fuel going through the cooler until the pre set temp is reached
http://www.volkspage.net/technik/ssp/ssp/SSP_223.pdf

Cheers Spike
 
Spike,

Thanks again for helping me with this one.

For some reason the car has been starting fine recently but the smoke is just as bad or worst even. This only occurs when its cold as soon as it hits 90c on the temp gauge it clears. I'm pretty sure this is still down to the fact I'm getting air into the fuel as I put a small section of clear pipe in-line with the fuel feed to the filter and can see air pulsing through it. Question: there is a small device up near the tank with thomas magnete 89372a printed on it. Is this the fuel heater and if so could it be a probable cause? it appears linked into the fuel supply. I checked the voltage on it diconnected when the engine was running and was only showing 6 volts, should it have 12v?

Thanks again for your help.
 
Hi folks

Just found this thread - I have a 1.4 TDI 90 which exhibits similar problems, after standing for a while it has to turn over for a while before starting, occasionally will do the same when warm, then is fine for a few days or weeks! Occasionally also stutters when being heavy footed between 2-3k!

Since getting the car we've had cambelt replaced, and I asked them to check glowplugs at the same time, one of which needed replacement. No change. Tried using fuel conditioner stuff thinking maybe deposits around valve seats reducing compression, seemed to improve for a few days. Tried changing fuel filter, no different!

Has anyone else had success with theses issues?
 
What colour is the smoke that you are getting? i haven't got a clue about starting problem (sorry) but smoking until 90 on the temp gauge is reached sounds a bit like perished oil/water seals on the turbo unit. At least that's what happened on one of my petrol turbo'd cars way back. Random i know.

Sorry couldn't be of more help.
 
Last edited:
twiddler said:
Hi, this is my first post on the forum since buying my 2001 1.4 TDI in April and I really hope someone can help.

I've got a problem with cold starting, this started to happen about 2 months after I bought it, up until then it was fine. The problem is: When the engine is cold (only cold) I have to crank it for some time before it finally splutteres into life in a cloud of smoke. After it warms up the smoke clears and starts fine. Now I know a bit about cars, I changed the cambelt myself on this and the nearside shock.

First I suspected a clogged fuel filter so changed that; no difference. I bought the diagnostics cable, ran a test and it came back with error code 01406 - No Flame. This suggested air in the fuel line. This is probable; since the pump sucks rather than blows it could easily suck air in through a weak joining clip, but I've searched the car from end to end and from what I can see they look fine. I was advised to put some clear pipe up near the pump and look for air and sure enough I could see air bubbles in the fuel. This would fit with the symptoms - (air build up over time at the pump input causing an air lock - bleed issue). Also I think I've found a little (poor) workaround: by flooring the accelerator pedal just as I turn the key it appears to pull it over the dead spot. Though revving a cold engine can't be good for it. It certainly doesn't sound like its doing it any good. And desn't always work.

I've looked at all the posts on the forum that are similar - crank sensor / temp sensor etc and can pretty much discount these although I haven't totally written these off.

The temp sensor is a possible. If this fires up the glow plugs. I've yet to put a meter across the glow plug supply and see if they are getting a voltage and for how long? Is the temp sensor that is often refered to the one in the fuel line or in the bottom of the water tank?

If anyone has any suggestions they would be dearly welcome!

Many thanks
Click to expand...
 
Hi everyone, I am new to this forum & looking for some advise,
I have a Audi A2 Tdi 2004 with 160,000 miles on the clock, I drove the car on a 100 miles journey with no problems at all, left the car for a few days & on my return the car would not start, called a mechanic who sprayed some easy start in the air intake & the car started immediately, but now a lot of white smoke with smell of UN burnt diesel coming from the car, I have checked for signs of head gasket issues & the coolant looks very fresh, no misfire, no warning lights, just white smelly smoke,
Could any one suggest a magic cure,
Many thanks ,
Ami
 
Ami. Does the white smoke clear when the engine as warmed up say after 5 mins of running ?
White smoke is typically un burned fuel and the most likely cause is the glow plugs are not operating (fuel is injected but not burnt when cranking the engine, then eventually it fires on one or two cylinders then eventually on all three. The in burnt fuel already in the exhaust and takes some minutes to clear)
The glow plugs aid initial firing of the fuel and thus prevent the smoke


Sent from my iPhone using Tapatalk
 
depronman said:
Ami. Does the white smoke clear when the engine as warmed up say after 5 mins of running ?
White smoke is typically un burned fuel and the most likely cause is the glow plugs are not operating (fuel is injected but not burnt when cranking the engine, then eventually it fires on one or two cylinders then eventually on all three. The in burnt fuel already in the exhaust and takes some minutes to clear)
The glow plugs aid initial firing of the fuel and thus prevent the smoke


Sent from my iPhone using Tapatalk
Click to expand...

Hi:
I am very sorry for the late reply, as I dont really know how to find my posts.

I must say you were absolutely right about the white smoke which was as a result of un burnt diesel, this however was self inflicted as in my wisdom when the car wouldn't start I poured a small amount of fuel in each cylinder. however after a few long journeys it got burnt & the white smoke is now history.

Thanks again for your reply.
Ami
 
You must log in or register to reply here.
Back
Top