Tdi 130 Sluggish Starting

[ninjakev]

I wonder if its injecting too much fuel trying to avoid a stall? ....not sure how you cure that though!, but i think maybe 1 or 2 injectors are not working quite right so not getting combustion until more heat is generated.

 

Mine on a 0c morning will start without waiting for glowplug going off, and only protest a little.

 

Might it be a leaky injector then, dripping fuel into the cylinder overnight after a prolonged (8 hrs plus) period with the engine off? Is there residual pressure left over in the fuel rail when the engine is shutdown which would cause this phenomenon?

Edited January 26, 2007 by ninjakev

[Richard gal]

You could try some additive type stuff and really thrash it, Diesels like hard work to clean them out.

OR take the injectors out and get them serviced, much cheaper than replacing, i used to have a local firm who would just check them and charge nothing if they were OK.

[littledaz]

ninjakev,

 

I'm a little puzzled. (not difficult :) )

 

If I do the ignition key-on, key-off thing 3 or 4 times it starts perfectly

This is still possibly glow plug system issue. If you do that procedure every time does it cure the problem? Have you checked that you are receiving 12volts approx at the glow plug connectors to see if the relay is functioning. You could have a resistance issue that requires you to build the heat up gradually rather than them getting full power straight away. Might be a glow plug relay, i.e. poor contacts, or wiring issue.

 

As for the injector leaking - feasible. Can't say I've experienced it on a PD injector but, first time for everything. Would try new filter with some diesel conditioner to see if any improvement.

 

Is there residual pressure left over in the fuel rail when the engine is shutdown which would cause this phenomenon?

The PD diesel system uses a tandem pump driven from the camshaft to supply your injectors with the necessary pressure. When the engine is switched off, the pressure bleeds off back to the tank, so there is very little, if any, pressure in the system. The tandem pump is very efficient and can supply the necessary pressure almost instantly when cranked.

 

Have you checked for any fault codes. You can get them and have no warning light on?

 

I take you haven't noticed any coolant loss, just thinking about the misfire and smoke at cold start? Is it trying to burn off internally leaking coolant? I'm sure you would have said but, just thought I would eliminate it.

 

One other thing, did you check the resistance of the new glow plugs and compare them with your old ones? I have had new defective glow plugs before, especially non genuine ones.

 

Please report back before you spend any more of your hard earned cash. The more info you supply us, the easier it will be to diagnose.

[ninjakev]

littledaz,

 

I have no way of checking for any fault codes....

 

I did a comparison of the new glowplugs before fitting them and all four were 0.8 ohms. To be honest the old ones looked fine visually too, if a little sooty.

 

If I repeat the key on key off procedure on every cold start it does start better, as it does when I leave the ignition on for 20 seconds after glowplug lamp is off before firing it up.

 

The misfire at start is more of a diesel rattle, it runs a bit rough like this for maybe 10 seconds, almost like it's only running on 3 pots, accompanied by blue/grey smoke - definite incomplete combustion or overfuelling. This only occurs during the very first start of the day and also if the car has been used early in the day, left at work and then started on leaving work - say 8 hours later

 

There is no loss of coolant - I checked that too.

 

I was going to locate the glowplug relay and give it a check but haven't got round to that yet! I will check the voltage at the busbar tomorrow and report my findings.

 

It does not smoke unduly under hard acceleration or high load - I've even got her indoors to drive it and I've followed on the motorbike :)

 

Thanks for taking the time folks, this is bugging me now.

 

Kev

[burundi]

Any luck with this ninjakev? I am having what sound like exactly the same symptoms with an older tdi 90.

 

Glowplugs have been removed and tested on another battery (not my cars battery) and they work fine, they all get bright red all within a few seconds of being connected.

 

We've had the bus bar off the glowplugs and confirmed that we are getting 12v to each glowplug (11.8v roughly if I remember rightly)

 

The coolant temp sensor (four pin affair that sends the temp to the dash gauge and the ECM) has been replaced with a brand new one, made things even worse :16:

 

At the moment we have a variable resistor plugged into the connectors that would normally be connected to the sensor, giving a resistance of approx 4.5 Kohms back to the ECM. This seems to fool it (according to vag.com) that the coolant temp is about 1.8 degrees celsius and the bus starts lumpy, but it at least starts, more or less first or second time.

 

Not tried putting jump leads on and trying to start it, will have to try that on friday to see if it makes a difference.

 

Once it has got going the car runs fine though and I haven't noticed any smoking, but then I struggle to be behind myself at the best of times :16:

Edited April 4, 2007 by burundi

[burundi]

Tried it with jump leads on from the wifes car. Unplugged the resistor I had put in and re-connected back to the engines coolant sensor, vag-com reported coolant temp at about 9 degrees, glowplugs came on for a few seconds, heated them a couple of times before trying to turn it it over. The damn thing didn't want to start at all, I gave up after nearly choking myself on unburnt fuel.

 

I think the battery that is on is fine, back to drawing board on this. :D

[burundi]

ok, to recap my problem, TDI was suddenly starting badly, this went to very badly and then to running badly as well as starting badly and then to not running very well at all & not revving. Plumes of white smoke were coming out of the back when trying to start and when it was ticking over lumpily.

 

We firstly sent the fuel pump away to Fuel injection Services Ltd in Burscough in Lancashire. They found an issue with the stop solenoid which was apparently leaking, this may have been sucking air in and causing the starting problems.

 

My mechanic put the pump back on but it still wouldn't start or run properly. So we sent the entire vehicle to Burscough and they found the main crank timing out by 1 tooth so they reset the timing, reset the fuel pump timing and tuned it all up. They said they think the fuel pump was the original cause of the starting problems, we are not sure how the main timing belt got out by a tooth or why it was ok for so long after the belt was last changed and suddenly started going, perhaps the ECU was trying to hard to compensate for the pump timing or perhaps it was just coincdental and it was the pump timing that badly needed resetting and not the main crank timing.

 

Anyhow, the bus now starts perfectly and runs sweet as a nut \o/ I would recommend FIS Ltd, quick turnaround!

 

Hope this helps someone.

 

Cheers

Burundi

Edited May 4, 2007 by burundi

[ninjakev]

Righto...a bit of an update on the crap starting............

 

Due to work and moving house soon, I've not had a chance to take the car to get looked at, but the other day when turning the key to glowplug position I heard what sounded like fizzing - like when you crack open a bottle of pop. I turned the key a few times and each time there was a "fizz", but not as long as previously. After about 5 turns I started it, and it fired up pretty well.......it sounds like there is air getting into the fuel system from somewhere and this must be what is causing the "lean" start and smoke.

 

Would anyone know what the cause could be? Could it be the fuel is draining back somehow, leaving a vapour bubble in the lines, and how exactly could the fuel drain back?

 

Ta muchly.

[seatkid]

I think its more likely you have a faulty glow plug relay which is arcing - giving the fizz and reduced power to the glow plugs or Could also be the glow plug fuse / fuse holder......

[tim-spam]

I would also think that this is a possibility. However, the 'fizzing' noise is probably the electric fuel pump in the tank.

[ninjakev]

I would also think that this is a possibility. However, the 'fizzing' noise is probably the electric fuel pump in the tank.

 

The fizzing is coming from within the engine bay forward of the passenger seat area - I agree it may be caused by the fuel pump spinning up when turning the key, but the fizz is very noticeable..............so much so it's what made me take notice of it only recently. The fizz dies down after a few seconds so I can't see it being arcing across the relay contacts, certainly not with a 12V circuit anyway.

 

For peace of mind I'll check the relay.

 

Merci.

Edited June 20, 2007 by ninjakev