Cold Starting Issues - Running out of ideas!

[xman]

To depress you further I've just read a thread that claims his pd170 cold start issues was caused by a faulty dmf!

Basically anything that affects injection timing will make cold starts difficult as the 170bhp engine is highly sensitive to timing.

VCDS is a must as it often points straight to the problem.

[IngusSeflers]

As stated before my coolant sensor was reading 15c lower than temp - that's read from diagnostics as the gauge inside the car works fine.

Would that really be enough to cause my problem?

 

     YES! 

Open finally your ears and close the wallet!!! 

You need double pin coolant T° sensor.One part of that sensor is what you see on the Dash,another part is for ECM and 15°C is huge mistake in measurement and it CAN and DO affect start of the engine.

Buddy, stop wasting your time and money and change really faulty parts not those from some 'toughs'    :peek: 

For me it looks like; Hey Lads, I have problems with Cold Start and wrong T°readings from coolant sensor!

Should I change Tandem Pump and Glow Plugs? 

 

Are you serious???  :peek:

Edited 14 February, 2015 by IngusSeflers

[BlueVRSTom]

To depress you further I've just read a thread that claims his pd170 cold start issues was caused by a faulty dmf!

Basically anything that affects injection timing will make cold starts difficult as the 170bhp engine is highly sensitive to timing.

VCDS is a must as it often points straight to the problem.

I assume you mean ' DPF ' as DMF would mean the clutch side of life. I have had mine gutted out though.

[BlueVRSTom]

YES!

Open finally your ears and close the wallet!!!

You need double pin coolant T° sensor.One part of that sensor is what you see on the Dash,another part is for ECM and 15°C is huge mistake in measurement and it CAN and DO affect start of the engine.

Buddy, stop wasting your time and money and change really faulty parts not those from some 'toughs' :peek:

For me it looks like; Hey Lads, I have problems with Cold Start and wrong T°readings from coolant sensor!

Should I change Tandem Pump and Glow Plugs?

Are you serious??? :peek:

You really are quite funny, which is nice to read after the stress of all my car problems.

I shall locate a new sensor, get it fitted and report back!

[IngusSeflers]

I shall locate a new sensor, get it fitted and report back!

 And don't come back without results!

[xman]

I assume you mean ' DPF ' as DMF would mean the clutch side of life. I have had mine gutted out though.

No, it was DMF dual mass flywheel that had failed. I'm not sure how that effects timing, but the poster was quite adamant.

http://forums.tdiclub.com/showthread.php?t=365616

See last post on page 2

Edited 14 February, 2015 by xman

[xman]

Think you need part no 06A 919 501 A

Info taken from http://www.partscats.info/skoda/en/?i=cat_vag_models&brand=sk&number=81&set=96&ein=2007&f=419&hauptgr=1234567890&hg=1&grf=012180419&bf=12180&hgug=121&ug=21&parent_id=102176&detail_id=102184

Please double check it though.

[BlueVRSTom]

Okay thanks Xman

I'm having some troubles though. I've found what I believed to be a temp sensor but when you disconnect it and pull it out - diesel fuel leaks out so that must be the fuel sensor.

I can't find either coolant sensor. I need to make sure I get the sensor for the ECU not for the dash.

[Guest]

I, like others feel your pain and hope you get to the bottom of this.

However I still think it's more a fuel issue than sensor related, even though I suggested it a while back.

If after replacing the suspect sensor I'd backtrack from the newly fitted tandem pump with a fine tooth comb, not suggesting you haven't already.

Out of curiosity, if starting from cold when it needs lots of cranking, when it starts does it do so reluctantly/smoothly/harshly, is there abnormal smoke from the exhaust that would indicate built up unburned diesel?

Or is it smooth to start without any undue smoke?

Just thinking out loud...

[xman]

Okay thanks Xman

I'm having some troubles though. I've found what I believed to be a temp sensor but when you disconnect it and pull it out - diesel fuel leaks out so that must be the fuel sensor.

I can't find either coolant sensor. I need to make sure I get the sensor for the ECU not for the dash.

Yes there is a fuel temperature sensor just before the tandem pump too! That can cause problems too!!

Youve told us its 2007 but not told us the engine code yet...without which I dont know where to look.

Edit: I think i

G83 sensor is here

http://www.partscats.info/skoda/en/?i=cat_vag_models&brand=sk&number=81&set=96&ein=2007&f=419&hauptgr=1234567890&hg=1&grf=012110409&bf=12135&hgug=121&ug=21&parent_id=101414

Item 10 in the picture

G82 sensor is probably in top radiator hose - follow it back to the block and there is probably a plastic t piece as earlier pic.

Edited 14 February, 2015 by xman

[IngusSeflers]

You need to change #5,#18 is radiator output T° sensor it makes some other functions. 

[BlueVRSTom]

Engine code is BMN

Is that all that you need to know?

[BlueVRSTom]

I, like others feel your pain and hope you get to the bottom of this.

However I still think it's more a fuel issue than sensor related, even though I suggested it a while back.

If after replacing the suspect sensor I'd backtrack from the newly fitted tandem pump with a fine tooth comb, not suggesting you haven't already.

Out of curiosity, if starting from cold when it needs lots of cranking, when it starts does it do so reluctantly/smoothly/harshly, is there abnormal smoke from the exhaust that would indicate built up unburned diesel?

Or is it smooth to start without any undue smoke?

Just thinking out loud...

After a long period of cranking when the car finally fires up it then idles and runs 110% normal with no problems.

It's literally just getting the car started to begin with and yes LOTS of smoke exits the exhaust the moment it fires up which is unburnt diesel.

[freelanderman]

I know you have had the heater plugs renewed, but has anyone tested to see if they are actually working. Have you got a high back pressure in the engine, oil trying to splash back up the dipstick tube with the dipstick removed while the engine is running.

Ask the garage you are dealing with to test the glow plugs with a current clamp, have a compression test done,change the coolant sensor if it is faulty.Is the cranking speed of the starter motor sufficient.

Is the wiring loom to the injectors been checked for possible faults. Has the camshaft posistion sensor been tested, failure of this can cause very slow starting.

Edited 14 February, 2015 by freelanderman

[xman]

Glowplugs are only essential with sub zero temperatures. Pd and tdi engines will start fairly easily down to 0 deg C without them, maybe run a little rough for a couple of seconds.

Vcds scan would take a lot of this guesswork out.

[xman]

Engine code is BMN

Is that all that you need to know?

Change item #5 in Ingusselfers diagram...part no as stated earler.

http://www.ebay.co.uk/itm/SKODA-FABIA-OCTAVIA-COOLANT-TEMPERATURE-SENDER-SENSOR-SWITCH-06A919501A-/180746530647?pt=LH_DefaultDomain_3&hash=item2a15552f57

[freelanderman]

Glowplugs are only essential with sub zero temperatures. Pd and tdi engines will start fairly easily down to 0 deg C without them, maybe run a little rough for a couple of seconds.

Vcds scan would take a lot of this guesswork out.[/

Glow plugs also help easy starting on high mileage engines, and are designed to assist starting below 9 degrees C.

[Guest]

When cranking from cold do you depress the accelerator?

I don't mean calling it fat and unattractive!

Smoke on startup indicates poor combustion, so let's assume it's getting fuel OK, it just isn't burning it.

If you aren't force feeding it diesel by depressing the accelerator I'd be inclined to think evenly worn piston rings as you say it idles fine and not lumpy etc.

Has it had proper oil changes/booted to death?

If compression is low then it will take a cold engine a while to start.

Again I'm just thinking out loud and am reminiscent of starting sh@gged out 2-stroke motorcycles when I was young.

[BlueVRSTom]

Not ruling this out but I've been reading on the Darksides websites and failing coolant temp sensors cause problems with a warm engine not cold?

Although I have stumbled across the fuel pressure sensor on their website ( the same sensor I unplugged today )

When I unplugged it and left it as such, my car still struggled to start but drove fine with no fault codes - that can't be right can it if it's been unplugged?

[IngusSeflers]

Stop reading-acting!!! Change that Freaking sensor and see what happens!!!

[BlueVRSTom]

Stop reading-acting!!! Change that Freaking sensor and see what happens!!!

Okay!!! Just before I purchase it tomorrow, I'm going to locate it and unplug it and see if it makes any difference.

But I'm going to order 06A 919 501 A and swap it with the sensor at #5

[Guest]

Do you feel car lacks engine braking, especially for a diesel?

[IngusSeflers]

 I'm going to locate it and unplug it and see if it makes any difference.

 

Example. At the moment you have ~15 degrees below real temperature, if you disconnect plug from sensor system will recognize -40°C. So I guess you'll not see any difference.

[freelanderman]

Not ruling this out but I've been reading on the Darksides websites and failing coolant temp sensors cause problems with a warm engine not cold?

Although I have stumbled across the fuel pressure sensor on their website ( the same sensor I unplugged today )

When I unplugged it and left it as such, my car still struggled to start but drove fine with no fault codes - that can't be right can it if it's been unplugged?

There is no fuel pressure sensor on your car, the sensor is a fuel temp sensor and failure of this has little effect on thhe starting of the car as the ecu reverts to a default value. The only oddity about the fuel temp sensor is it needs a dedicated VAG fault cod reader to register a fault witth it.

[BlueVRSTom]

Just while I'm waiting for new temp sensor to arrive and what not. I thought I'd retrace my steps as its better than just sitting and wondering.

I assume this is the correct battery for the car.

Also I don't know if it is a fuel issue as when the car starts load of grey/black smoke comes out the exhaust. If it was petrol I'd say spark plugs hands down.